Determination of the best volume of perfluorocarbone to ensure partial liquid ventilation in the pig with ARDS

Critical Care, Mar 2000

JM Constantin, G Gindre, JD Segrell-Therre, JE Bazin, P Schoeffler

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Determination of the best volume of perfluorocarbone to ensure partial liquid ventilation in the pig with ARDS

Crit Care Critical Care The Official Journal of the Critical Care Forum Editor: Jean-Louis Vincent Chairman: J-L Vincent Manager: Carl Vanhaesendonck 0 1 2 4 5 6 7 8 9 0 19th International Symposium on Intensive Care and Emergency Medicine Brussels, Congress Center , 16-19 March 1999 1 NW Knudsen, MW Sebastian, RA Perez-Tamayo, WL Johanson and SN Vaslef Duke University Medical Center , Durham, NC , USA 2 C Gorman, T Rogers, J Price, A Waboso, L Flackett and N Stallard Intensive Care Service, University Hospital of Wales , Cardiff, CF4 4XW , UK 3 Norwegian Air Ambulance , Stavanger , Norway 4 K Kokkinis, T Vrettos, K Lefkaditi, P Manolopoulou and K Zbouki Department of Anesthesiology and Intensive Care Medicine, University Hospital of Patras , Greece 5 K Yasumoto and I Kagami Department of Anesthesiology, Showa University Hospital , 1-5-8 Hatanodai Shinagawa-ku, Tokyo , Japan 6 MY Yassin Libanese University School of Medicine, Department of Internal Medicine, Pulmonary and Critical Care Division, Hammoud Hospital , Sidon- Lebanon 7 RD Branson, RS Campbell, M Ottaway and JA Johannigman University of Cincinnati, Department of Surgery 8 JG Hardman Department of Anaesthesia and Intensive Care, University of Nottingham , UK 9 D Kindgen-Milles, A Gabriel, R Buhl, H Böhner and E Müller Department of Clinical Anaesthesia, Heinrich-Heine-University , 40001 Düsseldorf, FRG s of Posters A d'Hollander (Brussels, Belgium) Scientific advisors - With the collaboration of: Poster abstracts 1 A prospective study of the incidence of iatrogenic ocular damage in critically ill patients Crit Care 1999, 3 (suppl 1):P1 Introduction: Critically ill patients requiring intensive care are at risk of iatrogenic ocular damage. Studies have reported an incidence of eye problems of up to 40% in critically ill ventilated patients. We conducted this study to assess the incidence of ocular complications in our intensive care unit where all patients are cared for according to an eye care standard. Methods: All ventilated patients over a 2 month period were included. Ophthalmic assessment was performed on admission and repeated every other day during the period of ventilation. At each assessment the average Ramsey sedation score over the previous 24 h, the presence of tracheal secretions and the presence of ventilation associated pneumonia was noted. Eye care performed was recorded. Results: Sixty patients were included. One patient developed corneal exposure keratopathy. No patient developed conjunctivitis or corneal ulceration. Further advice on appropriate measures of eye care was given in five cases (8%). Nine patients (15%) had large amounts of respiratory secretions with positive microbiological results. Conclusion: This study confirms that the use of an eye care standard is associated with a low incidence of ocular surface complications. The incidence of ocular complications in this group of patients is far lower than previously described. Intensive care unit procedures: cost savings and patient safety Crit Care 1999, 3 (suppl 1):P2 Introduction: Intensive Care Unit (ICU) management of critically ill patients often includes the requirement for tracheostomy and feeding access, most often a pecutaneous endoscopic gastrostomy (PEG). Although advances in ICU airway management include percutaneous tracheostomy, semi-open tracheostomy and conventional tracheostomy, the majority of critically ill surgical and injured patients still receive open tracheostomy in the Operating Room at Duke University Medical Center (DUMC). Although percutaneous tracheostomy is performed routinely in many medical ICU settings, in high risk surgical and trauma patients who often have unstable cervical spine injury and tissue edema, direct visualization of the cervical structures and trachea is imperative during tracheostomy. We have undertaken open tracheostomy and PEG in the ICU in selected patients as part of a collaborative, mulitidisciplinary ICU patient management strategy at DUMC. This initiative has been undertaken to address the risk of patient transport, the inappropriate use of OR time, and the cost to the patient as part of an effort to standardize and improve patient care. Methods: After informed consent, utilizing DUMC conscious sedation protocol, full ICU monitoring, and sterile OR technique, 13 tracheostomies and 8 PEG placements were performed in 13 patients in the ICU since July, 1998. There were no complications. Operating Room costs include basic room fee and charge per minute for general surgery and anesthesia and the anesthesia professional fee. Surgical professional fee, tracheostomy tube cost, and gastroscope maintenance are identical and not included in the analysis. ICU costs include gowns, gloves, drapes and tracheostomy tray. For purposes of analysis, OR tracheostomy and OR PEG times were defined as 120 min and 60 min respectively; although analysis of fiscal year 1997–1998 yield widely divergent average OR times for these procedures. Results: A table of cost comparison for individual procedure, total to date and associated cost savings are shown below. PEG (n = 8) Conclusion: Tracheostomy and PEG placement in the ICU in selected patients are safe, avoid patient travel, improve OR utilization and show a significant reduction in cost. Fiberoptic bronchoscopy of the intubated patient with life-threatening hemoptysis H-J Düpree, J-C Lewejohann, J Gleiß, E Muhl and H-P Bruch Medical University of Luebeck, Dept. of Surgery, Ratzeburger Allee 160, 23538 Luebeck, Germany. E-mail: Crit Care 1999, 3 (suppl 1):P3 Introduction: Bleeding into the tracheobronchial tree is a potentially fatal occurrence for intubated patients. The subsequent acute respiratory failure requires an effective therapy. Fiberoptic bronchoscopy represents an easy available technique for the diagnosis and treatment of this type of hemoptysis. Methods: We show the bronchoscopic management of endobronchial bleeding in intubated patients at our ICU. During the period 7/97–12/97 seven consecutive patients with acute endobronchial bleeding were treated with fiberoptic bronchoscopy. All patients received an endobronchial instillation of epinephrine and physiological saline solution (1:10 000–100 000). Critical Care 1999, Vol 3 suppl 1 Goiter, large retrosternal, sternotomy Stenosis of the left internal carotid artery Ruptured abd. aortic aneurysm Axillo-bifemoral bypass-infection Aspergilloma left lung, acute myeloic leucemia Lung contusion, polytrauma Acute abdominal pain, urosepsis, nephrectomy SaO2 [%] before treatment Results: Control of bleeding was achieved with 1 to 20 (m ± SEM: 5.86 ± 0.93) bronchoscopic interventions. Hemostasis was accomplished in a period of 0.5 h and 10 days. Cardiocirculatory instability was observed in five patients. One patient died because of persistent bleeding caused by severe aspergillosis. Six patients survived without further interventions. Conclusion: Endobronchial instillation of epinephrine and physiological saline solution represents an effective method in case of lifethreatening hemoptysis in intubated and mechanical ventilated patients. The compliance characteristics of the Portex Soft-Seal cuff improves seal against leakage of fluid in a pig trachea model PJ Young and MC Blunt ICU, Queen Elizabeth Hospital, Kings Lynn, PE30 4ET, UK Crit Care 1999, 3 (suppl 1):P4 A high volume low pressure (HVLP) cuff does not protect the lower airway from contamination by material leaking along longitudinal folds within the cuff wall [1]. This is a major factor in the pathogenesis of ventilator associated pneumonia [2]. The combination of shape and high compliance of the Portex Soft-Seal cuff might eliminate the folds in the cuff walls circumferentially for a portion of the cuff and prevent leakage. We have tested the SoftSeal cuff in a pig trachea model to establish whether protection against leakage is better than that afforded by standard HVLP cuffs. Method: The Portex Soft-Seal, Mallinckrodt Hi-Lo, Sheridan Preformed and Portex Profile size 8 mm internal diameter HVLP cuffed tracheal tubes were assessed for leakage of dye placed in the subglottic space to the trachea in a benchtop ventilation model and in six isolated pig tracheas. All cuffs were inflated at 30 cmH O pressure. 2 Results: There was no leakage in the ventilation model or in the pig tracheas with the Portex Soft-Seal group, but rapid leakage occurred in all the pig tracheas for the standard HVLP cuffs. Conclusion: This benchtop study suggests that the improved HVLP cuff compliance characteristics and shape of the Portex Soft-Seal cuff might be beneficial in the prevention of leakage of fluid to the lungs known to occur with HVLP cuffs. Colibri coloriometric technology rapidly detects oesophagal intubations Crit Care 1999, 3 (suppl 1):P5 Introduction: Rapid verification of correct placement is extremely important [1,2]. We have tested a new coloriometric CO2 detection indicator meant for this purpose [3]. Methods: An entdotracheal tube was placed both in the trachea and the oesophagus in otherwise healthy patients undergoing elective surgery under general anaesthesia. We compared the four first ventilations of the endotracheal and oesophageal tube using capnography and a Capno Bri indicator with four different colour Poster abstracts 3 gradings. (Blue ~ 0.5%, dark green ~ 1.0%, light green ~ 3.0% and yellow ~ 4.0%) especially suitable in emergency situations where capnography is not available Results: In all patients (n = 9), the indicator confirmed correct placement of the tube in the trachea at the first ventilation (yellow color). The indicator also verified incorrect oesophageal placement at the first ventilation in all patients (blue color). These results were confirmed by the capnography. Conclusion: The Colibri technology is a reliable technique for confirmation of correct endotracheal tube placement. It may be References 1. Sum Ping ST: Accuracy of the FEFCO2 detector in the assessment of endotracheal tube placement. Anaest Analg 1992, 74:415-419. 2. Sayah AJ: End-tidal CO2 measurement in the detection of esophagus intubation during cardiac arrest. Ann Emerg Med 1990, 19:8. 3. Singer M: Colibri: a new means of CO2 detection. ESA Congress in Barcelona 1998. Lung volume and oxygenation changes with a closed suction system (CSS) in patients undergoing volume controlled ventilation (VCV) M Cereda, E Colombo, F Villa, G Greco, L De Marchi and A Pesenti Istituto di Anestesia e Rianimazione, Ospedale S. Gerardo, via Donizetti 106, Monza (MI) 20052, Italy Crit Care 1999, 3 (suppl 1):P6 We wished to measure changes in lung volume (DLV), airway pressures, and oxygenation during tracheal suctioning performed with a CSS and with an open suction system (OSS). We enrolled 7 adult patients, sedated and paralyzed, VCV ventilated by a SERVO 900C ventilator (Siemens, Sweden) with PEEP ³5 cmH O and FiO2 ³ 0.4. Keeping all remaining ventilatory set 2 tings unchanged, we set trigger sensitivity at –2 cmH2O, inspiratory time at 25%, inspiratory pause at 10%. We performed four suctioning manouvers at 20 min intervals using alternatively a CSS and an OSS. With both systems, we used 12 F size catheters. We performed no pre-oxygenation manouvers. Suction was applied for 20 s at a pressure of 100 cmH2O. We continuously recorded signals of respiratory inductance pletismography (RIP, Respitrace Plus, NIMS, FL), arterial oxygen saturation (O2Sat) by pulse oxymetry, and airway pressures. We obtained DLV as the change in the RIP signal measured during VCV and during suction. We measured Respiratory Rate (RR), peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), and mean airway pressure (MAP) during VCV and during suction with the CSS. Results: variables are reported as mean ± DS. PIP (cmH2O) PEEP (cmH2O) MAP (cmH2O) *P < 0.01 vs CSS, †P < 0.05 vs VCV, ‡P < 0.01 vs VCV Comment: the use of the OSS resulted in discontinuation of ventilatory support with a loss in lung volume and in O2Sat. The CSS effectively preserved lung volume and oxygenation by maintaining airway pressures during the suction manouvre. The increase in RR observed with the CSS was due to activation of the trigger mechanism. Balloon laryngoscopy reduces head extension and blade leverage in patients with potential cervical spine injury SD Mentzelopoulos, MV Tsitsika, MP Balanika, MJ Joufi and EA Karamichali Department of Anaesthesia, Evangelismos General Hospital, 45 Ypsilantou Street, GR-10676, Athens, Greece Crit Care 1999, 3 (suppl 1):P7 Background: In trauma patients, rigid cervical collar placement reduces head extension (HE) during laryngoscopy [1]. In patients with difficult airway, upper teeth or gums may be traumatized by excessive laryngoscope blade levering motion (LBLM) needed for laryngeal visualization [2]. The current study aims to compare, under stimulated spine precautions, HE and LBLM upon maximum glottic exposure (MGE) achieved with #4 conventional Macintosh blade (CMB) and #4 modified Macintosh blade (MMB) carrying two 10 Foley catheters (Fig. 1). Methods: Anaesthesia was induced in 17 male, ASA I, Mallampati I, elective surgery patients. Spine precautions included rigid board placement under the shoulders and occiput and a rigid collar placement round the neck. Laryngoscopy was performed twice, changing between MMB and CMB. Before each laryngoscopy, the patients head was placed in the neutral position. MMB laryngoscopy technique consisted of MMB tip insertion into vallecula, right catheter balloon inflation with 2 ml air and MMB elevation until MGE achievement. The angles of laryngoscope handle axis (Fig. 2 AH) and of maxillary molars occlusal surface axis (OS) relative to horizontal (angles â1 and â2 in Fig. 2) were recorded upon MGE. Angles â1 and â2 were measured with an automatic angle finder (Fig. 1). The difference of 90°–â2 was defined as HE angle and the difference â1–â2 was defined as LBLM angle (angle â3 in Fig. 2), He and LBLM angles were compared with paired t test; P < 0.05 was considered statistically significant. Results: MMB laryngoscopy resulted in significantly less HE and LBLM than CMB laryngoscopy (P < 0.001). Results and summarized statistics are presented in the Table. Values are shown as Critical Care 1999, Vol 3 suppl 1 means ± SD, Cormack-Lehane grade of laryngoscopic view was £II during all laryngoscopies. Laboratory study of new technique using a one-pass dilator for percutaneous dilatational tracheostomy P Ciaglia and W Marx St Elizabeth Medical Center, 2215 Genesee Street, Utica NY 13501, Masonic Medical Research Laboratory, Utica, SUNY HSC, Syracuse, NY, USA Crit Care 1999, 3 (suppl 1):P8 Background and objectives: Percutaneous dilatational tracheostomy requires the use of several dilators of increasing size. It would be a marked advantage to use only one dilator to achieve the desired 36 F. This report presents preliminary animal studies using freshly sacrificed dogs, adult pig tracheas fresh from the slaughterhouse and live piglets. Methods: The usual technique for percutaneous dilatational tracheostomy was first followed to insert a guidewire into the trachea. A well-lubricated, one-pass, long, tapered dilator was threaded over the guidewire into the trachea. With twisting, it was inserted to the 36 F level. The one-pass dilator was removed leaving the guidewire in place and the chosen tracheostomy tube was passed over the guidewire into the trachea using the usual technique of percutaneous dilatational tracheostomy. Results: A total of 50 dog cadavers and 25 slaughterhouse sheep tracheas were successfully tracheotomized using the one-pass dilator employing 7 and 8 mm I.D. tubes. Six live piglets were finally used successfully. No perforations or false passengers occurred. Concusions: A one-pass technique was used successfully on fresh dog cadavers and should be evaluated on human beings. Percutaneous dilatational tracheostomy with a lightwand device Crit Care 1999, 3 (suppl 1):P9 Percutaneous dilatational tracheostomy (PDT) is a new technique which shares the same indications as surgical tracheostomy. We describe our experience with the PDT in combination with tracheal transillumination. Patient population: Elective PDT was performed in 55 critically ill patients, mean age 54.5 ± 16 (22–72), intubation time 6.5 ± 3.2 (3–14) days. Technique: The procedure was undertaken on the bedside using the Griggs-Portex PDT set as has been already described [1]. Before cannulation of the trachea the trachlight device (trachlight, Poster abstracts 5 Leardal Medical) was inserted into the endotracheal tube with the tip at the end of the tube. By pulling back the endotracheal tube with the trach-light we examined the anatomy of the trachea and the location of the first and second tracheal rings. Besides the proper position of the end of the tube above the first tracheal ring was achieved. Afterwards we continued with the PDT technique. At the end the exact tracheotomy site and the correct placement of the tracheostomy tube was evaluated by endoscopy. Results: The procedure lasted from 7 to 21 min (m.v. 9.5 min). The maneuver with the trachlight device lasted between 40–80 s Perioperative complications are listed below: 1) Hemorrhage minor: 2 patients Hemorrhage major: 0 patients 2) Premature extubation of the translaryngeal tube: 0 patients 3) 4) 5) Puncture of the endotracheal tube/cuff: 0 patients Paramedian puncture of the trachea: 0 patients Hypoxemia: 0 patients Conclusion: PDT is a simple bedside procedure with a low complication rate. The combination with the trachlight device gives the opportunity for better identification of the anatomy of the trachea as well as the correct placement of the endotracheal tube above the first endotracheal ring. These contribute to better conditions for safe and accurate tracheal puncture and cannulation. Percutaneous dilatational tracheostomy (PDT): a report on 103 consecutive cases of the translaryngeal tracheostomy (TLT) technique A Karnik and JW Freeman Featherstone Department of Intensive Care, Queen Elizabeth University Hospital, Birmingham B15 2TH, UK Crit Care 1999, 3 (suppl 1):P10 Introduction: We describe our experience with the TLT technique, which is a purely dilatational PDT with low inherent risks. The technique has the additional benefit of maintained ventilation and airway protection. Technique: The TLT consists of a reinforced tracheostomy tube, with an integral dilator, which is pulled out between tracheal rings following retrograde insertion through the larynx [2]. A cuffed oral 5mm-tracheal tube inserted past the proposed stoma site maintains ventilation and airway protection. We prospectively collected data in 103 consecutive patients, 56 males and 47 females, undergoing this technique. The authors (JWF & AK) performed tracheostomies on all patients (16 to 88 years old). Pre-existent coagulopathy was not corrected. Indications for tracheostomy were mainly for term ventilation (39) and weaning difficulties (44). Results: 102 tracheostomies were performed successfully. One was converted to a Ciaglia technique after accidental decannulation. Mean duration of operative procedure was 13.9 min. The INR ranged from 0.8–2.6, (mean 1.3), platelets ranged from 23–667 × 109 (mean 184 × 109). There were six transient episodes of hypoxia (SpO2<90%), three cases of hypotension, two related to the anaesthetic technique and one following traumatic intubation. There were four episodes of accidental decannulation and one case of minor subcutaneous emphysema. There was one case of moderate blood loss (100–250 ml). There was one episode of loss of airway, in a patient who was difficult to intubate (Gr. III). We had two cases of wound infection associated with pre-existent systemic bacteremia. Total duration of the tracheostomy ranged from 1–65 days. Total closure of the stoma took a mean of 4 days (range 2–9 days). The resultant scar was minimal. Conclusion: This pure dilatational and bronchoscopically visualised method is easy to perform with training. It is worthy of consideration in patients with coagulation abnormalities. We feel it offers better control over the airway than other available techniques although there is a definite risk of decannulation while withdrawing the cannula over the obturator. The overall morbidity of this technique is low. Independent lung ventilation using a double-lumen endobronchial tube by nasotracheal intubation Crit Care 1999, 3 (suppl 1):P11 Independent lung ventilation (ILV) is effective for the patient who is suffering from unilateral lung disease. When we ventilate the patients with ILV, they should be intubated with a doublelumen endobronchial tube. While ILV is continued for some time a number of difficulties related to the management of the doublelumen endobronchial tube (DLT) arise. Movements of the patient and routine turning of the patient threaten the DLT position and can lead to loss of lung isolation or lobe occlusion. Nasal intubation is better suited for long-term intubation than oral intubation because it is safer for equipment attachment. We have ventilated six patients (Table) with ILV using the DT by nasotracheal Post upper lobectomy 155.5 Aspiration pneumonia 145 Aspiration pneumonia 153 Critical Care 1999, Vol 3 suppl 1 intubation for 25 to 120 h. We intubated Portex #5.5 DT for all cases. There was no case in which DLT was required to correct its position during ILV. Although we examined the condition inside the nose, there was no severe damage by the DLT. We concluded that nasotracheal DLT intubation was done safely and could be used for ILV up to 7 days. The effect of dexamethasone on the incidence of post extubation stridor in pediatric patients AK Kalloghlian, BM Pittappilly and NT Matthews The Pediatric Intensive Care Unit, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354 Riyadh, Saudi Arabia Crit Care 1999, 3 (suppl 1):P12 Post extubation stridor is due to reactive subglottic laryngeal edema at the cricoid ring. Dexamethasone has been used to reduce the incidence of stridor in such patients. The evidence in the literature however is not conclusive. We conducted a prospective, randomized, double blind study of dexamethasone versus placebo to assess the efficacy of dexamethasone in reducing the incidence of post extubation stridor in children. Fifty-one patients without any known preexisting upper airway problems were studied. There were 27 patients in the treatment group and 24 in the placebo group. Both groups had similar weight, age and length of intubation. Dexamethasone was given at a dose of 0.6 mg/kg at 12 h and 1 h prior to extubation for a total of 2 doses. The control group received placebo at corresponding times. There was no statistical difference in the incidence of post extubation stridor in the two groups. Ten of 24 children in the placebo group (41.7%) and 8 of 27 (30%) in the dexamethasone group developed stridor (P = 0.39). There were 3 patients in placebo group and 1 in dexamethasone group that needed reintubation, but again the difference was not statistically significant (P = 0.33). This study, although with relatively small sample size, suggests that routine use of dexamethasone to prevent post extubation stridor, in children without any known upper airway abnormality, is not warranted. Evaluating the effect of steroids on the incidence of reintubation rates in children with laryngotracheobronchitis J Rajah, J Riera-Fanego, J Keeton, A Ramjee, R Bhana and H Hon Intensive Care Unit, Chris-Hani Baragwanath Hospital, University of Witwatersrand, P O Bertsham, 2013, South Africa Crit Care 1999, 3 (suppl 1):P13 Introduction: Postextubation stridor is a serious problem in children with an incidence of up to 33% in electively intubated children. Our aim was to determine whether steroids decreased reintubation rates and to identify other risk factors for reintubation. Methods: Retrospective analysis (1994–1996) of the 82 children (72 received steroids). Steroids were categorized according to the type used and the time of administration. Recognized risk factors for postextubation stridor including age (<1 and >1 year) and duration of intubation (<120 and >120 h) were analyzed. Results: There was no significant difference in either the preintubation grade or stridor (P = 0.67) in both outcome groups (reintubated 22/23 grade 3 and not-reintubated 50/59 grade 3) or in the postextubation grade of stridor between both groups (P = 0.1). Neither type of steroid (P = 0.32), nor time administered (P = 0.79), nor age (P = 0.22) nor duration of intubation (P = 0.35) was found to significantly influence reintubation rates. Conclusion: The prophylactic use of corticosteroids in routine elective extubations for laryngotracheobronchitis cannot be rec Advantages of a new humidification technique Intubation (2 days) ICU stay (days) ommended, based on current findings. Overall, 28% of all patients needed to be reintubated. However, reintubation seems to be correlated best with atelectasis rather than the degree of postextubation stridor. G Via, M Olivei*, A Palo, S Neri, G Ragni, M Bertolini, N Fusilli, F Capra-Marzani, G Rodi, G Iotti and A Braschi Anestesia e Rianimazione Io, *Lab. Tecn. Biomediche IRCCS S. Matteo P. le Golgi 2 27100-Pavia, Italy Crit Care 1999, 3 (suppl 1):P14 Recently, an active HME (AHME) (Humid-Heat, Gibeck) has been developed. The AHME combines a HME with a unit which adds humidity and heat to the patient-side of the HME. The supply of humidity and heat is automatically regulated, in order to achieve 100% humidity of inspired gases at 37°C. The operation of AHME requires only the user-set input of the patient minute Poster abstracts 7 ventilation. We evaluated the potential advantages of the AHME over a conventional active humidifier. Methods: The study included seven mechanically ventilated patients. In each patient, the AHME was used for 24 h and then substituted with a conventional active humidifier (F&P) (MR730, Fisher & Paykel) with a heated wire in the inspiratory limb, for the next 24 h. AHME was preset to keep the temperature of inspired gases at 37°C. The F&P was set to 37°C in the humidifier-chamber, and to 37°C at the Y piece. The AHME and the F&P were compared in terms of: humidity and temperature output, water consumption and condensate in the water traps. The humidity output was evaluated on the basis of the condensate in the flex tube, which was scored from 0 (absent) to 3 (excessive). Results: Minute ventilation did not differ during application of AHME and of F&P. Both devices kept the set temperatures, and provided adequate humidification, as assessed by the condensate in the flex tube. However, when the F&P was used, there was formation of condensate in the ventilator tubings, and the water traps needed to be emptied on average eight times (range: 6–9) per day. Minute ventilation (l/min) Insp. gases temperature (°C) Condensation in the flex tube (score) 2 ± 0 No. of water traps emptying Quantity of H2O in the water traps H2O consumption (ml) means ± SD; Student t test. No condensation of water was found in the ventilator tubings with AHME. Compared with F&P, the AHME remarkably reduced the water usage. Conclusion: Compared to a conventional active humidifier, the AHME provides equivalent humidification, with the advantages of both reducing the time-expenditure for handling, and of eliminating the risk caused by water condensation in the ventilator tubings. Heat and moisture exchanger PALLBB22-15F can prevent ventilator-associated pneumonia (VAP) in short term mechanically ventilated ICU patients Crit Care 1999, 3 (suppl 1):P15 Introduction: VAP is a serious infection with a mortality rate exceeding 50%. It also leads to an increase in the duration of the treatment and adds to hospital costs. Bacteria, in intubated patients, may be directly inoculated into the endotracheal tube from the hands of medical personnel or from contaminated respiratory therapy equipment (i.e. humidifiers). We tried a heat and moisture exchanger to substitute the conventional ventilator humidifiers to prevent VAP in the ICU setting. Methods: Subjects were intubated and attached to the conventional respiratory assistance cascades in the first year of the study (July 1992–June 1993). Retrospectively, cases of VAP were calculated prospectively, during the following year (July 1993–June 1994), subjects were intubated and attached to respiratory assistance cascades; but PALL filter, a heat and moisture exchanger, was in-line and the machine humidifiers were bypassed. The cases of VAP were calculated. Study population: Intubated ICU patients with normal CXR on admission to the unit. Results: VAP rates decreased in the group of HMEF dramatically in comparison to the conventional humidification method (see Table below). Humidification method Total patients in group VAP rate, incubated 1 day VAP rate, intubated 2–4 days VAP rate, intubated > 5 days Conclusion: We concluded that heat and moisture exchanger filters can prevent VAP in short term mechanically ventilated ICU patients, and can halve its rate in long term durations. A clinical evaluation of a new humidifier in long-term mechanical ventilation M Olivei*, G Via, A Palo, S Neri, G Maggio, T Mediani, C Galbusera, M Belliato, E Haeusler, G Iotti and A Braschi Anest. e. Rianimazione Io *Lab. Tecn. Biomediche IRCCS S. Matteo P. le Golgi 2 27100-Pavia, Italy Crit Care 1999, 3 (suppl 1):P16 The adequacy of humidification of heat and moisture exchangers (HMEs) during long-term mechanical ventilation is still controversial. Recently, an active HME (AHME) (Humid-Heat, Gibeck) has been developed. This AHME combines a HME with a unit which adds water and heat between the patient and the HME. The AHME automatically regulates the water and heat supply. The only user-set input for AHME is the minute ventilation (V’e) of the patient. We evaluated the AHME efficiency for humidification during long-term mechanical ventilation. Methods: The AHME was used for 5 days on seven patients which were mechanically ventilated in different modes. On each Critical Care 1999, Vol 3 suppl 1 day we measured the number of tracheal aspirations, the secretions characteristics, the condensate in the flex tube and in the water traps, the airway temperature, the number of changes of the V’e setting on AHME. A chest X-ray and a bronchoscopy were performed on days 1, 3 and 5. We scored the secretions characteristics and the condensate in the flex tube from 0 (insufficient) to 3 (excessive), the atelectasis at chest X-ray from 0 (absent) to 2 (evident), and the bronchial occlusions at bronchoscopy from 1 (absent) to 4 (complete). Results and conclusion: AHME provided adequate humidification over the 5 days, as indicated by the secretions characteristics and Quantity of secretions (score) Viscosity of secretions (score) Condensation in the flex tube (score) Bronchial obstruction (score) RX atelectasis (score) Insp. gases temperature (°C) Nr. of changes of V’e set on AHME means ± SD. ANOVA. by the absence of new atelectasis and of secretions accumulation in the bronchi. The temperature of inspired air was adequate. The value of V’e set on the AHME was changed on average twice (range: 0–8 times) per day, to maintain this setting close to the V’e of the patient. No water condensate was found in the water traps. The AHME is adequate for humidification in long-term mechanical ventilation, and eliminates the problem of condensation in the ventilator tubings. The humidification efficiency of AHME is not influenced by the mechanical ventilation mode, provided that the V’e setting of AHME is kept close to the V’e of the patient. Comparison of conventional heated humidification to a new active heat and moisture exchanger in the ICU Crit Care 1999, 3 (suppl 1):P17 Background: Heated humidification (HH) is commonly used with or without a heated wire circuit (HWC) to humidify inspired gases during mechanical ventilation (MV). We compared HH and HH with a HWC to a new active heat and moisture exchanger (AHME). The AHME (Humid Heat, Gibeck, Sweden) consists of a typical HME and a heat and water source delivered between the patient and the HME. The volume of water delivered and heat output are based on a set minute ventilation. A pre-set airway temperature of 37°C is used. Methods: Thirty patients requiring MV for >72 h were studied. Pts received humidification via a HH, HH + HWC (Fisher & Paykel), and AHME in random sequence for 24 h each. All devices were set to deliver 37°C at the proximal airway. During each period of ventilation, the following were measured; airway temperature, min and max body temperature, number of suctioning attempts, volume of secretions, consistency of secretions, number and volume of saline instilled, water usage, condensate, ventilator settings, minute volume, number of circuit disconnections. Water usage was measured by weighing the water bag before and after 24 h use. Consistency of secretions were judged as thin, moderate, or thick as previously described (Suzukawa: Respir Care 1989, 34:976). Condensate was measured by emptying fluid into a graduated container and sputum volume measured by collecting secretions in a Luken’s trap. Airway temperature was measured at the ET tube using a rapid response thermistor. Resistance of the AHME was measured before and after use. Results: There were no differences in any of the variables related to humidification efficiency (secretion volume and consistency, number of suctioning attempts, or volume of saline used). Water usage and volume of condensate were significantly different between devices, but delivered airway temperatures were not. Statistical analysis was done with ANOVA. *P < 0.05, see Table. Water Usage (ml) Condensate (ml) Airway Temp. (°C) Minute volume was similar between groups (11.6 ± 3.3 vs 11.9 ± 3.4 vs 11.8 ± 2.7 l/min) as was bias flow during flow triggering (5.8 ± 2.5 vs 5.4 ± 2.6 vs 5.9 ± 2.3). AHME resistance before and after use was unchanged (1.66 ± 0.11 vs 2.28 ± 0.82 cm H2O/l/s). Conclusion: In this early study, the AHME provided equivalent humidification as HH and HH + HWC with a lower water usage. This occurs because the HME portion of the AHME returns ~32 mgH2O/l, which only requires the active portion to add ~12 mgH2O/l to reach 44 mgH2O/l. Additionally, by placing the AHME between the patient and ventilator circuit, continuous flow from flow triggering systems is not humidified. No other differences were noted. Disadvantages of the AHME include Poster abstracts 9 deadspace (~70 ml), weight on the ET tube and the heat source near the patient. Measured external temperature of the AHME did not exceed 38°C. Further long term studies are required to define the role of the AHME. A new device for 100% humidification of inspired air A Larsson and L Svanborg Department of Anesthesia and Intensive Care Medicine, University Hospital Lund, Sweden and Louis Gibeck AB, Upplands Väsby, Sweden Crit Care 1999, 3 (suppl 1):P18 Introduction. Passive heat/moisture ex-changers (HME) which are based on a hygroscopic condensor principle usually provide adequate humidity (up to 32 mgH2O/l air) of the inspired gas during ventilator treatment [1,2]. However, in about 5–10% of the patients with e.g. thick secretions [1,2] active humidifiers that can provide 100% humidity are needed. These devices cause free water condensation in the tubings [3] with risks of contamination and of compromising the ventilator function. To avoid this a new humidifier has been developed. It consists of a supply unit with a microprocessor and a water pump, and a humidification device, which is placed between the Y-piece and the endotracheal tube. The humidification device is based on a hygroscopic HME, which absorbs the expired heat and moisture and releases it to the inspired gas. External heat and water are then added to the patient side of the HME, so the inspired gas reaches 100% humidity at 37°C (44 mgH2O/l air). The external water is delivered via a pump onto a porous membrane and then evaporated in the inspired air by an electrical heater. The microprocessor controls the water pump and the heater by an algorithm using the minute ventilation (which is fed into the microprocessor) and the airway temperature measured by a sensor mounted in the flex tube on the patient side of the humidification device. The aim of this study was to test the performance of this humidifier at different ventilator settings in a lung model. Methods: The lung model is based on the ISO 9360 International Standard with the exception of that the water-bath temperature is regulated to have a constant temperature of 35.5 ± 0.5°C. The model was ventilated with a Siemens 900 B ventilator set a minute ventilation from 5 to 25 l/min, I:E 1:2, and a rate of 12, 15 or 20/min during 90 min. The moisture content (MC) in the inspired air was calculated from the water delivered (WD) and the loss of water from the lung model (WL): MC = WL– WT + (WD–WH), 45 40 where WT is the water in the tubing between the device and the lung model and WH the water trapped in the HME. WL, WT, WD, and WH were found by weighing before and after the experiment. During the experiment no condensation was found in the flex tube between the device and the lung model. 20 2 3 4 5 6 7 8 Mi9nute Ventilation (l/1m2in) 13 14 15 16 17 18 19 20 10 11 Conclusion: In a lung model, ventilated with 5–25 l/min, the new humidifier gave an absolute humidity of 39–45 g/l, with the lower level at the highest ventilation. Thus, the device had the intended performance characteristics. Modelling the effect of ambient oxygen fraction on hypoxaemia during apnoea Crit Care 1999, 3 (suppl 1):P19 Hypoxaemia during apnoeic oxygenation complicates tests for brainstem death and exposes the patient’s organs to the risk of anoxic damage. This study investigates the effect on hypoxaemia of varying the ambient oxygen fraction during apnoea. Methods and results: The Nottingham Physiology Simulator is a validated simulation of advanced, iterative physiological models [1]. The model was set up as a 70 kg adult with normal physiological values other than: pulmonary venous admixture 20%, alveolar deadspace fraction 20% of tidal volume and functional residual capacity 2 l. The patient’s lungs were ventilated with 100% Critical Care 1999, Vol 3 suppl 1 oxygen for 2 min and the patient was then apnoeic with an open airway exposed to 21, 50, 80 or 100% oxygen. Arterial oxygen and carbon dioxide tensions (PaO2, PaCO2) were recorded continuously until arterial oxygen saturation fell to 50%. The changes in PaO2 and PaCO2 are shown in the figure on the previous page. Obstructive sleep apnea in acute respiratory failure Discussion: Provision of very high ambient oxygen fractions greatly extends the safe duration of apnoea. As oxygen fraction is increased, increasingly large effects are achieved. S Pivetti, F Navone, B Tartaglino, R Urbino and V Gai Medicina d’Urgenza e P.S. Medicina, E.D., Az.Osp. ‘S. Giovanni Battista’ di Torino’, Torino, Italy Crit Care 1999, 3 (suppl 1):P20 Study objectives: Emergency medicine deals with the diagnosis and the prevention of potentially life-threatening events, as well as prevention, diagnosis and treatment of acute illnesses; one of this event is sleep apnea syndrome (SAS). The relationship between obstructive sleep apnea (OSA) and acute respiratory failure (ARF) is not well established. The aim of the study was to evaluate the prevalence of OSA in hypercapnic ARF patients and its correlations with the severity and length of nocturnal arterial oxygen desaturation, diurnal arterial carbon dioxide (PaCO2) and oxygen (PaO2) tensions, diurnal oxygen saturation, sudden death and BMI. Methods: 46 patients with chronic obstructive pulmonary disorder (COPD) (31 men and 15 women; M=68 years; range 36 to 83) with hypercapnic ARF underwent a full night of polysomnography. The polysomnography consisted of continuous polygraphic recording (by Compumedic Sleep PTYLTD Abbotsford) from surface leads for electroencephalography, electrooculography, electromyography and ECG, and from noninvasive sensor for nasal airflow, tracheal sounds, body position, thoracic and abdominal respiratory efforts, and oxymyoglobin level. The number and duration of nocturnal sleep apneas and hypopneas and the consequential oxygen desaturation were evaluated; sleep apnea was defined as more than five episodes of apnea or hypopnea per hour of sleep (apnea/hypopnea index = AHI >5). Furthermore BMI, basal diurnal PaCO2, PaO2 and arterial oxygen saturation were also recorded. Results: Overnight polysomnography was successfully performed in 39 of the 46 studied patients; 4 patients were intolerant to the study and 3 patients were awake all the sleep time. OSA was found in 13 of the 39 ARF patients (33.3%) and the mean AHI was 19.3 events per hour. We found statistically significant correlations between OSA and BMI (P < 0.01; M=38), PaO2 (P < 0.001; M=65), diurnal oxygen saturation (P < 0.001; M=86) and nocturnal oxygen desaturation (P < 0.001; M=80). Conclusion: The overnight polysomnography detects the possible existence of OSA in hypercapnic ARF. We also found a statistical significance positive correlation between OSA and hypoxemia. Polysomnography may be indicated to exclude sleep-induced desaturation contributing to the actual ARF, but it may also improve therapeutic and prevention strategy. Nasal continuous positive airway pressure: do mask pressures reliably reflect intratracheal pressures? Crit Care 1999, 3 (suppl 1):P21 Introduction: Nasal continuous positive airway pressure (nCPAP) increases intrathoracic pressure. This way, it may increase functional residual capacity, improve pulmonary oxygen transfer, and reduce the need for endotracheal intubation in acute respiratory or cardiac failure. However, little is known about the loss of externally applied pressure on its way from mask via pharynx into the trachea. We studied the correlation between mask and intratracheal pressures in 8 surgical ICU-patients. Patients and methods: In 8 postoperative patients after extubation, pressures were measured in nasal mask and trachea (via a catheter, o.d. 0.9 mm) during nCPAP treatment with either 5 or 10 mbar positive pressure (high-flow gas source, 65 l/min, maskpressure adjusted with a PEEP-valve). From the area under the pressure–time curves, absolute pressures, but also the percentage of mask pressure transmitted into the trachea were calculated. Study performed with approval of the committee of medical ethics and informed consent; mean ± SD; t-test, P < 0.05. Poster abstracts 11 Conclusion: NCPAP is an effective noninvasive means to increase airway pressure in postoperative patients after extubation. However, only with mask pressures of 9–10 mbar, but not with 5 mbar, intratracheal pressures will be maintained reliably and continuously positive during the whole respiratory cycle. Effects of mask–ventilator interface elements in a home noninvasive portable ventilator. Study in cold hypercapnic patients A Esquinas, G González, M Del Baño, P Jara, M Rodríguez, F García and A Carrillo Intensive Care Unit, Hospital Morales Meseguer, Murcia. Spain Crit Care 1999, 3 (suppl 1):P22 Noninvasive mechanical ventilation (NIMV) in hypercapnic COLD excacerbations with a home portable ventilator with a single ventilatory tube has some technical considerations. Objective: We analyze influence of elements used in the maskventilator interface in hypercapnic COLD with a NMV: To compare differents 1). Design of filters (A, B, C, D), 2) Nonrebreathing expiratory valve: a) Swisper and b) Plateau exhalation valve 3) Rramp inspiratory time: (0.05, 0.1, 0.5 seg) affect a predetermined level inspiratory positive pressure (IPAP) (15 cmH2O), 2) Hypercapnia (PCO2) control and 3) Subjective responses: a) Dysnea Brog index (low: 2 to 10 high) and psychological dependence at different stages of therapy (low 2 to high 10). Subjects: Twelve hypercapnic COLD stable patients. Material: BiPAP ST-D (Resp, Inc). Facial mask. Results: See Table. Conclusion: Subjective (dysnea Brog index), objective respiratory response (hypercapnia) and level of IPAP pressure applied during IPAP drops pressure from base line/type of filter IPAP: 15 cmH2O PCO2/pH – type of nonrebreathing valve PCO2 mmHg/pH Dysnea Borg index/ramp inspiratory time Dysnea Borg index Psychological score dependence/period NMV were influenced by a specific design of element intercalates at mask–tube–ventilator line. A specific design of these elements as we showed with a home portable single tube ventilator could affect NMV efficacy in hypercapnic COLD exacerbations. Evaluation by volunteers of respirator characteristics in modes used in non-invasive ventilation R Rokyta, P Hora, M Nalos, J Ruzicka, M Matejovic, I Novak and V Sramek ICU, Medical Department I, Charles Uni Hospital Plzen, Alej Svobody 80, CZ-30466 Plzen, Czech Republic Crit Care 1999, 3 (suppl 1):P23 Introduction: We studied the medical personnel’s power of distinction between various types of respirators in CPAP and CPAP+pressure support (PS) modes. Materials and methods: Five blindfolded volunteers (2 ICU doctors and 3 nurses) performed random evaluation (5 point scale, 1 = best) of following respirators: Elema Siemens 300 (ES300), Adult Star 2000 (AS 2000) and Bird 8400 STi. All volunteers were comfortably seated and instructed to breathe freely with the Results: Individual scores and mean values ± SD are listed in Tables 1 and 2. When CPAP and CPAP+PS were tested together significant differences were found within the group (P < 0.05). Generally, CPAP was better tolerated than CPAP+PS. ES 300 and AS 2000 yielded better results than Bird respirator. Conclusion: ICU personnel may easily differentiate between characteristics of ICU respirators. Respirator with best characteristics may then be used for NIV and possibly also for difficult weaning. Acknowledgement: Supported by IGA grant No. 3999-3 Noninvasive positive pressure ventilation (NPPV) in critically ill patients: preliminary experience R Urbino, C Antro, S Pivetti, B Tartaglino, MG Gregoretti, C Bonetto and V Gai U.O.A Medicina d’Urgenza e P.S. Medicina, Azienda Ospedaliera San Giovanni Battista di Torino, Corso Bramante 88, 10126 Torino, Italy Crit Care 1999, 3 (suppl 1):P24 Study objective: To validate the efficacy of NPPV in patients with hypercapnic or hypoxemic acute respiratory failure (ARF) admitted to a Medical Intensive Care Unit. Materials and methods: Thirty-two patients (23M, 9F, mean age 66, range 25–91) received NPPV if they met the following criteria: severe dyspnea at rest, respiratory muscle fatigue, normal mentation, normal upper airways, stable hemodynamic status and, as for hypercapnic ARF, pH <7.35, PaCO2 >45 mmHg, respiratory rate (RR) >25 bpm and, as for hypoxemic ARF, PaO2/FiO2 <200, RR >30 bpm. Eighteen patients (12M, 6F, mean age 68,4, range 50–91) had hypercapnic ARF due to chronic obstructive lung disease (COLD); 7 (6M, 1F, mean age 75, range 73–84 ) had cardiogenic hypercapnic acute pulmonary edema (cAPE); 7 (5M, 2F, mean age 50, range 25–72) had severe pneumonia (SP), 2 with hypercanic ARF. End-points were the following: pH >7.35, RR <24 bpm, VT >7 ml/kg, reduced dyspnea, diminished signs of muscle fatigue, SpO2 >90%. NPPV was considered successful if the patient was not intubated and mechanically ventilated. NPPV was considered unsuccessful if the patient was intubated and mechanically ventilated, became intolerant of mask or died. BiPAP Respironics® ventilators (S/T-D 20, S/T-D 30, Vision), were used to administer NPPV, as pressure support ventilation, by nasal or facial masks. All patients were given standard medical therapy, as required by the underlying disease. Results: NPPV was successful in 14 of 18 COPD patients (77.7%), in all 7 patients with cAPE (100%) and in 3 of 7 patients with SP (42.8%). Failure in 4 COLD patients was due to mask intolerance in three cases and to sudden death in one case. Four patients with SP (three seriously immunocompromised) died. COLD patients were ventilated for 3 to 62 h (mean 21.5 h), cAPE patients for 4 to 15 h (mean 7.4 h) and SP patients for 12 to 148 h (mean 59.7 h). Ventilation was longer in SP patients who obtained a therapeutic benefit (mean 112 h) than in SP patients who did not (mean 23 h). Conclusion: With the limits of this observational study, we conclude that NPPV has been shown to be an effective support therapy for COLD patients with acute exacerbation and for hypercapnic severe cAPE patients. The use of NPPV in patients with SP was less effective and warrants ulterior study to be validated, according to literature. Noninvasive mechanical ventilation in asthma crisis: an alternative ventilatory therapy to endotracheal intubation A Esquinas, D González, A Carrillo, M Del Baño, M Rodríguez, F García and P Jara Intensive Care Unit, Hospital M Meseguer, Murcia, Spain Crit Care 1999, 3 (suppl 1):P25 Oxygen therapy by mask venturi (OMV) in asthma crisis (AC) could not be avoided,, and urgent endotracheal intubation (ETI) is the lifesave procedure recommended. Sometimes in a selected population noninvasive ventilation (NMV) may avoid ETI and his deleterious effects (barotrauma, infections, etc). Objective: We describe our first experience in treatment of acute respiratory insufficiency in (AC). Period of study 1995-98. Setting: Polyvalent ICU. Method: Inclusion criteria: Borg dysnea score: 5 ; respiratory rate: >30 rpm, PaO2 <60 mm Hg ( FIO2 0.5%). ETI: apnoea or unstable breathing pattern, or severe dysnea. Continuous cardiorespiratory monitoring. Results: Time of NMV: 5 ± 3 h levels of IPAP: 12 ± 3 EPAP 6 ± 3 cmH2O; Global respiratory rate: 38 ± 10; pH: 7.36 ± 0.02; pCO2: 45 ± 7 mmHg paO2: 49 ± 26 mmHg. NMV intolerance (12.5%). Complications: NMV group: skin nose lesion n = 3; ETI group: neumothorax n = 2. Poster abstracts 13 Endotracheal intubation Neumothorax n = 2 Conclusion: NMV in asthma crisis refractory to (OMV) is a safe alternative to ETI, and could be avoided in selected patients (50%). Borg Dysnea score index and respiratory rate at 3 h: 38 ± 6 to 25 ± 6 rpm in NMV group are the best early clinical predictors. Noninvasive positive-pressure ventilation in acute respiratory distress syndrome: preliminary results T Principi, S Pantanetti, P Carletti, E Adrario and P Pelaia Department of Medical and Surgical Emergency, University of Ancona Crit Care 1999, 3 (suppl 1):P26 The NIV in acute respiratory failure of a previously healthy lung is not much widespread but much discussed. We report the first data about four patients, who have been accepted in our ICU due to acute respiratory failure post-trauma and treated with ventilatory support via face mask like NIV. All patients were negative to pre-existing lung disease and got thoracic trauma with multiple costal fractures and bony fractures. We used the mechanical ventilator Adult Star (Infrasonic, Inc., San Diego USA). All the patients were co-operating and without neurological deficiency. The NIV has been applied for 2 days and alternated with spontaneous ventilation through Venturi mask after 24 h. Results: the analyzed data show an improvement of PaO2 in all patients, already after the first hours of treatment as well as a respiratory rate reduction. Discussion: The NIV has to be considered as a conventional ventilation’s kind also by acute hypoxemic respiratory failure. The admission’s criteria of the patients to this kind of ventilation is however important. In conclusion, we can affirm that the NIV has an important advantage compared to the conventional ventilation, that is a shorter stays in the intensive care unit, associated to a reduction of pneumonia related to endotracheal intubation. 57.6 ± 11.1 126.9 ± 14.4a 121.7 ± 17.9a 121.7 ± 17.9a 125.4 ± 3.9a 125.4 ± 3.9a 130.7 ± 29.9a 116.2 ± 7.2a 114.7 ± 12.3a 19 ± 1.1a 17.7 ± 0.8a,b ANOVA One Way rep. P < 0.001. Tukey: asignificantly diff. vs. basal; bvs. 1 h. Noninvasive mechanical ventilation (NIMV) in weaning failure: could be an alternative approach? A Esquinas, D González, A Carrillo, M Del Baño, M Rodríguez, F García and P Jara Intensive Care Unit, Hospital Morales Meseguer, Murcia, Spain Crit Care 1999, 3 (suppl 1):P27 Setting: Polyvalent ICU. A trial with noninvasive ventilation (NIMV) could be a safe alternative option in some selected unweanneable patient, after a period of invasive approach of weaning with: 1) Endotracheal tube (ET) or 2) Traqueostomizated with a ‘T’ oxygen or Pressure Support Ventilation (PSV) trials. Subjects: We show a cases series where NIMV have been applied as an alternative weaning technique in three difference clinical situations of unweanneability: 1) Post-extubation failure n = 12, 2) Decanulation in traqueostomizated n = 1, and 3) Elective extubation n = 3. Methods: Inclusion criteria: acute respiratory insufficiency in a period (0–48 h): respiratory rate >30 rpm, increase accessory respiratory muscular activity, hypoxemia PaO2 <60 mmHg at mask venturi (FIO2: 0.5) after a period of ‘T’ piece or PSV and almost four consecutive weaning failure trials. Excluded: hemodynamic instability (SAT <90 mmHg), uncooperative patients, and excessive secretions., IPAP/EPAP cmH O to achieve: >10 ml/Kr and 2 decrease in dysnea Borg score. Continuous cardiorespiratory monitoring. Results: Unweanneable population n = 16. Average age: 61 ± 20, male n = 12; APACHE II score: 21 ± 3, time of NIMV: 72 ± 12 h. Postextubation – NMV Decanulation – NIMV Extubation – NIMV n = 12 n = 1 n = 3 n = 16 NIMV was effective in reduce dysnea Borg scores (4 to 2), gasometric alterations and avoid reintubation 8/12. Causes of exclusion: secretions 23%, hemodynamic instability 15%. Complications: skin lesion n = 2, gastric distension n = 1. Conclusion: 1). A trial with a NMV as a weaning alternative technique is a safe alternative in selected patients with showed a persistent weaning failure. 2). Reduction in ICU stay, mortality, with a great comfort and few complications compare to others method. Airway pressure release ventilation (APRV) enhances cardiac performance in patients with acute lung injury (ALI)/adult respiratory distress syndrome (ARDS) LJ Kaplan, H Bailey and V Formosa** Medical College of PA-Hahnemann University, Departments of Surgery, *Emergency Medicine, **Pulmonary Medicine 3300 Henry Avenue, Philadelphia, PA 19129, USA. Tel:(215) 842-7558; Fax; (215) 843-1095; E-mail: Crit Care 1999, 3 (suppl 1):P28 Purpose: To determine whether APRV can safely enhance hemodynamics in patients with ALI/ARDS. Methods: Patients with ALI/ARDS were ventilated in pressure control (PCV) with both upper and lower inflection points eliminated from the hysteresis curve; all patients had a pulmonary artery catheter. Ventilator settings achieved a pCO2 of 35–45 torr and a pO2 of >60 torr. Patients were then changed to APRV. Data included: age, diagnosis, ventilator settings, hemodynamic profiles, ABG, lactate, and medications. Data (means ± SD) were compared using a Student’s t-test; significance assumed for P < 0.05. Results: Mean age was 58 ± 9 years (n = 12) and mean Lung Injury Score was 7.6 ± 2.1. Temperature (PCV 100.8+1 v APRV 100.6+1F; P > 0.5) and PaO2/FIO2 (PCV 168 ± 24 v APRV 182 ± 18; P > 0.05) were similar. Diagnoses were pneumonia (22%), abdominal sepsis (45%), trauma (33%), bacteremia (18%) and transfusion related lung injury (1%). Peak airway pressures fell from 38 ± 3 (PCV) to 25 ± 3 cmH O (APRV, P < 0.05); mean pressures fell from 18 ± 3 2 (PCV) to 12 ± 2 cmH O (APRV; P > 0.05). Paralytic use (PCV 74% 2 v APRV 4%; P < 0.05) and sedative use significantly declined (PCV 100% v. APRV 68%, P < 0.05). Pressor use decreased substantially (PCV 92% v ARPV 45%, P < 0.05). Lactate levels remained unchanged (PCV 2.2 ± 0.6 v APRV 1.8 ± 0.8 mmol/l; P > 0.05). Cardiac index rose from 3.2 ± 0.4 (PCV) to 4.6 ± 0.3 l/min/m2 BSA (APRV; P < 0.05) while DO2I increased by 36% (P < 0.05). CVP declined from 18 ± 4 (PCV) to 12 ± 5 cmH O 2 (APRV; P > 0.05). Conclusion: APRV may be used safely in patients with ALI/ARDS and decreases the need for paralysis and sedation compared to PCV. APRV increases cardiac performance with decreased pressor use and CVP in patients with ALI/ARDS. Further study of ARPV is warranted to discover its impact on resource utilization and patient outcome. Pulmonary function in children who were on long-term mechanical ventilation due to neonatal respiratory disease I Vidmar, J Primozic, S Grobovsek Opara and M Grasselli University Medical Centre, Division for Paediatric Surgery and Intensive Care, Zaloska 7, SI-1525 Ljubljana, Slovenia Crit Care 1999, 3 (suppl 1):P29 Context: Children with a history of neonatal respiratory disease that required mechanical ventilation, who develop subsequent bronchopulmonary dysplasia, often have abnormal pulmonary function. The extent to which the neonatal respiratory disease alone is involved is not clear. Objective: To evaluate the association between neonatal respiratory disease without bronchopulmonary dysplasia on discharge and pulmonary function later in childhood. Design: Case–control study. Setting: Ambulatory follow-up of former intensive care patients at a university medical centre. Poster abstracts 15 Table. Pulmonary function tests: mean ± standard deviation VC (n = 18) ml *Significant difference (P < 0.01) FEV1 (n = 18) ml DLCO (n = 18) (mmol/min)/kPa Rt (n = 16) kPa/l/s TGV (n = 15) ml Participants: Eighteen children aged 11–15 years with a history of neonatal respiratory disease were randomly recruited, regardless of gestational age or cause of disease. Inclusion criteria: mechanical ventilation for >14 days; high inspired oxygen fraction for >2 days (FiO2 >0.4). Exclusion criteria: presence of bronchopulmonary dysplasia or other acute or chronic pulmonary disease at the time of this investigation. Eighteen controls matched for age, sex and height were recruited from children of the hospital staff. All were healthy at birth and had no pulmonary disease at the time of this investigation. All parents gave informed consent. Pulmonary function tests: Vital capacity (VC); forced expiratory volume in the first second (FEV1) with and without challenge by the bronchoconstrictor methacholine; diffusing capacity (DLCO); airway resistance (Rt) with and without methacholine challenge; and thoracic gas volume (TGV). Main outcome measures: Variables of pulmonary function in the cases. Differences between the cases and controls were compared using the paired-sample t-test. Results: Both FEV1 and Rt differed significantly (P < 0.01) between children who had had respiratory disease as neonates (cases) and controls. There were no significant differences in VC, DLCO and TGV (Table). Differences in VC and FEV1 between cases and controls after methacholine challenge were not significant; however, this analysis is of limited value because only eight or nine matched pairs underwent these tests. Conclusion: A mild degree of airway obstruction is apparent in children 11 to 15 years after neonatal respiratory disease, even in the absence of bronchopulmonary dysplasia or other pulmonary disease. Does the size of the ventilator tidal volume affect the incidence of post operative pneumonia? SK Appavu, TR Haley, A Khorasani and SR Patel Division of Surgical Critical care, Cook County Hospital and the Department of Surgery, University of Illinois College of Medicine, Chicago, Illinois, USA Crit Care 1999, 3 (suppl 1):P30 After major abdominal or thoracic surgery, the patient may develop rapid shallow ventilation because of splinting, pain or heavy sedation. This may lead to the development of post operative atelectasis and pneumonia. Hence, it seems reasonable to expect that the administration of large tidal volumes (VT) during post operative mechanical ventilation will prevent or decrease the incidence of post operative pulmonary complications including that of pneumonia. Whether or not this is true is yet to be determined. Therefore, we performed the following prospective study. We hypothesized that large VT mechanical ventilation after major operations resulted in a lower incidence of post operative pneumonia. Adults admitted to the surgical intensive care unit for post operative mechanical ventilation after major abdominal or thoracic surgery were placed on one of two VT regimens: 9 ml/kg (group 1) or 14 ml/kg up to a maximum of 1000 ml (group 2). Patients who were not placed on the correct VT regimen and those whose tidal volumes were changed during the study were excluded. Standard ICU monitoring was instituted. In addition, ventilator performance, peak inspiratory pressures, blood gases and daily chest Xrays were monitored. The incidence of post operative pneumonia was recorded. Results were analyzed by SPSS statistical software. Results: Forty-nine patients completed the study, 29 in group 1 and 20 in group 2. Their mean age was 52.7 years. There were 28 males and 21 females. Thirteen of 49 patients (26.5%) developed post operative pneumonia. A comparison of the two groups is shown below: Females VT (ml) vent (h) Pneumonia Conclusion: Post operative ventilation with large tidal volumes does not reduce the incidence of pneumonia. Bronchoscopy and BAL in mechanically ventilated patients in an ICU at a university teaching hospital R Strauss, M Sander, A Müller, M Wehler, C Ernst and EG Hahn Department of Medicine I, University Erlangen–Nuremberg, Krankenhausstr. 12, D-91054 Erlangen/Germany. Tel: 0049-9131-8533885 Fax: 8536909; E-mail: Crit Care 1999, 3 (suppl 1):P31 Introduction: Bronchoscopy is an important diagnostic and therapeutic tool in modern intensive care medicine. In ventilated patients it can lead to hemodynamic instability and can compromise the gas exchange . Method: We evaluated in a prospective study from 3/1997 to 9/1998 indications, complications and side effects of bronchoscopy in a 12 bed medical ICU. The vital signs of the patients were monitored continuously by ECG, invasive blood pressure and SaO2 measurement. A BGA was performed 5 min before and 5/30/120 min after the examination. Results: One hundred and fifty-one bronchoscopies were performed in 103 patients (63 male, median age 60 years, median APACHE II-Score 27.5). The indications were bacteriological examinations in 113/151 (75%), respiratory toilet in 29/151 (19%), oxygenation problems in 11/151 (7%). Less common indications were atelectasis, intubation and biopsy. A BAL was performed in 111/151 (74%) cases. The median PaO2/FiO2-ratio (PFR) was 292 mmHg 5 min before bronchoscopy and 254/182/193 mmHg 5/30/120 min afterwards. In the subgroup with BAL the median PFR was 295 mmHg 5 min before, 5/30/120 min after examination 261/181/194 mmHg. The PFR was in the critical range <80 mmHg before bronchoscopy in 5/151 (3%) and 5/30/120 min after the examination in 5/151 (3%), 9/151 (6%) and 7/151 (5%) cases. In patients with BAL the corresponding figures were 2/111 before and 3/111, 6/111, 4/111 after bronchoscopy. A decrease of the PFR between the beginning and 30 min after finishing bronchoscopy by more than 50 mmHg was observed in 59/151 (39%) cases for all patients, in 50/111 (45%) for the BAL subgroup. During 5/151 (3%) procedures serious complications were observed. An increase of the blood pressure (215/120 mmHg max.) after local application of noradrenalin and a high peak pressure during ventilation (>45 Torr) did not need therapy. A tachyarrhythmia absoluta was treated by cardioversion. A decrease of systolic arterial blood pressure (min. 67 mmHg) during sedation, could be stabilised by volume substitution and dopamine infusion. Bundle-branch block like ventricular complexes were observed on the ECG monitor in one case, which were accompanied by a blood pressure decrease. After an interruption the ECG showed sinus rhythm and the hemodynamic stabilised again. In a 24 h period after bronchoscopy the patient died because of an acute myocardial infarction. Conclusion: Bronchoscopy is a safe procedure in critical ill mechanically ventilated patients. Even in patients with BAL, in the most cases only a slight decrease of the PFR could be observed. The lowest PFRs were observed 30 min after bronchoscopy, 90 min later the PFR was almost back to the starting level. Critical PaO2 values were only seen in rare cases. Complications could be handled in all cases. The death of one patient in a 24 h range after bronchoscopy was probably caused by the underlying disease and is to be seen only in temporal coincidence. Clinical presentation and prognostic factors in fat embolism syndrome GD Puri, VK Arya and P Chari Department of Anaesthesiology and Intensive Care, Post Graduate Institute of Medical Education and Research, Sector 12, Chandigarh, 160012 Crit Care 1999, 3 (suppl 1):P32 Fat embolism occurs in most of the patients following long bone fractures but 1–5% of these present clinically as fat embolism syndrome. The recorded data of 64 patients having uncomplicated long bone fractures without head and chest injuries admitted to our ICU with diagnosis of FES over a period of 3 years was evaluated to determine factors effecting management and prognosis. Forty-two patients belonged to subacute and 29 to fulminant FES group depending upon their clinical status at the time of ICU admission. Majority of FES patient had fracture femur and presented with respiratory distress as initial symptom. Lung injury score was 1.34 ± 0.64 in subacute and 3.36 ± 0.44 in fulminant group (P < 0.01). Patients with fulminant FES had more number of abnormal laboratory parameters. Eighteen patients (43%) in subacute and all patients in fulminant group required ventilation. There was significant delay from FES presentation to ICU admission for subacute FES patients requiring ventilatory support than the patients improving with conservative therapy alone (P < 0.05). One patient in subacute (2.3%) and 10 patients in fulminant FES group (45.5%) died. The compliance of respiratory system (Crs) at the start of intermittent positive pressure ventilation was significantly less in fulminant as compared to subacute FES patients (P < 0.05). Most of the ventilated patients had initial improvement in Crs with ventilation but only those patients who made continuous improvement in Crs beyond 48 h of ventilation ultimately maintained oxygenation and survived in both the groups. We conclude that early ICU admission and supportive therapy is important determinant of morbidity in FES. Patients with more number of abnormal laboratory parameters and those in whom Crs and oygenation index does not improve even after 48 h of adequate ventilatory support are unlikely to improve by conventional ventilatory support alone and need to be shifted to other modalities of maintaining oxygenation. Acute respiratory distress syndrome in a University Hospital ICU in Japan High-frequency oscillatory ventilation (HFOV) in bronchiolitis patients H Yukioka and K Nakatani* Division of Critical Care Medicine and *Department of Anesthesiology and Intensive Care Medicine, Osaka City University Medical School, 1-5-7 Asahi-machi, Abeno-ku, Osaka 545-8586, Japan Crit Care 1999, 3 (suppl 1):P33 Objective: To determine prognostic factors for and the outcome of acute respiratory distress syndrome (ARDS) in our ICU. Method: The American–European consensus conference definition [1] was used for ARDS diagnosis. Thirty-three (2.1%) of 1588 patients admitted to the ICU met the criteria for ARDS. Mechanical ventilation with PEEP was performed for all patients with ARDS. Steroid pulse therapy (60%), nitric oxide inhalation (21%), surfactant replacement (9%), and neutrophil elastase inhibitor administration (24%) were also used. For determination of prognostic factors of ARDS, mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), and multiple organ dysfunction score (MODS) [2] excluding the Glasgow Coma Score were measured and compared with outcome. Results: There were 22 men and 11 women aged 61 ± 12 years. The mortality rate of ARDS was 73%. Sepsis was the main cause of ARDS accounting for 73% of cases. All ARDS patients with septic shock (n = 9) and with sterile shock [3] (n = 4) died. The patients with shock had higher MODS compared to those without shock with mortality rate 55%. There were no significant differences in mPAP and PVR between survivor and nonsurvivors. ARDS patients who had high MODS, especially those with low PaO2/FIO2 and high pressure-adjusted heart rate, 5 days after the onset of ARDS had a poor prognosis. Conclusion: Shock and MODS, but not pulmonary hypertension, are important as prognostic factors for ARDS. ELIM Duval*, AJ van Vught*, PLJM Leroy*† and RJBJ Gemke* *Ped. Int. Care Unit, Wilhelmina Kinderziekenhuis,PO Box 18009, 3501 CA Utrecht, The Netherlands and †Department of Pediatrics, University Hospital Ghent, Belgium Crit Care 1999, 3 (suppl 1):P34 Respiratory syncytial virus (RSV) is nowadays the leading cause of bronchiolitis and viral pneumonia in children. Although the course is often benign, some children need prolonged hospitalisation and mechanical ventilation or even ECMO if conventional mechanical ventilation (CMV) fails. HFOV is currently considered to be contraindicated in obstructive airway disease with prolonged time constants due to the risk of dynamic airtrapping. This could give rise to circulatory and ventilatory compromise and barotrauma. Nevertheless, bronchiolitis patients are sometimes put on HFOV after deterioration on CMV. We report 9 patients with RSV bronchiolitis and pulmonary overdistention (small airway disease) successfully treated with HFOV after deterioration on CMV. Although marked hyperinflation was present in all our patients prior to transition, no airleaks developed during HFOV. In one patient the oxygenation index (OI) increased after start of HFOV. Nitric oxide was added and oxygenation improved immediately. All patients survived without residual lung disease. In distinct to current opinion, we showed that small airway disease can safely and successfully be managed with HFOV. Ventilatory strategy should be directed to open up the small airways and keep them open with sufficiently high mean airway pressures (‘the open airway strategy’ similar to the ‘open lung strategy’ in diffuse alveolar disease). Permissive hypercapnia may be used to reduce pressure swings as much as possible, leading to less shear stress on lung tissue, without influencing airway recruitment. Further dynamic airtrapping can be prevented with the use of longer expiratory than inspiratory times and with prevention of spontaneous breathing. An increasing OI at 48 h may be an indicator of failure of HFOV and alternative treatments should be considered. NO might be such an option to avoid ECMO. The importance of prone position ventilation in ARDS for the improvement of oxygenation index J-C Lewejohann, H-J Düpree, J Gleiß, S Lewejohann, E Muhl and H-P Bruch Med. Univ. of Luebeck, Dept. of Surgery, Ratzeburger Allee 160, 23538 Luebeck, Germany. E-mail: Crit Care 1999, 3 (suppl 1):P35 Introduction: In acute respiratory distress syndrome (ARDS) change from supine (SP) to prone position can improve gas exchange by recruiting alveoli situated in dorsal dependent regions and by alteration of ventilation/perfusion ratio. The aim of this study was to investigate the effect of prone position (PP) after application of high fractional inspired oxygen (hFiO2), inverse ratio ventilation (IRV), positive end exspiratory pressure (PEEP) as well as kinetic therapy (KT) and hemofiltration (HF) did not lead to a breakthrough in treatment of severe ARDS. Methods: We studied 22 consecutive patients with severe ARDS (mean age 64 ± 11.16 [SE] years) in a clinical follow-up design. All patients received hFiO2, IRV and PEEP before starting prone position, while 15 obtained HF (Prisma®, Hospal) and 3 KT (Rotorest®). Prone position was commenced 82 h median time (range 6 to 417 h) after onset of severe ARDS at a mean PaO2/FiO2 ratio of 98.02 ± 6.11 (SEM) mmHg. We compared individual oxygenation index (PaO2/FiO2) before and after start of prone position with linear regression analysis (Excel® regression-procedure; SPSS® T-test). Results: In the stage of supine position neither treatment with hFiO2, IRV, PEEP nor HF and KT led to an improvement of oxygenation index. After starting prone position ventilation 20 of 22 patients showed a significant increase of the oxygenation index (responder: Y[SP] = [–46.11 ± 3.41] × X + [194.03 ± 3.78]; Y[PP] = [25.00 ± 3.05] × X + [170.36 ± 2.68]; [mean ± SEM]; P < 0.05), while 2 patients showed no improvement of oxygenation index (slope of regression SP/PP: 42.96/–22.70 and –11.63/–19.33). Renal failure of these two non-responders was not treated by HF. Improvement of oxygenation index was independent of duration in supine before the begin prone position (range 6 to 417 h). In one patient PP was started actually after 417 h of treatment at our Intensive Care Unit. Conclusion: Starting prone position seems to mark a U-turn for oxygenation for the majority of patients with severe ARDS, while application of high fractional inspired oxygen, inverse ratio ventilation, positive end exspiratory pressure as well as kinetic therapy and hemofiltration do not necessarily improve oxygenation. The timing of this non invasive technique primarily depends on the decision to turn the patient from supine to prone. We recommend prone position in ARDS as soon as possible to reduce lung injury and complications resulting of mechanical ventilation. The effect of the pulmonary time constant on the cough peak flow rate at two different inflation pressures: a bench test model JS Wills and RP Mahajan University Department of Anaesthesia and Intensive Care, Queen’s Medical Centre, Nottingham NG7 2UH, UK Crit Care 1999, 3 (suppl 1):P36 Supramaximal flow is characteristic of the cough manoeuvre and is thought to be the result of dynamic compression of collapsible airways. We investigated the effect of changing the pulmonary time constant on the peak flow rate produced by an in vitro cough manoeuvre. We used a prototype artificial cough generator and a simplified lung-airway model. The model consisted of a compliant bag with a resistor (internal diameter 3 mm to 7 mm) that emptied through a collapsible tube. The resulting range of emptying time constants (420 to 2800 ms) included those found in vivo (500 to 2000 ms). The lung-airway model was inflated to one of two pressures (31 cmH O or 55 cmH2O) and then compressed within a 2 glass container to a pressure of 45 cmH2O. A mechanically-operated glottis opened rapidly and the resultant flow was measured by a pneumotachograph. The cough peak flow rate (CPFR) was Time constant (ms) 420 recorded for 20 cough manoeuvres for each configuration and the values of the mean and standard deviation are shown in the Table. The results from this bench-test model suggest that the pulmonary time constant has a profound effect on the magnitude of the cough peak flow rate. Computer simulation: a guideline in ventilator setting in severe lung disease L Uttman, S Sigurdsson and B Jonson Departments of Clinical Physiology and Anaesthesiology, University Hospital, Lund, Sweden Crit Care 1999, 3 (suppl 1):P37 Mechanics and gas exchange can in be studied with a computercontrolled ventilator. The physiological profile obtained describes the Pel/V diagram, inspiratory and expiratory resistance versus volume and the expired volume of CO2 versus tidal volume. When setting PEEP, frequency, I:E ratio, and minute ventilation or inspiratory pressure the physician needs to assimilate the information of the physiological profile and all clinical information to assure an adequate gas exchange at a non-traumatic ventilation. In ALI/ARDS harm can be caused both by ventilation at too low lung volumes and by ventilation at high volumes. In COPD the task is to ventilate at the lowest possible volume and airway pressure. The complexity of the physiology and ventilator settings makes it impossible to figure out what is the ideal pattern of ventilation in order to reach the immediate therapeutic goals defined by the physician. However, on the basis of an adequate mathematical physiological profile, a computer can by simulation prognosticate what would be the consequences of alternative modes of ventilation. Through repeated simulations the physician can search a mode of ventilation that leads to his goals. Computer simulation can be used to: a) increase the understanding of various patterns of ventilation in disease. b) predict the consequences of alternative settings in a particular patient. In left diagram the total pressure in the ventilator (Pvent), the tracheal pressure (Ptr) and the alveolar, i.e. the elastic pressure, Pel, Poster abstracts 19 Current ventilator setting Alternative ventilator setting 60 O 2 H m40 c , P20 is shown for a patient with critical obstructive lung disease. Under current setting (volume control 10 l/min, Ti = 25%, Tpause = 10%, RR = 16, PEEP = 4 cmH2O) the PaCO2 of 9.2 kPa was deemed acceptable. The pressures were, however, very high. By repeated simulations it was possible to identify a setting which dramatically would reduce the pressures without changing PaCO2. Clinical evaluation of a new closed loop ventilation mode: adaptive supportive ventilation (ASV) RS Campbell, RP Sinamban, JA Johannigman, FA Luchette, SB Frame, KDavis Jr and RD Branson University of Cincinnati College of Medicine, Cincinnati, OH 45267-0558, USA Crit Care 1999, 3 (suppl 1):P38 Introduction: ASV (Galileo, Hamilton Medical, Inc.) is a mode of mechanical ventilation (MV) with a closed loop algorithm to determine and adjust ventilator settings. ASV may adjust mandatory breath rate, I:E ratio, and inspiratory pressure of mandatory breaths. Target minute ventilation (VE) is determined by ideal body weight (IBW) and clinician selected Percent Vent (% Min Vol). Galileo assesses the pt by measuring dynamic compliance and expiratory time constant. With IBW and %Min Vol settings, optimal settings for rate, Ti, VT, and VE are determined. We compared MV with ASV to MV with physician determined vent settings during the initiation of MV. Methods: Ninteen post-operative pts requiring MV were studied. Vent settings by physician were noted and each pt was placed on those settings or ASV randomly. IBW was determined from standardized tables and %MinVol was set to 100%. PEEP and FiO2 were determined by staff and held constant. ABG’s and cardiopulmonary variables (f, VT, VE, Ti, PIP, Paw, HR, MAP, and VCO2) were measured and recorded after 30 min on each mode. Data were compared using student’s t-test. Results: 19 pts (14 male) were studied. Initial ‘test breaths’ during ASV were well tolerated. Mean IBW was 88.8 Kg. Mean age was 54.3 years. Table 1 reveals set and measured ventilator parameters for both study periods. PIP and VT were lower during ASV. Respiratory rate was higher during ASV. VE, TI, and Paw were unchanged between study periods. Mean values for PEEP and FiO2 were 7.3 and 0.48, respectively. Table 2 reveals ABG measurements, CO2 production, and VD/VT ratio. There were no clinically relevant differences in ABG’s or VCO2 between study periods. VD/VT was lower during ASV. No pt suffered any adverse events from derangements in ventilation or acid-base balance. One pt with ARDS receiving 17 cmH O PEEP was hypoxemic during ASV 2 (PaO2 57.2). Table 3 reveals heart rate and mean arterial pressure during each study period. There were no clinical changes to any measured vital sign between the two study periods. Discussion/conclusion: Upon initiation of mechanical ventilation, the precise VE requirement of the pt may not be known. CliniPIP (cmH2O) Paw (cmH2O) PaCO2 (mmHg) PaO2 (mmHg) VCO2 (ml/min) cians use rough estimates and clinical experience to determine VE, respiratory rate, VT, and Ti. Determination of vent settings made by the machine have been suggested (Intern Care Med 1996, 22:199). Our results suggest that ASV as startup mode of ventilation is acceptable and comparable to physician determined ventilator settings. Gas exchange during ASV is equivalent to physician determined ventilation. VT during ASV is more consistent with ‘lung protective’ strategy (7.8 ml/kg) than was conventional VT (9.7 ml/kg). Mechanical ventilation with ASV is more efficient as evidenced by lower VD/VT and may be safer as a result of lower VT and PIP. Poster abstracts 111 catecholamines used were recorded. Blood samples were centrifugated and sera stored at –20°C. Levels of protein S100 were measured using a commercial immunoluminometric assay (Sangtec 100®, Byk Sangtec Diagnostica, Dietzenbach, Germany) according to the guidelines of the manufacturer. Reference level was <0.3 mg/l. Cerebral recovery was evaluated by the five-point cerebral performance category (CPC) on ICU demisson [1]. Results: Mean age was 66 yrs, median 67, range 35–78 years, 9/17 (65%) were male. 14/17 (82%) survived and were evaluated by the CPC. 5/13 (38%) met Category 1 criteria (conscious and alert/normal function), 2 met CPC 2 (conscious and alert/moderate disability, 2 met CPC 3 (conscious with severe disability), 4 met CPC 4 (comatose), 1 met CPC 5 (brain death). In 16/17 patients an elevated S100 was measured with a mean value of 5.13 mg/l, range 0.5–15.4, median 3.8 mg/l, with a maximum 1 h after CPR in 13/16 patients. In all patients of category 1 normal or slightly elevated levels (0.1–0.7 mg/l) were found, returning to normal within a few hours. In category C the highest S100 values (8.8/12.1 mg/l) of surviving patients were found, in contrast to category D with moderate elevated levels (1.7–5.4 mg/l). Patients who died had S100 values of 4.7–15.4 mg/l. No correlation was seen between pH, base excess, serum lactate on admission, catecholamine dosis needed during CPR and neurological outcome. Conclusion: S100 seems to be a sensitive marker of cerebral injury due to diffuse hypoxia after CPR. Normal S100 values excluded severe cerebral damage. Normal or slightly elevated levels of S100 (£0.7 mg/l) are correlated with good neurological outcome, but high S100 values do not necessarily predict an unfavourable prognosis. S Leonard, ADJ Watts, K Parmar*, J Wendon† and B Hunt* Dept. of Anaesthesia and †Liver Failure Unit King’s College Hospital and *Dept. of Haematology, St Thomas Hospital, London, UK Crit Care 1999, 3 (suppl 1):P223 Introduction: Encephalopathy and irreversible cerebral injury may occur in ALF. S100 is a CNS-specific protein that is a marker of cerebral injury [1,2]. We investigated S100 protein in patients with ALF who underwent OLT. Methods: After IRB approval blood samples were taken in 10 patients age 20–51 years with ALF. Blood was taken before OLT (A), during the anhepatic phase (B), 30 min after reperfusion (C), and on days 1 (D) and 4 (E) post-OLT. The blood was centrifuged and serum stored at –70°C. S100 was analysed using an immunoluminometric assay. Results: Serum S100 (X ± SEM) was elevated prior to OLT (normal <0.12 mg/l). By day 4 post-OLT S100 had fallen in all patients except one. This patient subsequently died. Conclusion: Serum S100 is elevated in ALF and encephalopathy. We observed a rise in S100 during OLT in these patients. The role of S100 as a marker of neuronal injury in ALF and OLT warrants further investigation. P224 S100: a potential marker of cerebral trauma M Simenacz and M Vucevic Academic Unit of Anaesthesia, The General Infirmary at Leeds, Great George Street, Leeds, LS1 3EX, UK Crit Care 1999, 3 (suppl 1):P224 Introduction: Head injuries are associated with a high level of morbidity and mortality. The aim of this study was to examine if S100, a calcium binding protein localised in astroglial cells of the central nervous system, can be used as a marker of head injury and to predict survival outcomes from severe head injury. Methods: After informed consent and local ethics approval, 12 severe head injured patients (GCS £8) were included. All patients were treated according to standardised head injury protocols. Serial serum samples were taken over a period of 48 h together with various other physiologic measurements. Plasma concentrations of S100 were analysed using a radioimmunometric assay — Sangtec®S100IMRA. Results: The mean S100 in patients who survived was 1.1 mg/l and in those who died 0.79 mg/l. Six of the 12 patients in the study died. Serum S100 (mg/l) after severe head injury Time after admission (h) Conclusion: Plasma S100 concentrations increase in severe head injuries. The reference value is less than 0.2 mg/l and this was exceeded in both patients who survived and those who died. Serum S100 levels could not be correlated with mortality. M Pugh, K Bresland and M Vucevic Academic Unit of Anaesthesia, Leeds General Infirmary, Leeds, LS1 3EX, UK Crit Care 1999, 3 (suppl 1):P225 Aims of study: A retrospective review of the treatment and outcome of neurosurgical patients admitted to the ICU in the years 1990 and 1996 to assess the effect of the introduction of the routine use of percutaneous tracheostomy and vasoconstrictor therapy. Results: See Table. Discussion: The use of tracheostomies and vasoconstrictors has increased during this period of study. Tracheostomy has no effect on mortality whereas vasoconstrictor usage appears to result in an increase in mortality. Total patients admitted Mean age (years) Tracheostomies performed (%) Days until tracheostomy Use of vasoconstriction (%) Logistic regression on mortality (odds ratio): Exp (B) = 0.76 Exp (B) = 5.46 95% CI (0.40–1.46) 95% CI (2.87–10.41) L Bargues, JP Ducourau, P Morizet, G Boussignac and JM Saïssy Service Anesthésie-Réanimation, HIA BEGIN, Saint Mandé, France Crit Care 1999, 3 (suppl 1):P226 Introduction: During experimental cardiac arrrest, precordial compression associated to the unique use for ventilation of constant flow insufflation of air at the distal end of a modified endotracheal tube provided the same ventilatory results but better hemodynamic effects than manual ventilation [1]. Because of these results and the simplicity of the technique, a study concerning humans beings and using oxygen during cardiopulmonary resuscitation (CPR) has been realized. Methods: After ethic committee approval, adult out-of-hospital cardiac arrests (shocked arrests excluded) were randomized in two groups: control group (C) treated by conventional CPR with active compression-decompression (ACD) and manual ventilation after intubation, Constant Flow Insufflation group (CFI-CPR) treated with ACD and flow rate of 15 l/min through small capillaries of Boussignac tube (Vygon, Ecouen, France). CPR continued for 30 min at the most. As soon as spontaneous circulation returned (SCR), arterial gazometry was made and all patients were mechanically ventilated. Statistical analysis was performed by c2 and Mann-Whitney tests. A P < 0.05 was considered statistically significant. Results were expressed as mean ± SD. Results: Thirty patients were included in C group, 34 in CFI-CPR group. There were no differences in mean age (65 ± 3 vs 62 ± 3 years) or delayed CPR activation (6 ± 2 vs 7 ± 3 min). SCR was observed in 8 patients of C group after 13 ± 6 min and in 6 patients of CFI-CPR group after 14 ± 6 min (NS). The results of arterial gazometries for both group are shown in the Table. Poster abstracts 113 CFI-CPR 6.86 ± 0.08 103 ± 18 237 ± 80 18.2 ± 2.4 95 ± 3 14.2 ± 1.5 92 ± 3 Arterial gazometry, no statistically differences Conclusion: Comparable values of arterial gazometry were observed after CFI-CPR or standard CPR. This easier technique is as efficient as manual ventilation in terms of oxygenation during the early phase of cardiac arrest. Further studies are required to determine if CFI-CPR improve prognosis. P227 Airway management during cardiopulmonary resuscitation (CPR) by training nurses V Dörges, H Ocker, C Sauer and P Schmucker Department of Anaesthesiology, University Hospital of Lübeck, Ratzeburger Allee 160, D-23562 Lübeck, Germany. Tel: +49 451/500-4057; Fax: +49 4509/71068; E-mail: Crit Care 1999, 3 (suppl 1):P227 A experimental model of a patient was designed to grade the success of ventilation using the Guedel airway/face mask (GA/FM), Laryngeal mask (LM) or Combitube (CT) in CPR. It consisted of a manikin head, training lung (Dräger®: compliance 50 ml/cmH2O, resistance 16 cmH2O/l/sec), lower esophagial sphincter pressure (LESP) 7 cmH O and a simulated stomach [1]. 2 Sixteen training nurses were shown the correct use of each device. The volunteers than used each device for a 2-min ventilation. For a successful ventilation a tidal lung volume of >200 mls had to be achieved within 180 s. Peak pressures in the esophagus, lung and gastric 2-min volumes were recorded. Each volunteer was graded from 1 (excellent) to 4 (bad), on the success of airway insertion, quality of the seal and visible adequacy of ventilation. The volunteers could deliver an adequate tidal lung volume with the GA/FM in 7–102 s (median: 24 s); LM in 18–92 s (median: 37 s), and 46–180 s (median: 74 s) with the CT. In the GA/FM group there were three failures, and two in the CT group. Analysis of the success of airway insertion, sealing and adequacy of ventilation shows a significant advantage with the LM or CT (P < 0.0001) against the GA/FM. There was no difference between the LM and CT. The 2-min lung volume delivered with the GA/FM ranged from 4.2–13.4 l (mean: 8.0 l), with peak LESP of 9–27 cmH2O (mean: 16.4 cmH2O) causing a gastric inflation of 2.5–13.6 l (mean: 6.6 l). The 2-min lung volume with the LM was 11.7–44.1 l (mean: 25 l), peak LESP of 0–22 cmH O (mean: 7.9 cmH2O) and gastric 2 inflation of 0–6.2 l (mean: 1.4 l). For the CT the 2-minute lung volume ranged from 12.3–41.5 l (mean: 27 l), peak LESP of 0 and without gastric inflation. Our results show the significant risk of gastric distension when using the GA/FM. Adequate lung ventilation of >5 l/min delivered with the GA/FM could be achieved only by 4 volunteers. The LM might provide the best alternative for airway management during CPR by nursing staff with a 100% success rate on adequacy of ventilation. A training program on the LM might further reduce the risk of gastric inflation. P228 Does emergency transportation induce a stress-response in probationers V Doerges, S Dix, H Ocker, A Kühl and P Schmucker Department of Anaesthesiology, University Hospital of Lübeck, Ratzeburger Allee 160, D-23562 Lübeck, Germany Crit Care 1999, 3 (suppl 1):P228 Introduction: Common opinion is that emergency transportation is a stressful event for patients. The question is if simulated emergency transportation might be a useful model to measure the levels of stress-responsive with a high ecological validity. Methods: After approval by the local ethical committee 32 male probationers (age 18–40) were randomized into two groups (‘strain’, ‘control’). The following values were taken: plasma-hormones (epinephrine E, norepinephrine NE, cortisol C) and CVSvalues (BP, MAP, HR). The ‘strain’-group was carried downstairs from a third floor flat and taken into an ambulance for an emergency transport. Blood samples were taken in the flat after informing the probationer (A), at the ground-floor (B) and at the end of a 15 min emergency transportation under defined conditions (C). The CVS-values were recorded continuously . The ‘control’group had to sit on a chair for 5 min and afterwards to lay on a stretcher for 15 min. The blood samples were done at equivalent times. The results were evaluated by a two-factor variance analysis with repetition of the values for the factor measuring time. Results: Our study shows that a simulated emergency transportation induces stress. Differences in stress-responses depending on the period of the simulated emergency transport were found. The increase of E, NE, C and HR during the transport of the probationer down the stairs was significant (P < 0.001); no significant alterations could be shown in the ‘control’ group. The emergency transport in the ambulance appears to be clearly less of a strain to the patient. This was shown by a significant decrease of HR, E and NE levels (P < 0.001) compared to the downstairs part. Conclusion: More attention should be focused on the period of emergency transport from on-scene to the ambulance to influence positively the most stressing event. Further studies concerning sedation before transportation appear to be necessary. P229 Road traffic accident related morbidity and mortality as seen in an emergency department E Pikoulis, F Karlis*, C Theos†, P Koulouvaris, A Geranios*, S Kiose‡, A Tsamatropoulos† and S Mantonakis Second Department of Surgery, *Department of Intensive Care, †First Orthopedic Department, ASCLEPEION Voulas, Vasileos Pavlou 1, 16673,Voula, Athens, Greece. ‡Department of Hygiene and Epidemiology, University of Athens Medical School, Greece Crit Care 1999, 3 (suppl 1):P229 Introduction: Trauma remains the leading cause of death in the first four decades of life. Trauma-related costs is accounted for by accident injuries and the resultant disabilities, lost wages, medical expenses, insurance administration costs and most importantly loss of life become a great national issue in Greece. The purpose of this study is to report in epidemiological manner certain official information regarding prenosocomial events of all traffic accidents in the Southern area of Athens (1 000 000 inhabitants) within a year. The records were a co-operative and cross-matched result from the following services involved : The Department of Surgery and Intensive Care, ‘ASCLEPEION’ Hospital of Voulas, Athens and Department of Hygiene and Epidemiology, Athens University Medical School. Patients and methods: From January 1997 to January 1998, 3211 trauma victims were to 1300 traffic accidents. 2173/3211 (67.7%) were males and 1038/3211 (32.3%) females. The mean age of victims was 39 years (range 14–90 years). In more than 70% of the cases the cause of accident was reported as being ‘human error’ regarding the driver of vehicle. Results: The two most common incidents of the casualties were collision and deviation. 57/3211 (1.8%) victims died either immediately or during transportation to our hospital. From the victims 43 (75.44%) were males and 14 (24.56%) females. The mean age of victims was 54 years (range 12–82 years). The most frequent fatal accident time were the hours between 14:00–24:00 (28 victims = 49.12%). April and July were the most fatal months (8 victims each = 14%).The primary use of Abbreviated Injury Scoring system (A.I.S.) on those who reached the Hospital alive classified 518 cases (16.13%) as having mild injuries and 2693 cases (83.87%) as having medium and/or severe injuries. Morbidity and mortality among the population of Greece were 33238 and 2139 respectively within the above period. Conclusion: Nevertheless newspapers, radio and TV pay more attention to the narcotic and other causes victims than that of the car accidents which is the main reason of deaths among the young. We can conclude that the suitable prehospitalized care of the injured victims and the rapid assessment and resuscitation at the Trauma Centers are the cornerstones of the current treatment and improve the outcome of the injured significantly. P230 Sports activity after severe polytrauma: results of a prospective study RJ Stiletto, P Nowacki* and M Baacke Department of Trauma Surgery/ICU, Philipps-University Marburg, Badinger Str. 35033 Marburg/Lahn, Germany, *Department of Sports Medicine, Justus Liebig University Gießen, Germany Crit Care 1999, 3 (suppl 1):P230 Background: There is only a small body of literature dealing with the problem of sports activity after survived severe polytrauma. Having in mind that most of these patients are in the age group between 18 to 40 years, sports activity after survived polytrauma is a decisive factor of their quality of life. Materials and method: In a prospective trial we evaluated the sports activity and sports performance of a group of 50 polytrauma patients (ISS >15) after a minimum time of 6 months following their discharge from hospital. The characteristics of the group were as follows (mean values): age 28.5 years, follow-up time 18 months, sex: male 40, female 10 patients. The ISS was 50. Cause of injury was in 96% a MVA, in 4% a fall from great height. The APACHE II on the first day was 17. The patients’ time on respirator was 7 days. The stay on ICU was 11, and the stay in hospital 26 days. The sports activity and performance were evaluated according to a standardized score in all patients who practiced sports before the trauma. In addition, a performance test with spiroergometry and serum lactate samples could be performed in seven cases. Results: During the 6 months after discharge from hospital four patients died. The sports status of these patients could not be evaluated. Forty-six patients (92%) were available for further evaluation. The pre- and post-traumatic status of their sports is listed in Table 1. Sports performance and participation levels in differ10 = 21.7% 21 = 45.6% 36 = 78.2% 25 = 54.34% ence activities were evaluated in the 36 patients who practised sport before the trauma. The results are listed in Table 2. Conclusion: According to our results a decrease in activity and performance levels is obvious in the post trauma patient group. More than 70% of the patients practising sports before the trauma had to reduce their activity level. 23.86% had to quit their former activities. However, more than 50% of the patients were able to practice sports after their trauma. 1 = 2.1% Poster abstracts 115 P231 Discomfort, awareness and recall of patients in the intensive care: still a problem? IG Swaiss ICU, King Hussein Medical Centre, PO Box 1115, Amman 11821, Jordan Crit Care 1999, 3 (suppl 1):P231 Introduction: During surgery, anaesthetists take extra care to prevent awareness of any patient who is having any kind of operation done, mainly under general anaesthesia either by using inhalational or intravenous medications, but patients in the ICU, mainly those on ventilatory support, with intubation and sedation, pass through a lot of psychological stress and frustration, which most of the times is not documented in the genera intensive care, and has never been done in our unit. Aim of this study: In this study at our general ICU, we tried to have a proper assessment of this problem in order to avoid it in the future, and to get a proper consensus regarding its existence and solution. Methods: Seventy patients between the ages 20–60 years, were interviewed 1 day after discharge from the ICU, about their memory of events during their stay. Patients with head injury, CNS infection or those who were disoriented at the time of interview were excluded from the study. The remaining 55 patients were oriented to place and time. Intravenous opiates (morphine, pethidine) were used for analgesia as required, while sedation was achieved using midazolam and morphine infusions in appropriate doses as decided by the attending doctors and nurses. Questions asked were generally about patients’ memory of events and about their distressing experiences regarding pain, anxiety, dreams, fear, noises, causes of discomfort and others which will be displayed in the results section. The same questions were repeated 5 days later. Results: The sample of patients were representative of our regular ICU admissions in their age group, APACHE II score and duration of stay. The most distressing and commonest experiences recalled were: anxiety (68%), discomfort from endo-tube (60%), fear (54%), pain (52%), discomfort from N/G tube (48%), difficulty in communicating (33%), dreams and hallucinations (31%), discomfort from physiotherapy (24%), noise (15%), insomnia (13%), thirst (10%), some of these like anxiety, fear, dreams, hallucinations and insomnia had continued since discharge in 6% of patients. None of the studied experiences correlated with age, sex, or with the APACHE II score. On interviewing the patients 5 days later, there were no significant changes in their responses. Conclusion: Our sedation and analgesia in the ICU is not enough to prevent unpleasant experiences, mainly those related to patient awareness. More work is still needed, i.e. using sedation scores to improve our sedation and analgesia in the ICU. P232 Sedation of patients in intensive care units by midazolam (MDZ): clinical and biological evaluation D Chatellier, C Poisson, L Tronchon, D Thévenin, H Robert, P Odou, C Barthélémy and M Luyckx Réanimation Médicale Polyvalente Centre Hospitalier du Docteur Schaffner 99, route de la Bassée 62307 Lens, France Crit Care 1999, 3 (suppl 1):P232 Aim: To assess if the clinical scoring of sedation (Ramsay scale), the administered dose of MDZ, the serum levels of MDZ from the beginning to the end of sedation are related to clinical parameters (body area), biological data (creatinine clearance, liver enzymes, protidemia), and pharmacokinetic parameters (elimination half-life T1/2). Patients and methods: The study was conducted with 31 patients (70 ± 10 year-old ; IGS II = 41 ± 14). The objective was to reach a score of sedation of 2 up to 4. Sedation of patients was initiated with an intravenous bolus of MDZ (B = 0.1 mg/kg) and maintained with MDZ at the rate (H1 = 0.08 mg/kg/h). If needed, the dose of MDZ was gradually increased: H = 1/2B + 1,5H ; H = 1/2B + 2H1 2 1 3 (if H3 was insufficient, sufentanil was added (0.17 mg/kg/h and 0.34 mg/kg/h)). Waking up of patients was monitored by the beginning of respiratory weaning. Liver enzymes, protidemia and creatinine clearance are evaluated every day and 24 h after the end of sedation.The serum levels of MDZ and its metabolites were measured by HPLC and RRA every 8 h during the first day; then every 24 h, before and after each change of posology and finally every 4 h after the end of sedation for 24 h. The correlations between the different parameters monitored were evaluated by a Pearson’s test. Results: No correlation between time to awakening (22 ± 21h) and duration of sedation (96 ± 57 h) or clinical parameters or biological data was observed. In a similar way, score of sedation, posology and serum levels of MDZ were not correlated. The pharmacokinetic parameters of MDZ were : T1/2 = 11.77 ± 4.8 h, clearance = 8.6 ± 4 l/h, Vd = 149 ± 98 l, concentration at steady state = 1008.7 ± 395 ng/ml. The unique parameter modulating the time to awakening was T1/2 of benzodiazepinique total activity (T1/2 = 12 ± 4.96 h) with 7 patients. T1/2 benzodiazepinique total activity (h) P233 Cardiovascular effects of dexmedotomidine for ITU sedation: UK results of a multi-centre study (St George’s, University College, St Thomas’s and Bristol Royal Infirmary Hospitals) CJ Bradshaw, RM Venn, R Spencer, D Brealey, E Caudwell, M Singer, D Treacher, SM Willatts and RM Grounds St George’s Hospital, Blackshaw Road, London, SW17 0QT, UK Crit Care 1999, 3 (suppl 1):P233 Introduction: A multi-centre study examining the safety and efficacy of the novel sedative agent dexmedetomidine, a highly selective alpha-2 agonist, possessing analgesic and sympatholytic properties. Methods: One-hundred and nineteen post-operative patients who required sedation and ventilation for at least 6 h on the ITU were enrolled. Ninety-eight completed the randomised, placebocontrolled, double-blind study (81 cardiac and 17 general surgical) in four centres in the UK, but all patient data was used in the safety analysis. Within 1 h of return from theatre, the study drug was started with a loading dose of 1 mg/kg for 10 min, followed by a maintenance infusion of 0.2–0.7 mg/kg/h to maintain a Ramsay sedation score of ³3 and was continued for 6 h after extubation (maximum duration 24 h). Rescue sedation and analgesia was provided with midazolam and morphine respectively. Heart rate, systolic, diastolic pressures and central venous pressures were recorded at 10 min intervals for the first 30 min and then hourly. Results: Patient demographics were comparable as were Ramsay sedation scores between the two groups. The average dexmedetomidine infusion rate was 0.35 mg/kg/h whilst intubated and 0.15 mg/kg/h after extubation (range 0–0.7 mg/kg/h). Data was collated for the initial 6 h of the infusion and for the period pre- and post-extubation ± 4 h, hence, allowing for the variation in the duration of intubation in the data analysis. Once adequately sedated the patients receiving dexmedetomidine achieved greater cardiovascular stability as compared to the placebo group, with a significantly lower and less variable heart rate (P = 0.0001), this was clearly demonstrated in the period around extubation when mean heart rate in the dexmedetomidine group was 75 (SEM ± 2.0), versus 92 (± 2.9) in the placebo group. Diastolic blood pressure showed a similar trend with a reduction of 5 mmHg in the dexmedetomidine group, but no sustained significant differences in systolic arterial pressure or central venous pressures. Of the 66 patients who received dexmedetomidine, 16 had transient episodes of hypotension (MAP <60 or >30% reduction from pre-infusion BP) and/or bradycardia (HR <50), mainly during the loading dose, of which three patients required temporary interruption of the infusion and three others required termination of the infusion. Summary: Dexmedetomidine may improve cardiovascular stability. P234 Ovarian hyperstimulation syndrome (OHSS) at a maternity hospital V Lappas, P Myrianthefs, C Ladakis, S Pactitis, A Carousou, J Stamatiou and G Baltopoulos Athens University School of Nursing Intensive Care Unit at ‘Agioi Anargyroi’ Cancer Hospital of Kifissia, Nea Kifissia 14564, Greece, Department of Intensive Care Unit of ‘IASO’ Maternity Hospital at Athens, Marousi 15123, Greece Crit Care 1999, 3 (suppl 1):P234 Background: Ovarian hyperstimulation syndrome (OHSS) is a clinically important entity due to assisted conception which occurs in about 1–10% of in vitro fertilization (IVF) cycles with serious complications such as deep vein thrombosis, hypovolaemia, haemorrhage, respiratory distress and hepato-renal failure. Objective: The aim of this study was to describe our experience with OHSS at ‘IASO’ Maternity Hospital. Materials and methods: The last year seven patients with age 30 ± 2.4 (X ± SEM) were admitted in our ICU due to severe ovarian hyperstimulation syndrome complications. Results: Signs and symptoms (Table 1) and labs (Table 2) were due to third space fluid shift (increased capillary permeability) with evidence of hypovolaemia, haemoconcentration and dehydration. Ultrasound examination of the abdomen showed ascites, pelvic fluid and enlarged ovaries (in our patients >11 cm in diameter) in all patients and chest X-ray revealed hydrothorax in five patients (71%). Ovarian hyperstimulation syndrome clinical feature is due to exaggerated ovarian response characterized by marked elevation of serum oestradiol levels and the presence of a large number of follicles (>20). Management and outcome: All patients had bed rest, fluid input–output control, adequate fluid intake, high protein oral intake, human albumin solutions iv and LMWH sc (nadroparin Abdominal distension or pain WBC × 103/ml Poster abstracts 117 calcium 3000 iu). Two patients had paracentesis of hydrothorax because of dyspnea or discomfort. Hospital and ICU stay was 8 ± 3.3 and 5 ± 1.9 days, respectively. All patients recovered without developing any life threatening complications and were discharged in good condition. Conclusions and discussion: Ovarian hyperstimulation syndrome is a serious clinical condition [1] which may be complicated by life threatening events in up to 0.5–2% [1,2]. Early recognition and management until normalization of oestradiol serum levels provide good outcome with mortality rate 0.0025% [1]. P235 Anticoagulation: hitting the target after cardiac surgery CD Booth and CL Nelson Pharmacy Department, Leeds General Infirmary, Leeds, UK. E-mail: Crit Care 1999, 3 (suppl 1):P235 Introduction: A pharmacy led anticoagulant service has recently been introduced to dose and monitor warfarin in all cardiothoracic inpatients at the Leeds General Infirmary. This abstract presents an audit of locally produced guidelines for the induction of warfarin in cardiothoracic patients. Aim: To improve the anticoagulant process for cardiothoracic patients by using the experience of clinical pharmacists to produce guidelines for induction of warfarin. Results: An audit was undertaken and data was collected on 89 patients. Sixty patients (67%) received a warfarin loading dose according to the local guidelines. Fifteen (71%) of the 21 patients with mechanical valves had an acceptable INR on day four. Only one patient (5%) had a high INR, and 5 (24%) had a low INR. Of the 39 ‘low risk’ patients (tissue valves, coronary endarterectomies and A.F), 21 (54%) were within the acceptable range on day 4 whilst four (10%) were high and 14 (36%) were low. In a group of 29 patients where guidelines were not followed (dosing decisions were made by junior surgeons), only 8 patients (28%) had an acceptable INR on day four, 16 (55%) had a low INR and 5 (17%) had a high INR. Discussion: This study has shown that the locally developed guidelines can be used to safely initiate warfarin in cardiothoracic patients immediately following cardiac surgery. In the future we intend to undertake an analysis to produce maintenance dose guidelines which are specific to cardiothoracic patients. A combination of these two guidelines should optimise the dosing of warfarin in cardiothoracic patients and contribute to an overall improvement in their care. P236 A prospective study of thrombocytopenia and prognosis in intensive care A De Weerdt, S Vanderschueren, M Malbrain*, D Vankersschaever, E Frans, A Wilmer and H Bobbaers Department of General Internal Medicine, Medical Intensive Care Unit, University hospitals, Herestraat 49 3000 Leuven, Belgium and *Department of Intensive Care, Ste-Anne St-Remi Hospital, Boulevard Jules Graindor 66, 1070 Brussels, Belgium Crit Care 1999, 3 (suppl 1):P236 Introduction: To study the incidence and prognosis of thrombocytopenia in an adult critically ill population, 329 patients consecutively admitted during a 5-month period to the medical intensive care unit (ICU) of a university hospital (212 patients) and a medical-surgical ICU of a regional hospital (117 patients), were prospectively surveyed. The primary outcome measure was ICU mortality. Results: One hundred and thirty-six patients (41.3%) had at least one platelet count < 150×109/l. These patients displayed a higher APACHE (Acute Physiology and Chronic Health Evaluation) II, SAPS II (new Simplified Acute Physiology Score) and MODS (Multiple Organ Dysfunction Score) at admission, longer ICU stay (8 versus 5 days median (interquartile range)) and a higher mortality rate (crude odds ratio, OR = 5.0, 95% confidence interval, CI 2.7–9.1) than those who never developed thrombocytopenia (P < 0.0005 for all comparisons). Bleeding incidence rose from 4.1% in non-thrombocytopenic patients to 21.4% in patients with minimal platelet counts between 101 and 149×109/l (P = 0.0002), and to 51.9% in patients with minimal platelet counts <100×109/l (P < 0.0001). 19.5% of the study population died in the ICU following the index admission. Eighteen of 193 patients (9.3%) who never became thrombocytopenic died, versus 31 of 89 patients who were thrombocytopenic at admission (OR = 5.2, 95% CI 2.7–9.8, P < 0.0001) and versus 15 of 47 patients (31.9%) who developed thrombocytopenia later on during ICU stay (OR = 4.6, 95% CI 2.1–10.0, P = 0.0002). In addition we found that a drop in platelet count to £50% of admission was associated with higher death rates (OR = 6.0, 95% CI 3.0–12.0, P < 0.0001). In a linear regression analysis, adjusting for admission APACHE II, SAPS II and MODS, admission thrombocytosis and the occurrence of bleeding, nadir thrombocytosis remained significantly related to ICU mortality. Conclusion: Thrombocytopenia is a simple and readily available risk marker for ICU mortality, independent of and complementary to established severity of disease indices. Both a low nadir thrombocytosis and a significant fall of platelet count predict a poor vital outcome in adult ICU patients. P237 Platelet function and inflammatory markers in septic patients U Leonhardt, F Zeiger, M Koksch and L Engelmann University Leipzig, Department of Internal Medicine I, Philipp-Rosenthall-Str. 27, 04103 Leipzig, Germany Crit Care 1999, 3 (suppl 1):P237 Background: In septic patients disseminated intravascular coagulation is a severe complication whereby an altered platelet function appears contributory. Clinical outcome depends on an early diagnosis and sufficient therapy. In the present study the association of platelet function to inflammatory markers indicating disease severity was investigated. Methods: Inflammatory markers C-reactive protein, procalcitonin, interleukin-6 and interleukin-10 were measured using standard methods in 18 patients fulfilling clinical, inflammatory and hemodynamic criteria of sepsis. Platelet activation marker P-selectin was flow cytometrically analysed ex vivo and after stimulation using 5 mmol/l ADP and 10 mmol/l TRAP-6. Results: Flow cytometrically measured platelet function was tightly associated with inflammatory markers. Pre-activation of platelets in the circulation was significantly correlated to plasma levels of procalcitonin (P < 0.023), whereas in vitro induced reagibility after ADP- and TRAP-6 stimulation correlated well with the plasma concentration of the C-reactive protein (P < 0.001; P < 0.012). Furthermore, a close relation of IL-6, but not of IL-10, plasma levels to TRAP-6 stimulated P-selectin expression was observed (P < 0.033). Conclusion: Platelet function was demonstrated to be tightly associated with the inflammation process in septic patients. Whether this finding may be a useful marker for disease severity and the development of a disseminated intravascular coagulation should be clarified in prospective studies. P238 Retrospective study of patients with haematological malignancies admitted in an intensive care unit F Faria, P Alves, E Gonçalves*, A Martins, L Viterbo*, F Viseu* and A Aguiar Intensive Care Unit and *Onco-haematology Unit, Instituto Português de Oncologia, Porto, Portugal Crit Care 1999, 3 (suppl 1):P238 Introduction: The development of aggressive schemes of chemotherapy predisposes haematological patients to various lifethreatening complications. The admission of neutropenic patients into an intensive care unit (ICU) is still controversial mainly if they have multiple organ dysfunction (MOD) and /or if mechanical ventilation is required. Objective: Analyses from patients with haematological malignancies admitted in a medico-surgery ICU of an oncology hospital. Patients and methods: Retrospective observational study on patients with haematological malignancies admitted in ICU from October/96 to October/98, coming from Paediatric Department (PD), Onco-Haematological Unit (OHU) and Bone Marrow Transplantation Unit (BMTU). We analysed the patient data, namely the underlying malignancy, the reason for admission, the type and number of organ dysfunction (including neutropenia and requirement of mechanical ventilation), the time in ICU, acute physiology, age, chronic health evaluation (APACHE II) and sepsis-related organ failure assessment (SOFA). Results: Between October/96 and October/98, 46 onco-haematological patients were admitted in the UCI (56 inpatients) with ages from 9 months to 70 years old, 23 female/23 male: 6 came from PD (13%), 29 from OHU (63%) and 11 from BMTU (24%). Underlying haematological malignancy: Non Hodgkin Lymphoma (34%), Acute Myeloid Leukaemia (21%), Chronic Myeloid Leukaemia (15%), Hodgkin Disease (15%), Acute Lymphoid leukaemia (11%), Multiple myeloma (4%). Six of the 46 patients were excluded because of the short time in ICU (£12 h). Six patients were readmitted. The mean time of stay was 8.2 days. The reasons for ICU admission were: acute respiratory failure (54%), multi-organ dysfunction (MOD; 14%), post-surgery (14%), septic shock (8%), tumour lysis syndrome (6%), hypovolemic shock (2%) and neurological dysfunction (2%). The ICU mortality was 52.5%, being 76% of them neutropenic patients with MOD and requiring invasive ventilation. 89% of the patients coming from BMTU died. Conclusion: The main risk factors to dead in an ICU are the number of organ dysfunction at admission, the requirement of invasive ventilation, BMT, APACHE II ³20 and SOFA ³15. P239 Prognostic value of the bone marrow in severe sepsis/septic shock R Milheiro, E Lafuente, A Bártolo, A Sousa, C Gonçalves, J Fernandes, M Martins, J Leão, F Santos and P Carvalho Intensive Care Unit, Hospital de Senhora de Oliveira, 4810 Guimarães, Portugal Crit Care 1999, 3 (suppl 1):P239 Introduction: Peripheral haematological changes are one of the sepsis diagnosis criteria. However, there are only a few studies concerning the effects of severe sepsis/septic shock in bone marrow of the adult patient. Objectives: Characterise the bone marrow haematological changes in severe sepsis/septic shock patients and to evaluate the prognostic value of the marrow cell differential count (myeloid, lymphoreticular, erythroid series). Materials and methods: Prospective study of 29 patients with the diagnosis of severe sepsis/septic shock of different etiologies. Age, SAPS II in the first 24 h, organ dysfunctions according to SOFA, organ failure according to Knaus and the final outcome were considered in the present study. Poster abstracts 119 The bone marrow of each patient was studied and a differential count considering the myeloid, lymphoreticular and erythroid series was made. The patients were separated according to final outcome (dead and alive) and the bone marrow differential counts were compared between the two groups applying t Student test. Results: See Table. Conclusion: In the present study significant statistical correlation was found between lymphoreticular count and mortality. We can conclude that bone marrow evaluation has had a prognostic value in this patient group. Dead (n = 17) Alive (n = 12) Myeloid series (%) Lymphoreticular series (%) 10.6 ± 4.5 Erythroid series (%) Mortality rate 58.86% P240 Monitoring of plasma lipid peroxide level after abdominal aortic reconstruction in humans MS Ryszka, P Guzik*, T Zujewski*, K Rzetecka*, M Kempa*, A Wykrêtowicz*, B Sawarzyñska-Ryszka, R Szulc and H Wysocki* Institute of Anaesthesiology and Intensive Therapy, University School of Medical Sciences, Poznañ, Poland; *Division of Cardiology, Intensive Therapy, University School of Medical Sciences, Poznañ, Poland Crit Care 1999, 3 (suppl 1):P240 Aortic reconstructive surgery is associated with post-ischemic reperfusion and oxidative stress. It is expected that oxidative stress should be self-limiting during healing process in the postoperative period. Lipid hydroperoxides (LHP) are one of oxidative stress markers therefore we evaluated changes in LHP level in the course of uncomplicated healing in patients who underwent abdominal aortic reconstruction. Ten male patients, aged 56–74 years (mean 65.5 ± 6.01) with abdominal aortic aneurysm or aortoiliac occlusive disease were submitted to aortic grafting operation. LHP concentration was measured in blood samples collected via central line prior to (P), at the end of (E) and 1 h, 24 h, 48 h and 72 h after surgery. The results are presented as mean ± SEM. *Nonparametric one-way ANOVA–Kruskal–Wallis test LHP concentration was significantly increased at the end of surgery and started to decrease just after 1 h later reaching the initial level within 48 h. The obtained results indicate limitation of the oxidative stress in the course of uncomplicated healing. The results also suggest that LHP level can be used for monitoring of oxidative stress activity in humans. P241 Deep leg veign thrombosis in multiply injured patients: an underestimated problem? Results of a prospective clinical study with 50 patients RJ Stiletto, K Giannadakis and R Leppek* Department of Trauma Surgery/ICU and *Department of Radiology Philipps-University Marburg, Baldinger Str. 35033 Marburg/Lahn, Germany Crit Care 1999, 3 (suppl 1):P241 Introduction: Too little is still known about the incidence rate of thromboembolic complications in polytrauma patients after ICU treatment, as only a small amount of data is available on this topic. The majority of the studies published to date that have been performed to assess the incidence rate of thrombosis in multiply injured patients only refer to the clinical symptoms of a venous thrombosis. A systematic screening-examination for the assessment of the incidence rate of thromboembolic complications in the above-mentioned patient collective has not yet gained acceptance as a routine method in clinical practice. Material and method: Between January 1996 and December 1997, 50 polytrauma patients were included in a prospective clinical study. Including criteria were: an initial ISS-score >16, a stay on the ICU of at least 72 h and a time on the respirator of at least 72 h. All patients were examined for a deep veign thrombosis by using a standardized protocol and by means of a colour-coded duplex (ccd) sonography. In cases in which the clinical or/and sonographic examination yielded results of a suspected veign thrombosis, a phlebography was performed. In cases of a suspected pulmonary embolism a pulmonary angiography was performed. The colourcoded duplex sonography was used before the patients were mobilized or transfered to an other ward (generally after 15 days). Results: If not indicated otherwise numbers are given as median. The age of the 38 male and 12 female patients was 38.6 years. The severity of trauma was characterized by an ISS-score of 39.5 points. Eight patients died of a multiorgan-failure during their stay on the ICU. The autopsy findings reveal that no patient died of the of a veign thrombosis or a pulmonary embolism. Of the remaining 42 patients, 8 patients (19%) showed deep leg veign thrombosis in the ccd. In three of these patients (7%) also a pulmonary embolism occurred. Conclusion: Having in mind the results of our study the incidence rate of thromboembolic complications in polytrauma patients seems to be much higher as expected in comparison to the published results of other authors. P242 Obstructive shock in pulmonary embolism: thrombolytic therapy and survival S Pivetti, E Aluffi, L Bonino, S Valpreda, R Urbino, B Tartaglino, F Navone, C Antro and V Gai Medicina d’Urgenza e P.S. Medicina, E.D., Az. Osp. ‘ S. Giovanni Battista’ diTorino, Torino, Italy Crit Care 1999, 3 (suppl 1):P242 Study objectives: Shock due to massive pulmonary embolism (PE) shows a variable prevalence in literature, without general agreement about thrombolytic therapy effectiveness. Objective of the study was to appreciate prevalence and main clinical features of obstructive shock (OS) in patients with PE admitted to our departement, and to evaluate thrombolytic therapy effectiveness (BAPE regimen). Methods and results: 236 PE cases were treated from March 95 until June 98 ; 24/236 suffered OS (10.2%, 14 F, 10 M, mean age 69 years). In 91.6% of OS we found one risk factor, at least, and in 62% two or more risk factors. 3/24 patients presented with cardiac arrest, 7/24 showed RBBB and 5/24 S1Q3T3 pattern on EKG, 9/24 showed a normal EKG. Echocardiography, performed in 66% of patients, detected in all cases an enlarged and hypokinetic right ventricle; venous duplex ultrasound, performed in 70% of cases, detected DVT in 70.5%; perfusion radionuclide lung scan, performed in 70.5% of cases, showed a high probability pattern in 94%. D-dimer was altered in all cases; ABG analysis showed hypoxemia in all cases. 13/24 patients with OS were given thrombolysis according to BAPE regimen (rTPA 0.6 mg/kg over 15 min); 11/24 patients with OS were not given thombolysis because of absolute contraindications. Thrombolytic therapy decision-making rested on clinical data, on echocardiography in 38% of case and on echocardiography and lung scan in 61% of cases. Intra-hospital overall death-rate was 37.5% (9/24 patients); all 13 patients given thrombolysis were alive at discharge, whereas, 9/11 (81.8%) patients not given thrombolysis died in the hospital. Conclusion: We found OS in 10.2 % of PE cases; 13 patients given thrombolysis all were alive and showed stable hemodynamic parameters at discharge, whereas 9/11 patients not thrombolysis given died during hospital stay. This outlines the need of an expeditious clinical and instrumental diagnosis as a tool of decisionmaking, especially about thrombolytic therapy. Moreover, we found a 100% sensibility of D-dimer, hypoxemia as detected by ABG analysis, echocardiography and perfusion radionuclide lung scan. F Guarracino, D De Cosmo, D Penzo, M Tedesco, A Bossi and R De Stefani Department of Cardiothoracic Anaesthesia and ICU, Umberto I Hospital, Via Circonvallazione 50, 30171 Mestre (VE), Italy Crit Care 1999, 3 (suppl 1):P243 Introduction: Aortic valve prosthesis determine a transvalvular gradient (Dp) with changes in aortic flow that can affect left ventricular geometry and function, implanted prosthesis and aortic route. In order to improve prognosis a new prosthesis has been proposed , the so called ‘stentless valve’ (SV), whose main characteristic is the absence of the supporting ring. Aim of our study was to evaluate if such valve could influence early postoperative course in ICU. Methods: Forty patients, age 67 ± 11 and EF 56 ± 14, undergoing aortic valve replacement were enrolled. Nineteen patients, 12 with aortic stenosis (AoS) and seven with insufficiency (AoI) underwent SV implantation (group S); 21 patients, 13 with AoS and eight with AoI, received mechanical valve (group M). Anaesthesia with remifentanil and propofol, moderate hypothermia (30°C) and anterograde blood cardioplegia were used. In all cases mechanical ventilation (MV) and intubation time, need for inotropic support and blood loss were registered during ICU stay. Results: No differences were found in duration of MV (125 ± 30 min in group S versus 136 ± 12 min in group M, P > 0.05) and intubation (3 h in group S versus 3.4 h in group M, P > 0.05) in patients with aortic stenosis. In patients with AoI MV and intubation time was shorter in group S (respectively 140 ± 25 min versus 155 ± 18 min in group M, P < 0.05; 3.9 h versus 4.5 h in group M, P < 0.05). No differences were observed in blood loss between two groups, nor in dopamine dosage (5.4 mg/kg/min versus 6.6 mg/kg/min, P < 0.05). Discussion: Our results show no differences in early postoperative outcome in patients with AoS when treated with mechanical or SV. Vice versa SV seems to improve ICU course of patients with AoI, with regard to duration of MV and intubation. Other studies with echocardiography are necessary to clear if these differences can be due to a lower aortic transvalvular gradient of SV. P244 High risk patients in major thoracic surgery G Della Rocca, F Ruberto, F Pugliese, L Pompei, C Coccia, MG Costa and P Di Marco Istituto di Anestesiologia e Rianimazione, Dir Prof A. Gasparetto, University of Rome ‘La Sapienza’ Via del Policlinico n°155-00161 Rome, Italy Crit Care 1999, 3 (suppl 1):P244 Lung resections are correlated to high mortality (4–6%) and morbidity (20–40%) that can increase in high risk patients. Objectives of this study is to analyze preoperative risk factors, in a group of high risk patients undergoing thoracotomy for lung cancer and to assess the relationship with postoperative complications. P245 Outcome of systemic rheumatic disease patients admitted in intensive care unit B Bouffandeau, B de Cagny, V Jounieau, F Tinturier, Y Domart, PY Lallement, H Gayet and A Fournier Unité de Réanimation Néphrologie, hôpital sud - 80054 Amiens, France Poster abstracts 121 3 arrhythmia, 1 PE, 1 resp 1 MI (died), 1 resp Table. Preoperative risk factors and perioperative complications Age + cardiovascular Age + respiratory Age + cardiovascular + other Age + respiratory + other Age + cardiovascular + respiratory Cardiovascular + other Respiratory + cardiovascular Methods: From January 1996 to December 1997 43 patients, undergone pulmonary resection for lung cancer, were considered at high risk and enrolled in this study according to one or more of the following including criteria: age older than 70 years; previous cardiovascular disease; poor pulmonary function (FEV1 <65% predicted values, PaO2 <65 mmHg or PaCO2 >42 mmHg); chronic systemic disease. Patients clinical data are reported in the Table. Anesthetic technique was the same for all patients. All the patients were monitored with EKG, pulse oxymetry (Nellcor N200), invasive arterial pressure, pulmonary artery catheter when necessary and in-end expiratory gas analysis. Preoperatively an epidural catheter was inserted in T6-T11 space. Anesthesia was maintained with isoflurane 0.5% vecuronium and fentanyl combined with epidural analgesia (bupivacaine 0.5% and fentanyl). A continuous infusion through the epidural catheter of morphine 20 mg in 250 ml normal saline 0.9% at 5 ml/h was used for postoperative pain relief. Surgical procedures included: 33 lobectomy, 4 bilobectomy, 3 sleeve resections, 2 pneumonectomy. Relationship among different preoperative risk factors and postoperative complications were performed with c2 test and corrected with Fisher’s exact test. Results: Mean age was 69 yrs (range 50–83 years). All patients were extubated in the operative room at the end of surgical procedures. Complications occurred in 25.5% of patients (11/43): 3 arrhythmias, 2 myocardial infarctions, 2 pulmonary edema, 2 acute renal failures, 2 pulmonary complications (prolonged air leakage) (Table). The perioperative mortality rate was 4.6% (2/43). The mean length of staying in hospital was 11 days for all patients, 12.5 for respiratory group, 9.6 for cardiac group, 10.9 for age group. Conclusion: In our experience lung resections in high risk patients have low mortality and morbidity. Therefore, age over 70 years Crit Care 1999, 3 (suppl 1):P245 Objective: The aim of this study was the determination of short and longterm outcomes and prognostic factors for patients with systemic rheumatic diseases (SRD) admitted to intensive care units (ICU) in a retrospective case series study of SRD patients admitted in six French ICU in community and teaching hospital between January 1992 and July 1996. Main results: A total of 60 SRD patients were included with diagnostic of infection (40%), acute exacerbation of SRD (16.7%), iatrogenic complication (16.7%), cardiovascular complication (15%), and miscellaneous (11.7%). The death rate in intensive care units was 26.7% (16/60). Multivariate analysis (Cox model) identified two factor predicting poor MICU outcome: age above 65 years (relative risk [RR], 3.3; 95% confidence interval [CI], 1.9–5.8) and Tran organ failure indices (RR, 2.2; 95% CI, 1.7–2.8). The mean overall survival time after admission to ICU was 18.8 months. The 1-year survival rate was 61.1%, and the 2-years 58.8%. Multivariate analysis (Cox model) identified two factors predicting poor long term outcome: age above 65 years (RR 4.0; 95% CI 2.7–6.0), and need of mechanical ventilation (RR, 6.5; 95% CI, 4.2–10.1) (Fig). MI, myocardial infarction; PE, pulmonary edema; RF, renal failure alone has no longer to be considered a limiting factor in patients undergoing surgery for lung cancer. High risk patients need a very careful preoperative evaluation of cardiovascular and pulmonary function in order to avoid perioperative complications and to reduce the morbidity. An appropiate surgical and anesthetic technique, and postoperative pain relief improves outcome in high risk patients. Figure. Survival of patients with SRD in intensive care unit, influence of mechanical ventilation. Conclusion: We conclude that this SRD patients should be admitted to the ICU on the same basis as other patients. In this population neither the diagnostic of the underlying disease, nor the use of immunosuppresive therapy did influence the short and long outcome. Long-term survival depended only on the age and the need of mechanical ventilation. Critical Care 1999, Vol 3 suppl 1 P247 Time and type of admission to a surgical intensive care unit P Haraldsen and R Andersson Department of Surgery, Lund University Hospital, S-221 85 Lund, Sweden Crit Care 1999, 3 (suppl 1):P246 Surgical intensive care consumes considerable facilities and the associated costs are high. The present study aimed at evaluating longterm outcome of patients treated due to abdominal sepsis in the surgical intensive care unit from January 1983 to December 1995 by a follow-up from June to August 1997 of patients surviving the hospital stay. The patients were interviewed by telephone and also completed a ‘quality-of-life’ form. Out of 210 patients (mean age 65 years) 151 survived the hospital stay. At follow-up, another 45 patients were deceased, 41 patients were not reached MW Sebastian, WJ Fulkerson and NW Knudsen Duke University Medical Center, Durham, NC, USA Crit Care 1999, 3 (suppl 1):P247 Introduction: Duke University Medical Center (DUMC) is a tertiary care hospital with a Level 1 (USA) Trauma Center Designation. Increasing level of patient acuteness, high census levels, decreasing resident staffing and financial concerns have led to intensive care unit (ICU) organization and staffing changes. ICU care is being redefined at DUMC via pursuit of a multidisciplinary approach to the treatment of critically ill patients. As part of this initiative, analysis of Surgical Intensive Care Unit (SICU) admissions was performed for January through March 1998. This analysis showed that 45% of admissions occurred when there was no attending in house. To fulfill the missions of patient care, education, research, cost-containment, optimal bed utilization and appropriate reimbursement for services, we instituted around-theclock board-certified intensivist coverage in the SICU. Continuing analysis of admission distribution confirms that half of admissions occur at night and breakdown of type of admission indicates that these admissions are the patients most requiring active resuscitation and supervision of resident management. and another 17 patients declined to participate. Thus, the followup included 48 patients. At discharge from hospital, 54% of the patients returned directly home and 67% returned to their regular work after a median sick-leave of 10 weeks. When comparing a quality-of-life score, an impairment of median scores (P < 0.01) was found, although the patients subjectively appreciated quality of life not to have changed significantly. 49% claimed full recovery. Hospital mortality was 28% attributable to multiple organ dysfunction and total mortality over the time period was 50% and rarely associated with abdominal sepsis. Thus, recovery following abdominal sepsis treated in the surgical intensive care unit is good and motivates efforts performed during the acute phase. Results: There are approximately 115 admissions per month to this 16 bed ICU for a total of 575 admissions for the study period. From 6 PM to 6 AM, 276 (48%) admissions occurred encompassing 88% of trauma patients and 79% of floor transfers. The time distribution was constant for each month and the incidence of postoperative, direct admission, and floor transfer was also constant from month to month, while the incidence of trauma admissions was higher in July and August. Methods: To determine time and type of SICU admissions we retrospectively reviewed the SICU database from July through November 1998. Time of arrival was divided into 12-h blocks beginning at 6 AM and 6 PM. Patients were divided into four categories: postoperative, direct admission, trauma and floor transfer. Conclusion: Fifty percent of admissions to the DUMC SICU occur during off-hours when traditionally there has been no attending level in-house supervision. The high percentage of trauma and floor transfers during off-hours validates this reorganization of ICU staffing and around-the-clock supervision. P248 Preliminary data: PIM and Prism in infants and children post cardiac surgery in a UK PICU GD Jones, M Hatherill and IA Murdoch Paediatric ICU, Guys Hospital, London SE1 9RT, UK. Tel: 0171 955 2564; Fax 0171 955 2563 Crit Care 1999, 3 (suppl 1):P248 Objective: To describe the predictive and calibration capabilities of PIM and PRISM in infants and children following cardiac surgery. Design: Between December 1997 and November 1998, 250 consecutive infants and children were studied. No child died in theatre. There were; 53 patients <1 month, 75 from 1 month–1 year and 122 >1 year. Median age 11.43 months (range 0.02–229). Survivors were defined by ICU discharge. Results: Crude mortality was 6% (15/250) all deaths occurred in children <1 year old. Median age of death (range) was 0.33 months (0.02–11.83). Median time (range) to death was 53 h (2–264). Table. Observed vs (predicted) deaths and area under the ROC curve for PRISM and PIM Poster abstracts 123 Calibration using the Hosmer-Lemeshow goodness of fit test, showed a c2 16.15, df 8, significance 0.04 for PRISM and c2 17.05, df 8, significance 0.03 for PIM. Using a cut off at P = 0.5, sensitivity and specificity for PRISM was 98.3% and 33.3%, and 99.2% and 26.7% for PIM. compares favourably with the original work by Shann et al. [1] (0.87 vs 0.83). Therefore we would concur with their conclusion that PIM is accurate enough to describe the risk of mortality in groups of children, and has the added advantage of needing less data collection than PRISM. Conclusion: Neither PRISM, nor the new scoring system PIM are well calibrated for predicting individual mortality. However, despite the small numbers, the area under the ROC plot for PIM P249 Does intensive care improve outcome? CD Gomersall, PY Tan, GM Joynt, TA Buckley and E Wong Department of Anaesthesia & Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. Tel. 44 171 886 1248; Fax. 44 171 886 6360; E-mail. Crit Care 1999, 3 (suppl 1):P249 Introduction: ‘Does intensive care improve outcome?’ is a question of fundamental importance. It is unlikely to ever be answered conclusively, because of ethical constraints on performing a controlled study of two groups randomised to ICU admission or no ICU admission. It is possible however, to assess ICU admission as an independent predictor of survival when considered alongside other possible predictors. Method: Prospective cohort study of all adult patients referred for emergency admission to the only adult ICU of a university hospital during a 3-month period. Because of the limited number of alternative ICU beds patients refused admission are not transferred to an ICU in another hospital. Exclusion criteria were: direct ICU transfers from other hospitals, patients referred when the ICU was full, patients with acute burn injury and cardiac surgery patients. (The latter two groups were excluded from the original MPM II derivation and validation sets). MPM II0 score was calculated for each patient and the following data were collected: sex, referring specialty, APACHE II diagnostic weighting, admission or refusal of admission to ICU and hospital survival. MPM II0 consists of 14 physiological and diagnostic variables and is the only severity scoring system available at ICU admission. Logistic regression analysis using a forward stepwise conditional method was performed using SPSS for Windows. Variables included as possible predictors of survival were sex, MPM II0, APACHE II diagnostic weighting, ICU admission, and interactions between admission and MPM II0, and admission and APACHE II weighting. Results: Three hundred and eighty-three patients were studied of whom 229 were admitted. Low MPM II0, low APACHE II diagnostic weighting and admission to ICU were found to be independent predictors of hospital survival with a hospital survival odds ratio for ICU admission/ refusal of 2.41 (95% CI: 1.48–3.93). Discussion: This result demonstrates that admission to ICU is an independent predictor of survival when compared with available likely predictors. It is unlikely that the association between admission and survival is due to selective admission of those patients more likely to survive as the association was independent of severity of illness, type of illness and sex. Our results therefore strongly support a positive answer to the question ‘Does admission to ICU improve outcome?’. S Grmec, S Piberl and V Gasparovic* EMS, PHU Maribor, Ul. Talcev 9, Maribor 2000 Slovenia, *Division of Intensive Care Medicine, University Hospital Centre Zagreb, Kispaticeva 12, 1000 Zagreb, Croatia Introduction: Due to the numerous prehospital descriptive scoring system it is uncertain whether they are efficient in the description of how serious illness are and furthermore whether they can have prognostic role in the estimation of the illness outcome (what is their validity in connection with the prognostic scoring system APACHE II). Methods: In prehospital setting were collected from each patient postintervention values of the MEES and GCS. The APACHE II score were recorded on the day of admission to hospital. This study was undertaken over a 2 year period (January 1996 to October 1998) and included 286 consecutive patients hospitalized for nontraumatic coma. Patients less than 16 years old were not included. There were 168 men and 118 women. Their age varied from 16 to 87 years with a mean 51.8 ± 16.9. Sensitivity, specificity and correct prediction outcome measured by the c2method in four severity scores. The Youden Index was also obtained. The best cutoff point in each scoring system was determined by the Youden index. The difference in Youden index was calculated by Z score. A P value <0.05 was chosen to reject the null hypothesis. For each score receiver operating characteristically curve (ROC) were obtained. The difference in ROC was calculated by Z score. Results: For prediction of mortality, the best cutoff points are 19 for APACHE II; 18 for MEES and 5 for GCS. The Youden index has best cutoff point at 0.63 for APACHE II, 0.61 for MEES and 0.65 for GCS. Correct predictions outcome (%) was for APACHE II 79.9 ± 1.6; for MEES 78.3 ± 1.9 and for GCS 81.9 ± 1.5. The area under ROC is 0.86 ± 0.02 in the APACHE II; 0.85 ± 0.06 in the MEES and 0.88 ± 0.03 in the GCS. There was no statistical differences among APACHE II, MEES and GCS in terms of correct prediction outcome. Youden index and the area under ROC (P < 0.05). Conclusion: APACHE II is not much better than prehospital descriptive scoring system (MEES and GCS). APACHE II and MEES may not replace the role of GCS in the prediction mortality in nontraumatic coma. For the assessment of mortality the GCS score provides the best indicator for these patients (simplicity, less time-consuming and effective information, especially in an emergency situation). P251 Application of prognostic score to patients following cardiac arrest MV de la Torre-Prados, A García-Alcántara A, A Poullet-Brea, C Reina-Artacho and A Soler-García Servicio Medicina Intensiva HU Virgen de la Victoria, 29016-Málaga, Spain Crit Care 1999, 3 (suppl 1):P251 Introduction: The use of prognostic scores in continuous form may help in decision-making in the post-resuscitation phase following cardiac arrest. Objective: To evaluate the clinical efficacy of a prognostic score [1] on intrahospital mortality of patients suffering extrahospital cardiac arrest. Material and method: A 6 month prospective study carried out on 37 patients in the Emergency Unit of a 650 bed hospital (attending to a total of 74 000 patients per year). A score of 0–6 based on cardiac rhythm at time of arrest was applied (cardiac rhythm different to ventricular tachicardia without pulse or ventricular fibrillation = 3). Glasgow score at the time of admission (4 or 5 = 1 and 3 = 2) and type of cardiopulmonary resuscitation received up to arrival of Emergency Assistance (no first aid from qualified personnel at time of arrest = 1). Results: Average age was 61.8 ± 14.9 years (29–84), with sex distribution of 59.4% male and 40.5% female. Conclusion: 1 The application of this score may prove useful in clinical practice to evaluate the continuity of life-support. 2 Neurological assessment is the most valuable clinical variable for prognosis in the follow-up phase. 3 As in other studies, age is not a determining factor in intrahospital mortality following cardiac arrest. 4 Median arterial pressure shows a difference of some 20 points between the surviving and non surviving groups. 5 Mortality among males is significantily greater than females after receiving CPR. 6 The type of assistance received prior to arrival of health services is of significant value in the survival chain. 1. Lancet 1995, 346:417-421. MAP, Median arterial pressure hospital admisssion. *Significant difference between groups, Chi Square. **t test. P252 Outcome of children with near drowning requiring treatment in PICU P253 Prognosis related to organ dysfunction in intensive care unit D Gionis, M Moustaki, Z Beka, A Tsoutsou, E Ourani and J Papadatos ‘P&A Kyriakou’ Children’s Hospital, PICU Crit Care 1999, 3 (suppl 1):P252 A number of near drowned children needed admission to a PICU due to the severity of their condition. The aim of this review is to illustrate the epidemiology, the clinical features, the management and the outcome of near drowned children admitted to our PICU. For this purpose, we reviewed the charts of near drowned children admitted to our unit during the last 11 years. The study population consisted of 11 children (7 boys and 4 girls) aged 2.5–12.5 years (mean age 7.2 years, SD4,1, SE1.3). At the same period a five-fold number of near drowned children were hospitalized in pediatric wards. The submersion site, among our patients, was sea in 6 cases, a swimming pool in 3, a pond in 2 cases. Ten children were transferred from district hospitals where they had initially received advanced life support. 6/10 children were transferred intubated. 4/10 children were in cardiac arrest after the accident, 3/4 had been given basic life support at the accident site and subPS Martins and S Blecher Hospital Santa Marcelina, São Paulo, Brazil Crit Care 1999, 3 (suppl 1):P253 Objective: To develop a model for assessing severity of organ dysfunction (OD) among patients on the first 24 h of Intensive Care Unit (ICU) stay, using a score to determine the probability of ICU mortality. Design: Prospective cohort study. Setting: General medical and surgical ICU in a tertiary teaching hospital in City of São Paulo, Brazil. Patients: Three hundred and seventy-eight consecutive, unselected patients over the period from March to October of 1996: developmental sample. Three hundred patients over the period from February to June of 1997: validation sample. Outcome measure: Patients vital status at ICU discharge. None intervention was considered. Statistical analysis: APACHE II score was calculated for all patients. A Lowess Regression model, using the variables that demonstrated P £ 0.10 in the univariate analysis was made to idenARF, Acute renal failure sequently 2 of them were intubated on their arrival at the nearest district hospital. 1/4 was intubated in the nearest hospital where he was transferred with brain death without having received appropriate basic life support for about 30 min. 2/3 children who initially were apnoeic and comatose, required intubation. The remaining 4 children had respiratory distress and irregular respiration but only one needed intubation. 8/11 patients have clinical and roentgenographic features of pulmonary oedema. The intubated children remained on mechanical ventilation from 12–36 h. Convulsions occurred in 3 children. In 1/11 patients there were signs of high intracranial pressure with good response to mannitol administration. 10/11 patients survived and discharged from hospital after 3–6 days of hospitalization overall. The patient who was admitted with brain death, never recovered. All survived children had no neurological sequalae on their follow up 2–5 years later. Our results emphasize that even the most severe cases of near drowning have a favorable outcome, provided that the victims are given basic life support at the accident site. tify the level of severity of each variable. The variables were then entered into a multiple logistic regression analysis resulting in a probability of ICU mortality equation. The Goodness-of-fit test was used to evaluate model calibration; discrimination was evaluated using area under the receiver operating characteristic curve (ROC), in the developmental and validation samples. Main results: OD was considered in five systems: neurologic, pulmonary, renal, cardiovascular and hematologic, plus the presence of chronic disease. The points were assigned from 1 to 4 according to the levels of severity (Table). The results showed good calibration (P = 0.96; C = 2.33; dF = 8 and P = 0.90; C = 3.01; dF = 10) respectively in the developmental and validation samples, and good discrimination (ROC curve of 0.81 and 0.82, respectively). Conclusion: Cardiovascular dysfunction was the most severe organ dysfunction, followed by pulmonary, renal and neurologic dysfunction. Hematologic dysfunction and the presence of chronic disease were less severe. This model can be used as end point in epidemiologic studies of organ dysfunction in our ICU when the points are summed according to the horizontal lines (severity within an organ system), or as a predictor of death when the points are summed vertically, once the b is the same for all variables. P254 Characteristics of patients with sepsis and multiple organ failure in the UK L Shaikh, H Stuart, A Rhodes and RW Chang for the RIP Users Group Dept of Intensive Care, St George’s Hospital, London, SW17 0QT, UK. Fax 0181 7679748 Crit Care 1999, 3 (suppl 1):P254 All severe sepsis and multiple organ failure patients Introduction: This study examined the characteristics and ICU outcome of patients admitted with severe sepsis and compared them with patients who develop severe sepsis after admission to the ICU. Method: The Riyadh Intensive Care Program (RIP) database 1989–1996 contains 28 094 complete demographic data, daily APACHE II and TISS scores from 21 UK ICUs. 2790 patients retrospectively satisfied the criteria of severe sepsis and multiple organ failure. Results: See Table. Conclusion: The timing of development of severe sepsis and multiple organ failure appears to be an important factor for outcome with a significantly higher mortality among those admitted with sepsis. The admission APACHE II score and the score on the day of development of sepsis were lower among those who developed sepsis. This may be attributable to these patients already being in the ICU environment and thus receiving closer monitoring and more timely intervention. This finding may be of importance in the design of future trials to evaluate new treatment modalities. Apache II on 1st day of sepsis (SD) 1162 (41.6%) 1628 (58.4%) 60.2 (16.7) 58.5 (17.7) 61.5 (15.9) <0.001 23.2 (7.5) <0.001 24.7 (7.2) <0.001 2.4 (0.7) <0.001 Differences between those admitted with and those that developed sepsis Admission Apache II (SD) Day of sepsis Apache II(SD) 25.8 (7.2) No organ failure (SD) L Shaikh, H Stuart, A Rhodes and RW Chang for the RIP Users Group Dept of Intensive Care, St George’s Hospital, London, SW17 0QT, UK. Fax 0181 7679748 Crit Care 1999, 3 (suppl 1):P255 Introduction: No large, well-controlled, trial has been able to demonstrate a statistically significant and reproducible benefit of experimental treatment in severe sepsis and multiple organ failure. This study was done to determine the factors that have to be controlled for in future design of clinical trials in sepsis. Method: 2790 patients from the RIP database satisfied the criteria of severe sepsis and multiple organ failure. Logistic regression APACHE II Score Number of organ failures APACHE II Score APACHE II Score APACHE II Score Poster abstracts 127 analysis was carried out to determine the factors that influenced ICU outcome. The CHAID model of an expert system AnswerTree (SPSS, UK) was also used to derive decision rules that govern the outcome of these patients. Results: Of the eight independent variables entered into the logistic regression analysis four in order of importance were selected: APACHE II score on the day of development of sepsis, treating centre, number of organ failures, age. The area under ROC was 0.75. The level and branches of the decision rules by the expert system is shown in the Figure on the previous page. The difference in outcome for all the nodes is P < 0.0001 Conclusion: As the area under the curve of the ROC = 0.75, one is unlikely to use logistical regression analysis to risk stratify patients for future trials of severe sepsis; however, expert systems can delineate statistical significance and patterns which influence outcome in a complex trial population. P256 Does SOFA and TISS scores correlate in long term ICU patients? I Novak, P Hora, M Bilek, M Suchy, R Rokyta and V Sramek ICU, Medical Dpt I, Charles Uni Hospital Plzen, Alej Svobody 80, CZ-30466 Plzen, Czech Republic. Tel: +420-19-710 3 165; Fax: +420-19-522 566; E-mail: Crit Care 1999, 3 (suppl 1):P256 Introduction: SOFA score is a useful tool for monitoring of organ function in ICU patients [1]. TISS score is used for measuring of workload in intensive care [2]. We studied if there is any link between SOFA and TISS scores in long term ICU patients (i.e. patients staying in the ICU >3 days). Materials and methods: Daily SOFA and TISS scores of ICU patients admitted between July and November 1998 who stayed in the ICU >3 days were retrieved from data collection system. An experienced ICU doctor has collected SOFA scores into this system daily. Pooled scores for the whole group, for ICU survivals (S) and nonsurvivals (NS) separately and the scores on the first day of ICU stay were analysed. Results: Sixty-two patients (i.e. 42% out of total admissions; age 60.0 ± 14.7 years) fulfilled the inclusion criteria and stayed in the ICU for the mean of 11.9 ± 10.8 days). ICU mortality was 30.6% (19 patients). Significant correlation was found for pooled SOFA and TISS scores (r2 = 0.52, P < 0.0001) and it was more pronounced in survivals (S) than in nonsurvivals (NS) (r2 = 0.52, P < 0.0001 and r2 = 0.19, P < 0.0001, respectively). Significant link between the two scores was already present on the first day of ICU stay (r2 = 0.54, P < 0.0001). Conclusion: In long term ICU patients a significant correlation is present between organ failures (scored by SOFA) and workload (measured by TISS). This link is already present on the day of admission and later on is more pronounced in survivals possibly because in NS the care is more often witheld or withdrawn. References 1. Vincent JL et al.: Use of the SOFA score to assess the incidence of organ dysfunction/failure in the intensive care units: Results of a multicenter, prospective study. Crit Care Med 1998, 26:1793-1800. 2. Dickie H et al.: Relationship between TISS and ICU cost. Intensive Care Med 1998, 24:1009-1017. P257 Daily SOFA scoring for ICU patients? P Hora, M Bilek, M Suchy, R Rokyta, I Novak and V Sramek ICU, Medical Dpt I, Charles Uni Hospital Plzen, Alej Svobody 80, CZ-30466 Plzen, Czech Republic. Tel: +420-19-710 3 165; Fax: +420-19-522 566; E-mail: Crit Care 1999, 3 (suppl 1):P257 Introduction: SOFA might be a useful tool for monitoring of organ function in ICU patients [1]. We evaluated optimal frequency of SOFA acquisition in long term ICU patients (i.e. patients staying in the ICU >3 days). Materials and methods: Daily SOFA scores of ICU patients admitted between July and November 1998 who stayed in the ICU >3 days were retrieved from the data collection system. An experienced ICU doctor has collected SOFA scores into this system daily. Original daily SOFA score flow charts and adapted (simplified) SOFA score flow charts (SOFA on days 1, 4, 7, 10, 14, 21, 24, 28 etc.; i.e. values of unlisted days expressed as trends between data collection days) were compared for individuals and the whole group of patients. Data are presented as means ± SD; P < 0.05 was considered significant. Results: Sixty-two patients (i.e. 42% out of total admissions; age 60.0 ± 14.7 years) fulfilled the inclusion criteria and stayed in the ICU for the mean of 11.9 ± 10.8 days. ICU mortality was 30.6% (19 patients). Original and adapted data did show equal values for the whole group of patients (MANOVA group by time effect 0.98 at Day 4, 62 patients and 1.00 at Day 7, 36 patients). Out of total 736 ICU days, in 374 there was theoretical possibility of data difference (adapted SOFA scores). Significant difference (defined as DSOFA >2) between original and adapted values was found in 64 cases (17.1%) In 30 cases adapted values were higher then original ones. Conclusion: SOFA score collected 2–3 times a week describes sufficiently characteristics of long term ICU patients. Significant individual data might be lost when SOFA score is not collected on daily basis. U Janssens, C Graf, J Graf and P Hanrath Medical Clinic I, University Hospital of RWTH Aachen, Pauwelsstraße 30, D-52057 Aachen, Germany Crit Care 1999, 3 (suppl 1):P258 Objectives: The SOFA (sepsis-related organ failure assessment) score describes quantitatively the degree of organ dysfunction. Although primarily not designed to predict outcome any assessment of morbidity must be related to mortality to some degree. We therefore investigated whether an increasing SOFA score is associated with a higher hospital mortality in patients (pts) of a medical intensive care unit (ICU). Methods: All consecutive pts who stayed >24 h in ICU were included in this prospective study between 11/97 and 2/98. SOFA score and SAPS II were determined after 24 h. Discrimination power of the scores for survivors (S) and non-survivors (NS) [hospital mortality] was assessed by the area under the Receiver Operating Characteristic (AUROC) curve. Results: 303 pts (216 male [71.3%], 62 ± 12 years, length of ICU stay 3.7 ± 4.7 days, SOFA 2.5 ± 2.9, SAPS II 26 ± 12.6) were studied. Hospital mortality was 14.5%. SOFA score for NS was significantly higher than for S (5.9 ± 3.7 vs. 1.9 ± 2.3, P < 0.05). The AUROC was 0.82 ± 0.04 for the SOFA score and 0.77 ± 0.04 for SAPS II. P259 Statistical modeling of prognostic indices Figure. Mortality (%) versus SOFA score. Conclusion: SOFA score discriminates well between S and NS 24 h after admission. Respiration, liver and coagulation showed an increasing mortality rate with a higher SOFA score for each organ. Although the SOFA score was primarily designed for use in septic patients it may be also applied for pts of a medical intensive care unit. J Livianu, S Blecher, JMC Orlando and JO Proença Hospital Municipal Jabaquara-Rua Francisco Paula Ribeiro 562, São Paulo, Brazil Crit Care 1999, 3 (suppl 1):P259 Introduction: Severity scoring models can provide accurate outcome prediction but their performance is very influenced by variations in patient case-mix. Therefore, none of the usual scoring systems (APACHE II, SAPS II and MPM 24) fitted to this ICU: they had good discriminatory power but poor calibration. Logistic regression analysis of their variables was performed to identify the most predictive association to ICU mortality. Methods: Data of 823 consecutive patients (pts) admitted to the ICU were prospectively collected. Pts who stayed less than 24 h at the ICU or were burn or had less than 16 years old were excluded. For pts with several admissions, only the first ICU admission was considered. The remaining 709 pts were divided in two groups: 418 (59%) pts constituted the development set and 291 (41%) pts became the validation set. After calculating the scoring indices, their variables and respective weights were separately analysed. Variables with P value <0.05 at univariate analysis were included as independent variables at logistic regression and vital status at ICU discharge was considered as dependent variable. Results: There were 67% male and 33% female pts; median age was 46 years old, postoperative care took up 330 (46.7%) cases, of which 275 (83%) were emergency surgery. Trauma was the admission cause for 200 (28%) pts. ICU mortality rate was 25.1% and APACHE II, AII; SAPS II, SII; MPM 24, M24, OR, odds ratio Glasgow coma scale Temperature WBC count Infection present Serum creatinine Urine output Points assigned as hospital mortality 33.7%. APACHE II was 16.7 ± 8.4 and SAPS II was 33.5 ± 16.5. Through statistical modeling, an hibrid model was generated, with variables and points from the three indices. With this model, the prediction obtained was: development set with discrimination ROC = 0.89 and calibration goodness-of-fit C = 1.68 and validation set with ROC = 0.84 and goodness-of-fit C = 7.72. Conclusion: Hemodynamic instability, infection, impaired renal function, respiratory failure and coma were the best predictors of death. Early identification of patients at major risk may allow treatment with more resources and interventions, in order to improve survival. Furthermore, this study shows that suitable statistical management may be useful to customize and enhance the prognostic accuracy of the currently available scoring systems. P260 The determination of the duration of the nursing activities in the intensive care unit and the therapeutic intervention scoring sysem (TISS) N Kýlýçaslan and G Kocaman Dokuz Eylül University School of Medicine, Ýzmir, Turkey Crit Care 1999, 3 (suppl 1):P260 The purpose of this study was to calculate nurse/patient radio by using TISS-28, and to assess time allocation to nursing activities in the intensive care unit. In this study the TISS scores of 416 patients were calculated in the intensive care unit 10 weeks long using the TISS-28 form. In order to determine the duration of the nursing care activities due to nursing care categories the work sampling method was used. A sampling matrix for 10 weeks was created and the nursing care activities were observed 7 days a week for two day shifts (08.00–16.00). The data collection instruments were, the ‘TISS-28’ and ‘Work sampling form for intensive care unit nursing activities’. The TISS-28 point for ICU was 40.41 for day shift. One TISS-28 point equals 11.88 min of the 480 min in each shift. Related literature shows that nursing care activity for one day makes 40–50 TISS score. The percentage of nursing time spent on nursing activities in the ICU was calculated by using work sampling. Results indicated that 44.25 % of nurses time was spent in activities in TISS-28; 12.87% in activities not in TISS-28; 25.8% in indirect patient care, 6.21% in organnizational activites, 10.64% in personnel activities and 0.15% in other activities. It is shown that category one represents TISS-28 and that the increase in TISS score results in the increase in nursing care activity duration. These result show that the TISS-28 can be useful to determine the patient/nurse ratio in intensive care units. References Miranda DR, Rijk AD, Schaufeli W: Simplified Therapeutic Intervention Scoring System: The TISS-28 items: results from a multicenter study. Critical Care Medicine 1996, 24:64-72. Cullen DJ, Cývetta JM; Briggs BA: Therapeutic Intervention Scoring System: a method for guantitative comparison of patient care. Crit Care Med 1974, 2:57. Hendrickson G, Doddato T, Kovner C: How do nurses use their time? JONA 1990, 20:3. Urden DL, Roode JL: Work sampling (a decision-making tool for determining resources and work redesigning). JONA 1997, 27:34-41. P261 Fast-track intensive care procedure after cardiac surgery in the 9th decade N Huebner, W Rees*, M Boeckelmann, S Rittel*, H Warnecke* and U Christmann Dept. Anesthesiology, *Dept. Cardiac Surgery, Schuechtermann Klinik, Ulmenallee 11, 49214 Bad Rothenfelde, Germany Crit Care 1999, 3 (suppl 1):P261 Objective: Outcome with fast track intensive care medicine after cardiac surgery in patients older than 80 years. Methods: Between 7/96 and 7/97, 86 cardiac operations (3.7%) have been performed in patients older than 80 years out of an overall number of 2349 cardiac operations. Preoperative NYHA Status was III in 36.1% and IV in 46.5% of the old patients. LVEF was 49%, LVEDP 16 mmHg. Additional desaeses were: diab. mell. 23.3%, renal insufficiency 11.6%, cerebral stroke 10.5% and myocardial infarction 37.2%. Performed cardiac operations have been: CABG (61.6%), AVR (23.3%), CABG and AVR (12.8%), MVR (1.2%), CABG and MVR (1.2%) and REDO operations (4.6%). Mean time on ECC was 84 min and overall operation time was 169 min (mean). Anesthesia was conducted as balanced anesthesia with early extubation as a main aim. Results: Patients were extubated 6 h ( median ) after surgery, shortest duration of ventilation was 30 min. Mean stay on ICU was 2.6 days and mean time of hospitalisation was 9.4 days. 30-day-mortality was 3.4% in the old patients and 2.2% in the overall population. Conclusion: Fast-track procedure after cardiac surgery in the octanarian is feasible with even better results and without any additional risk than conventional intensive care procedure. P262 Prognosis and functional capacity a year after a myocardial infarction on elderly 80-year-old patients L Lorente, M Martin, R Medina, JJ Valencia, J Mujika and A Jimenez Intensive Care Unit, Clinica La Colina, Santa Cruz de Tenerife, Spain To analyse differences between sex, localization and developed or no Q wave. Design: Retrospective analysis. Patients: All patients of ³80 years admitted between 1.1.94 and 31.10.97 with a myocardial infarction. Evaluation of evolution curve: The study was done through telephonic interview. We analysed mortality at the reception (REC), 1, 3, 6, 9 and 12 months (M). Was used a daily activity scale (DAS) with five factors (walking, dressing, bathing, cleaning and eating) with a punctuation from 0 to 2 every activity (0 = total dependence, 1 = partial dependence and 2 = independence), with a range 0 to 10. Statistical analysis: The statistical significance of the variables was tested by Fisher’s test of t Student test. Values less than 0.05 were considered statistically significant. Results: We included 112 patients, 54 (48.21%) male and 58 female. The localization of the myocardial infarction was anterior (Anter) in 71 cases (63.39%) and inferior (Infer) in 41, and 87 patients (77.67%) developed Q wave. At the reception 41 (36.60%) patients dead and 16 patients dead at the following 12 months (accumulated mortality at year = 50.89%). Q wave and anterior myocardial infarction had more mortality, with P < 0.001 and P < 0.05 respectively. At year, the survivors had a mean DAS 8.72 ± 1.89. It was higher in non-Q wave (P < 0.05) and males (P < 0.05). The evolution is shown in the Table. Conclusion: Though the mortality between elderly 80 years old patients with myocardial infarction is high, they have an acceptable functional capacity (more in males and non-Q-wave myocardial infarction). Patients with MI P263 Very old patients (older than 85 years) at a medical ICU: indications, interventions, outcome J Reiger and G Grimm IInd Medical Department General Hospital, A-9020 Klagenfurt, St. Veiterstrasse 47, Austria Crit Care 1999, 3 (suppl 1):P263 Objective: The part of elderly people in the population has been increasing during the last decades. In 1995, 16% of the MiddleEuropean population have been older than 65 years, up to the year 2010 there should be an increase up to 22%. German investigations have shown, that a 1/3 of the population older than 65 years are suffering from 3–4 chronic diseases, 98% of the population older than 80 years from one chronic disease. Through those facts the number of old patients admitted to ICUs is increasing. Aim of following paper was to objective the treatment and outcome of very old patients (over 85 years) at a medical ICU of a general hospital over an 18-month period (1997-01-01 to 1998-06-30). Results and outcome: 899 patients had been admitted to the ICU during the study period, 48 (5.3%) older than 85 years. At admission the APACHE II-score ranked between 19 and 32. Indications had been mainly cardial (27), metabolic (8), gastrointestinal (6), outside CPR (5) and acute respiratory failure (2). 11 patients had been mechanical ventilated (1–8 days, mean 2.7 days), 6 patients received a cardiac pacemaker, 5 underwent endoscopical interventions, 4 thrombolysis (AMI, 100 mg Alteplase ‘front loaded’), 2 patients PTCA/IABP and one female patient ACBG. Duration of stay had been 3.8 days (overall 3.9 days), mortality 27.7% (overall 14.8%). Conclusion: Comorbidity and mortality had been higher in patients older than 85 years compared to all patients. 6 month after the ICU stay 24 patients (68.5%) were still alive. With good quality of life. Despite higher mortality very old patients benefit from ICU stay and interventions. P264 Quality control with autopsy on a medical intensive care unit J Roosen, E Frans, A Wilmer, S Vanderschueren and H Bobbaers Department of Medical Intensive Care, U.Z. Gasthuisberg, Leuven, Belgium Postmortem examination is considered as the golden standard for the evaluation of clinical diagnosis. However due to several reasons (costs, permission of family members), few medical centers continue to perform autopsy as a means of quality control. From 1995 to 1996, we performed an autopsy study in a medical intensive care unit of a university hospital: 93% of the 140 deceased patients in our medical ICU underwent an autopsy, 100 consecutive patient files were studied. The clinical diagnosis were made by internists, specialized in intensive medicine; the diagnosis on autopsy were made by a pathologist. According to the criteria of Goldman[1], the clinical and autopsy findings were categorized into major and minor diagnoses. A missed diagnosis on clinical grounds was classified as a class I error (if detected before death, this would probably have caused a therapeutic change with possible altered outcome) or as a class II error (if known before death, this diagnosis would not have led to a change in therapy). In 16% of the patients, a class I missed diagnosis was detected (cardiac tamponade, myocardial infarction, fungal pneumonia); in 9%, a class II missed diagnosis was detected (most frequently tumors). Sometimes the diagnosis was missed due to a combination of severe, acute problems (e.g. development of cardiac tamponade after insertion of a venous catheter during hemorraghic shock), or due to a lack of sensitive and specific investigational methods (fungal pneumonia is frequently suspected in immunocompromised patients, but is often difficult to confirm), or due to logistic transportation problems in the hemodynamically unstable patient (e.g. retroperitoneal hemorrhage is not always detectable on bedside echography; for diagnosis, CAT-scan is needed). Conclusion: Even in the era of increasing diagnostic possibilities, due to improved medical technologies in the ICU, postmortem examination still remains useful in detecting unexpected diagnoses, missed in the premortem clinical evaluation. Our observations suggested the need for constant alertness and an aggressive investigational planning in patients with unexplained shock or pulmonary infiltrates. P265 Quality of life before and after medical intensive care M Wehler, R Strauß, A Bost, A Geise, A Müller, M Meyer* and EG Hahn Department of Medicine I and *Institute of Medical Statistics and Documentation, University of Erlangen-Nuremberg, 91023 Erlangen, Germany Introduction: We prospectively analysed changes in the quality of life (QOL) in patients before and 6 months after admission to a medical intensive care unit (ICU). Patients and methods: All patients admitted to the ICU were eligible for inclusion. Patients <18 years and those who died or were discharged within 24 h of admission were excluded, QOL measures were collected during interview during the first 24 h of ICU stay and 6 months after admission using a questionnaire especially designed for ICU patients developed by the Spanish Group for Epidemiological Analysis of Critical Care Patients [1]. Baseline QOL referred to the 2 months prior to admission and were compared with measures at 6 months using Wilcoxon matched-pairs test, P < 0.05 was considered statistically significant. Results: During the first 12 months of the study period 326 patients met the study criteria; mean age was 58 ± 17 (± SD) years, median 60, range 19–95 years, 55% were male. Mean ICU length of stay was 10.4 ± 15.1 days, range 2–127 days. Mean APACHE II score was 23 ± 10, range 0–51. Mean TISS score after 24 h was 33 ± 14, range 0–69. Mortality rates were: ICU 24%, hospital 6%, 9% within the following 6 months after hospital discharge. Up to now 147 patients completed the questionnaire after 6 months, six patients (1.8%) were lost to follow-up. Relative to baseline a significant worsening was noted in the subscale of normal daily activities (P = 0.013). No significant changes were seen in total QOL score (P = 0.25) an the subscales of physiologic basic activities (P = 0.06) and emotional state (P = 0.09). No correlation existed between APACHE II scores and QOL (r = 033). Conclusion: Six months after ICU treatment patients had a significant decrease in the level of their daily activities. Basic physiologic activities and emotional status are not significantly altered. 90% of the long-term survivors were living at home and all previously occupied patients were able to return to their previous profession. Reference 1 Fernandez RR, et al.: Intens Care Med 1996; 22:1034-1042. P266 Withdrawal of intensive care in the patient’s home P Williams and S Mann ICU, Middlemore Hospital, Otahuhu, Auckland, New Zealand Death should be managed as vigorously as life saving. Historically intensive therapy is withdrawn in the intensive care unit, but we would like to present four cases where intensive care treatment was withdrawn at home. The staff of the Intensive Care Unit at Middlemore Hospital have taken four patients home, on ventilatory and inotropic support, and withdrawn care when the patient was settled in their home, surrounded by family. This is felt to aid in the grieving process, and in many cases is culturally desirable. The cases thus far are subarachnoid haemorrhage, massive intracerbral bleed and intractable septic shock. From our experience we recommend that certain selection criteria are observed. There is a need for the patient and family to live locally, support is required from the local general practitioner and district nursing service, and a clear explanation of the whole process must be understood by all family members prior to leaving the intensive care unit. A palliation plan must be commenced prior to leaving the intensive care unit. RJ McRae Dept Anaesthesia & Pain Management, The Alfred, Commercial Road, PRAHRAN, VIC, Australia, 3181. Tel: 613 9276 2851; Fax: 613 9276 2813; E-mail: Crit Care 1999, 3 (suppl 1):P267 Three hundred and sixty-seven (67%) of questionnaires on ethical issues distributed to members of the Australian and New Zealand Intensive Care Society were returned and included for analysis. The questionnaire was similar to a questionnaire that had been distributed to members of the European Society of Intensive Care Medicine, but adapted and augmented for local use, and provides a useful comparison of how issues are considered in Australasia. Intensive Care beds are a limited resource, and availability restricts admissions. Nonetheless, 76% of respondents admitted patients with a poor prognosis for survival. There was high (82%) concordance of what was felt should be done and what was done in clinical scenarios. Respondents considered that they provided high information to patients, including in the event of iatrogenic complication. In terms of end-of-life decisions, 35% of respondents wrote that they would involve the family in discussions (not an option available for selection): this appeared to be a pragmatic approach to dealing with relatives. Withdrawal of treatment was considered to be different to withholding treatment by 43% of respondents. 34% of respondents would change a do-not-resuscitate order that had been previously instituted. 15% of respondents considered that an Ethics Consultant would assist in their practice, with 95% supporting the inclusion of ethics teaching during medical training. P268 Withholding and withdrawing life support: national French prospective study E Ferrand, R Robert, P Ingrand and the LATAREA group Service de Réanimation Médicale CHU, Poitiers 86021 Poitiers cedex, France Introduction: Controversies still exists regarding indications of WH and WD, ethical similarity or difference between WH and WD, the way to withhold or to withdraw treatments and what should be the family implications in these decisions were older and had higher SAPS 2 than the remaining patients. Decisions of withhold or withdraw were more frequent in patients with previous chronic diseases or cardiac arrest before admission in ICU. Futility and the poor expected quality of life were the most frequently cited reason for WH or WD. Decision to not ventilate the patient was the most frequently reported withheld treatment (n = 214; 15%). Vasopressors were either not started or limited in their dosage in 196 patients (14%). The most frequently withdrawn life support treatment were vasopressors (19%). Extrarenal epuration was discontinued in 67 patients (7%). Lowering FiO2 to 21% was indicated in 155 patients (14.5%), discontinued ventilation was ordered in 101 patients (9.4%) and extubation was performed only in 34 patients (3.1%). Withdrawal of hydration was rarely performed (n = 16 ; 1.5%). 1176 out of the 7309 (16.1%) included patients died. 628 out 1176 died (53%) after support was withheld or withdrawn. Most of the time WH or WD was decided by the medical team. A unique M.D. was involved in the decision in 37 (12%) of cases. Paramedic (nurses) opinions was taken in account for the decision in 482 (59.7%). Family was involved in the process in less than 50%. Results: Treatments were withheld or withdrawn in 807 out 7309 (11%). WH and WD were indicated in 336 patients (4.6%) and 471 patients (6.4%) respectively. ICU patients undergoing WH or WD 1. Goldman L , Sayson R , Robbins S et al.: The value of the autopsy in three medical eras . N Engl J Med 1983 ; 308 : 1000 - 1005 . P267 Results of an ethical questionnaire distributed to members of the Australian and New Zealand Intensive Care Society

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JM Constantin, G Gindre, JD Segrell-Therre, JE Bazin, P Schoeffler. Determination of the best volume of perfluorocarbone to ensure partial liquid ventilation in the pig with ARDS, Critical Care, 2000, P041,