Acute Kidney Injury Enhances Outcome Prediction Ability of Sequential Organ Failure Assessment Score in Critically Ill Patients

et al. (2014) Acute Kidney Injury Enhances Outcome Prediction Ability of Sequential Organ Failure Assessment Score in Critically Ill Patients. PLoS ONE 9(10): e109649. doi:10.1371/journal.pone.0109649 Acute Kidney Injury Enhances Outcome Prediction Ability of Sequential Organ Failure Assessment Score in Critically Ill Patients Chih-Hsiang Chang 0 Pei-Chun Fan 0 Ming-Yang Chang 0 Ya-Chung Tian 0 Cheng-Chieh Hung 0 Ji- 0 Tseng Fang 0 Chih-Wei Yang 0 Yung-Chang Chen 0 Giovanni Camussi, University of Torino, Italy 0 1 Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital , Taipei , Taiwan Chang Gung University College of Medicine, Taoyuan, Taiwan, 2 Chang Gung University College of Medicine , Taoyuan , Taiwan Introduction: Acute kidney injury (AKI) is a common and serious complication in intensive care unit (ICU) patients and also often part of a multiple organ failure syndrome. The sequential organ failure assessment (SOFA) score is an excellent tool for assessing the extent of organ dysfunction in critically ill patients. This study aimed to evaluate the outcome prediction ability of SOFA and Acute Physiology and Chronic Health Evaluation (APACHE) III score in ICU patients with AKI. Methods: A total of 543 critically ill patients were admitted to the medical ICU of a tertiary-care hospital from July 2007 to June 2008. Demographic, clinical and laboratory variables were prospectively recorded for post hoc analysis as predictors of survival on the first day of ICU admission. Results: One hundred and eighty-seven (34.4%) patients presented with AKI on the first day of ICU admission based on the risk of renal failure, injury to kidney, failure of kidney function, loss of kidney function, and end-stage renal failure (RIFLE) classification. Major causes of the ICU admissions involved respiratory failure (58%). Overall in-ICU mortality was 37.9% and the hospital mortality was 44.7%. The predictive accuracy for ICU mortality of SOFA (areas under the receiver operating characteristic curves: 0.81560.032) was as good as APACHE III in the AKI group. However, cumulative survival rates at 6month follow-up following hospital discharge differed significantly (p,0.001) for SOFA score #10 vs. $11 in these ICU patients with AKI. Conclusions: For patients coexisting with AKI admitted to ICU, this work recommends application of SOFA by physicians to assess ICU mortality because of its practicality and low cost. A SOFA score of $ ''11'' on ICU day 1 should be considered an indicator of negative short-term outcome. - Although there are currently numerous co-existing clinical scores for critically ill patients [sequential organ failure assessment (SOFA) [1], Simplified Acute Physiology Score (SAPS) [2,3], Acute Physiology and Chronic Health Evaluation (APACHE) [4 6]], none of them has sufficient accuracy to predict outcome. Raising the sensitivity and specificity and increasing the number of parameters in order to enhance statistical power reduce the simplicity and cost effectiveness for clinical use. Given the aging population and numerous cases of co-morbidity in intensive care unit (ICU) setting today, acute kidney injury (AKI) remains a common and serious complication [79]. Pathophysiological factors associated with AKI are also incriminated in the failure of other organs, indicating that AKI is often part of a multiple organ failure syndrome. The occurrence of individual organ system failures varies among patients admitted to the ICU with AKI, with different degrees of association existing between individual organ system failures and ICU mortality. From this viewpoint, the SOFA score is an excellent tool for assessing the extent of organ dysfunction in critically ill patients with AKI [10,11]. However, there is no extant literature comparing these scoring systems in the setting of AKI defined by the risk of renal failure, injury to kidney, failure of kidney function, loss of kidney function, and end-stage renal failure (RIFLE) classification in critically ill patients [12]. We hypothesized that the discriminative power of the SOFA score in predicting ICU mortality is further enhanced for patients with AKI compared to those without. Therefore, we undertook a post hoc analysis of a prospectively accumulated database, to explore 3 ICU mortality scoring systems (SOFA and APACHE II & III) in critically ill patients with/without AKI and to compare Total (n = 543) AKI (n = 187) Non-AKI (n = 356) Length of ICU stay (days) Length of hospital stay (days) Body weight on ICU admission (kg) GCS, ICU first day (points) MAP, ICU admission (mmHg) Serum creatinine, ICU first day (mg/dl) Arterial HCO32, ICU first day Serum sodium, ICU first day (mg/dl) Bilirubin, ICU first day (mg/dl) Albumin, ICU first day (g/l) Blood Sugar, ICU first day (mg/dl) Hemoglobin, ICU first day (g/dl) Platelets, ICU first day (x103/mL) Leukocytes, ICU first day (x103/mL) PaO2/FiO2, ICU first day (mmHg) ICU mortality (%) Hospital mortality (%) Need for renal replacement therapy (%) Underlying diseases Diabetes mellitus (%) Hypertension (%) Cardiovascular disease (%) Chronic kidney disease (%) Liver disease (%) Malignancy (%) APACHE II, ICU first day (mean 6 SE) APACHE III, ICU first day (mean 6 SE) SOFA, ICU first day (mean 6 SE) RIFLE, ICU first day (mean 6 SE) the scores in these heterogeneous groups in three ICU admission settings. Materials and Methods Study participants and data collection This investigation was carried out at three ICUs of one tertiarycare referral center between July 2007 and June 2008. These ICUs included two medical ICUs and one coronary care unit (CCU). The Chang Gung Memorial Hospital Institutional Review Board approved the study and waived the need of informed consent because there was no breach of privacy and the study did not interfere with clinical decisions related to patient care (approval No. 101-3059B). The patient information was anonymized and de-identified prior to analysis. There were 885 admissions during this period; final diagnosis and admission duration were reviewed first. Patients were excluded if they stayed in the ICU for less than 1 day (n = 89) or had repeated ICU admission (n = 56). Patients under 18 years of age, with organ transplant and end-stage renal disease (ESRD) with long-term dialysis were excluded (n = 154). To determine the ICU outcomes, we also excluded patients admitted to the ICU for observation after invasive procedures (n = 43). Finally, a total of 543 cases were enrolled in this study. Post hoc analysis of a prospectively accumulated database examined the sauop I-onKA ilravv )=266 6..4017 /4792 6..707 6..5213 6..9309 6..7203 6..7143 6..701 6..1304 6..303 6..201 6..2102 6..58862 6..82093 6..0304 6..5416 6..002 ;lscaeM r N Su (n 6 1 8 2 6 1 8 1 2 2 3 1 1 3 1 5 5 a g I K a ftto la ilavv )337 6.09 /82 .06 6.12 6.08 6.02 6.38 .01 6.04 .02 .01 6.02 6..861 6..586 6.04 6.15 .02 .01 rcae ,seq sco tTo rSu (=n .826 812 6.48 .432 .33 (...truncated)