Improved ROSC rates in out-of-hospital cardiac arrest patients after introduction of a text message alert system for trained volunteers

Original Article Neth Heart J https://doi.org/10.1007/s12471-021-01656-6 Improved ROSC rates in out-of-hospital cardiac arrest patients after introduction of a text message alert system for trained volunteers D. M. Oosterveer · M. de Visser · C. Heringhaus Accepted: 17 November 2021 © The Author(s) 2022 Abstract Objective To evaluate whether a text message (TM) alert system for trained volunteers contributed to early cardiopulmonary resuscitation, the use of automated external defibrillators (AEDs), return of spontaneous circulation (ROSC) and survival in out-ofhospital cardiac arrest (OHCA) patients in a region with above-average survival rates. Design Data on all OHCA patients in 2012 (non-TM group) were compared with those of all OHCA patients in 2018 (TM group). The association of the presence of a TM alert system with ROSC and survival was assessed with multivariate regression analyses. Results TM responders reached 42 OHCA patients (15.9%) earlier than the first responders or ambulance. They connected 31 of these 42 OHCA patients (73.8%) to an AED before the ambulance arrived, leading to a higher percentage of AEDs being attached in 2018 compared to the 2012 non-TM group (55% vs 46%, p = 0.03). ROSC was achieved more often in the TM group (61.0% vs 29.4%, p < 0.01). Three-month and 1-year survival did not differ significantly between the two groups (29.3% vs 24.3%, p = 0.19, and 25.9% vs 23.5%, p = 0.51). Multivariate regression analyses confirmed the positive association of ROSC with the TM alert system (odds ratio 1.49, 95% confidence interval 1.02-2.19, p = 0.04). Conclusion A TM alert system seems to improve the chain of survival; because TM responders reached patients early, AEDs were attached more often and more OHCA patients achieved ROSC. However, the introduction of a TM alert system was not associated with improved 3-month or 1-year survival in a region with above-average survival rates. Keywords Cardiac arrest · Bystander cardiopulmonary resuscitation · Utstein template · Resuscitation · Survival Introduction Survival rates following an out-of-hospital cardiac arrest (OHCA) are poor throughout the world [1]. To maximise survival in OHCA patients, a chain of survival was introduced at the 1992 National Conference on Cardiopulmonary Resuscitation and Emergency Cardiac Care [2]. The chain consists of four links: What’s new? A text message (TM) alert system has benefits even in regions with already above-average survival of out-of-hospital cardiac arrest (OHCA) patients.  Since the introduction of the TM alert system more automated external defibrillators have been attached to OHCA patients and return of spontaneous circulation has been achieved more often.  No improvement in survival at 3 months or 1 year was found.  D. M. Oosterveer () Basalt Rehabilitation Centre, Leiden/The Hague, The Netherlands M. de Visser Department of Research and Development, Hollands Midden Regional Ambulance Service, Leiden, The Netherlands M. de Visser · C. Heringhaus Emergency Department, Leiden University Medical Centre, Leiden, The Netherlands Improved ROSC rates in out-of-hospital cardiac arrest patients Original Article early access to the emergency medical services system, early cardiopulmonary resuscitation (CPR), early defibrillation and early advanced care. For the ambulance services of the Hollands Midden region (RAVHM) in the mid-west of the Netherlands specific measures were introduced to optimise this chain of survival: police and fire departments were equipped with automated external defibrillators (AEDs) and officers were trained to perform adequate basic life support as first responders. Bystanders were supported by the dispatch centre in starting CPR. The ambulance staff perform CPR using a mechanical chest compression device, the Lund University Cardiopulmonary Assist System (LUCAS; Jolife AB, Lund, Sweden) and the Boussignac tube (Vygon, Ecouen, France) as the preferred assistive devices. These optimisations in the chain of survival have led to an improvement in the number of patients with return of spontaneous circulation (ROSC) on arrival at the emergency department of the hospital as well as in the 1-year survival rate in the region served by the RAVHM as compared with the data for 2012 [3]. To further optimise the chain of survival in this region, a national text message (TM) alert system was implemented in 2016. This system alerts local lay responders to perform CPR or directs them to a nearby AED first [4]. Other studies have shown that a TM alert system can diminish the time to first shock and that this reduced delay is correlated with the availability of more TM responders and increasing density of AEDs [4, 5]. A Dutch study found higher survival rates in patients when a TM responder arrived at the scene [6]. A recent meta-analysis confirms the positive influence of a TM alert system, but also notes that no long-term survival data are available [7]. In addition, there are no outcome data of OHCA patients before and after the introduction of a TM system in a region in which survival is already above average, such as ours [3, 8]. This retrospective observational study compares the survival rate in OHCA patients in 2012, i.e. before the introduction of the TM alert system, with that of OHCA patients in 2018, 2 years after the introduction of this system. In addition, we investigated how often a TM responder reached OHCA patients earlier than regular emergency services and how often a TM responder attached an AED before the arrival of the emergency services. Methods Setting The RAVHM provides ambulance services for approximately 775,000 inhabitants in the mid-west region of the Netherlands. Mean response time in 2012 was 9 min 59 s, in 2018 10 min 9 s (data from the validated time-keeping system OpenCare Ambu V.1.10/1.11; Centric, Gouda, The Netherlands). Improved ROSC rates in out-of-hospital cardiac arrest patients When the dispatch centre is called for a (suspected) OHCA, two ambulances drive to the scene. First responders (i.e. policemen and firemen) are notified as well when they are in close proximity to the OHCA patient. Since 2016 the dispatch centre of the study region has activated the TM alert system simultaneously with sending two ambulances: TM responders within a range of 750 m of the OHCA patient receive a text message on their cell phone directing them to the patient or to the location of the nearest AED first if available within a range of 500 m. All TM responders receive annual training from professional trainers in providing CPR. In 2018, there were 2.5 TM responders/km2 and 0.6 AEDs/km2. Study population For the baseline population before the introduction of the TM alert system (the non-TM group) we used the study population of a previous observational prospective study [3]. These patients were included between November 2011 and 4 April 2013. For the population after the introduction of the TM alert system (the (...truncated)