Modifiable Factors Associated With Survival After Out-of-Hospital Cardiac Arrest in the Pan-Asian Resuscitation Outcomes Study.

STUDY OBJECTIVE: The study aims to identify modifiable factors associated with improved out-of-hospital cardiac arrest survival among communities in the Pan-Asian Resuscitation Outcomes Study (PAROS) Clinical Research Network: Japan, Singapore, South Korea, Malaysia, Taiwan, Thailand, and the United Arab Emirates (Dubai). METHODS: This was a prospective, international, multicenter cohort study of out-of-hospital cardiac arrest in the Asia-Pacific. Arrests caused by trauma, patients who were not transported by emergency medical services (EMS), and pediatric out-of-hospital cardiac arrest cases (<18 years) were excluded from the analysis. Modifiable out-of-hospital factors (bystander cardiopulmonary resuscitation [CPR] and defibrillation, out-of-hospital defibrillation, advanced airway, and drug administration) were compared for all out-of-hospital cardiac arrest patients presenting to EMS and participating hospitals. The primary outcome measure was survival to hospital discharge or 30 days of hospitalization (if not discharged). We used multilevel mixed-effects logistic regression models to identify factors independently associated with out-of-hospital cardiac arrest survival, accounting for clustering within each community. RESULTS: Of 66,780 out-of-hospital cardiac arrest cases reported between January 2009 and December 2012, we included 56,765 in the analysis. In the adjusted model, modifiable factors associated with improved out-of-hospital cardiac arrest outcomes included bystander CPR (odds ratio [OR] 1.43; 95% confidence interval [CI] 1.31 to 1.55), response time less than or equal to 8 minutes (OR 1.52; 95% CI 1.35 to 1.71), and out-of-hospital defibrillation (OR 2.31; 95% CI 1.96 to 2.72). Out-of-hospital advanced airway (OR 0.73; 95% CI 0.67 to 0.80) was negatively associated with out-of-hospital cardiac arrest survival. CONCLUSION: In the PAROS cohort, bystander CPR, out-of-hospital defibrillation, and response time less than or equal to 8 minutes were positively associated with increased out-of-hospital cardiac arrest survival, whereas out-of-hospital advanced airway was associated with decreased out-of-hospital cardiac arrest survival. Developing EMS systems should focus on basic life support interventions in out-of-hospital cardiac arrest resuscitation.

Cost-effectiveness analysis of a 'Termination of Resuscitation' protocol for the management of out-of-hospital cardiac arrest.

BACKGROUND: Historically in Singapore, all out-of-hospital cardiac arrests (OHCA) were transported to hospital for pronouncement of death. A 'Termination of Resuscitation' (TOR) protocol, implemented from 2019 onwards, enables emergency responders to pronounce death at-scene in Singapore. This study aims to evaluate the cost-effectiveness of the TOR protocol for OHCA management. METHODS: Adopting a healthcare provider's perspective, a Markov model was developed to evaluate three competing options: No TOR, Observed TOR reflecting existing practice, and Full TOR if TOR is exercised fully. The model had a cycle duration of 30 days after the initial state of having a cardiac arrest, and was evaluated over a 10-year time horizon. Probabilistic sensitivity analysis was performed to account for uncertainties. The costs per quality adjusted life years (QALY) was calculated. RESULTS: A total of 3,695 OHCA cases eligible for the TOR protocol were analysed; mean age of 73.0 ± 15.5 years. For every 10,000 hypothetical patients, Observed TOR and Full TOR had more deaths by approximately 19 and 31 patients, respectively, compared to No TOR. Full TOR had the least costs and QALYs at $19,633,369 (95% Uncertainty Interval (UI) 19,469,973 to 19,796,764) and 0 QALYs. If TOR is exercised for every eligible case, it could expect to save approximately $400,440 per QALY loss compared to No TOR, and $821,151 per QALY loss compared to Observed TOR. CONCLUSION: The application of the TOR protocol for the management of OHCA was found to be cost-effective within acceptable willingness-to-pay thresholds, providing some justification for sustainable adoption.

Does witness type affect the chance of receiving bystander CPR in out-of-hospital cardiac arrest?

OBJECTIVES: The relationship between the bystander witness type and receipt of bystander CPR (BCPR) is not well understood. Herein we compared BCPR administration between family and non-family witnessed out-of-hospital cardiac arrest (OHCA). BACKGROUND: In many communities, interventions in the past decade have contributed to an increased receipt of BCPR, for example in Singapore from 15% to 60%. However, BCPR rates have plateaued despite sustained and ongoing community-based interventions, which may be related to gaps in education or training for various witness types. The purpose of this study was to investigate the association between witness type and BCPR administration. METHODS: Singapore data from 2010-2020 was extracted from the Pan-Asian Resuscitation Outcomes Study (PAROS) network registry (n = 25,024). All adult, layperson witnessed, non-traumatic OHCAs were included in this study. RESULTS: Of 10,016 eligible OHCA cases, 6,895 were family witnessed and 3,121 were non-family witnessed. After adjustment for potential confounders, BCPR administration was less likely for non-family witnessed OHCA (OR 0.83, 95% CI 0.75, 0.93). After location stratification, non-family witnessed OHCAs were less likely to receive BCPR in residential settings (OR 0.75, 95% CI 0.66, 0.85). In non-residential settings, there was no statistically significant association between witness type and BCPR administration (OR 1.11, 95% CI 0.88, 1.39). Details regarding witness type and bystander CPR were limited. CONCLUSION: This study found differences in BCPR administration between family and non-family witnessed OHCA cases. Elucidation of witness characteristics may be useful to determine populations that would benefit most from CPR education and training.

The association between mode of transport and out-of-hospital cardiac arrest outcomes in Singapore.

OBJECTIVE: We aimed to examine the survival outcomes of out-of-hospital cardiac arrest (OHCA) patients, stratified by the transportation modes to the Emergency Department (ED). METHODS: This was a retrospective analysis of Singapore's Pan-Asian Resuscitation Outcomes Study registry from Apr 2010-Dec 2017. The primary outcome was survival to discharge or 30 days post-arrest. Secondary outcomes were the return of spontaneous circulation (ROSC) rate and neurological outcomes. A subgroup analysis was performed for OHCA cases who collapsed enroute. RESULTS: A total of 15,376 cases were analysed. 15,129 (98.4%) were conveyed by Emergency Medical Services (EMS), 111 (0.72%) by private ambulance, 106 (0.69%) by own transport and 30 (0.2%) by public transport. 80% of patients brought by public transport arrested enroute, compared to 48.1% by own transport, 25.2% by private ambulance and 2.5% in the EMS group. 33/120 (27.5%) of paediatric OHCA cases were brought in by non-EMS transport to paediatric hospitals. The EMS group had the lowest survival rate at 4.5%, compared to 13.3% for public transport, 11.3% for own transport and 14.4% for private ambulance. ROSC rate was statistically significant but not for neurological outcomes. For the subgroup analysis, there was no statistical difference for primary and secondary outcomes across the groups. CONCLUSION: In Singapore, most OHCA patients are conveyed by EMS to the hospital, but some OHCA patients still arrive via alternative transport without prehospital interventions like bystander CPR. More can be done to educate the public to recognise an impending cardiac arrest and to activate EMS early for such cases.

Recognition and treatment of out-of-hospital cardiac arrests by non-emergency ambulance services in Singapore.

INTRODUCTION: Prompt recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) and defibrillation is necessary for good outcomes from out-of-hospital cardiac arrest (OHCA). This study aims to describe the recognition and treatment of OHCA in patients conveyed by non-emergency ambulance services (EAS) in Singapore. MATERIALS AND METHODS: This is a multi-centre, retrospective chart review, of cases presenting to public emergency departments (EDs), conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. The study was from October 2002 to August 2009. The following variables were examined: ability to recognise cardiac arrest, whether CPR was carried out by the ambulance crew and whether an automated external defibrillator (AED) was applied. RESULTS: Eighty-six patients were conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. Mean age was 63 years (SD 21.8), 70.9% were males. A total of 53.5% of arrests occurred in the ambulance while 70.9% were found to be asystolic upon ED arrival. Seven patients had a known terminal illness. Survival to discharge was 3.5%. Cardiac arrest went unrecognised by the ambulance crew in 38 patients (44.2%). CPR was performed in 35 patients (40.7%) of the 86 patients and AED was applied in only 10 patients (11.6%). CONCLUSION: We found inadequate recognition and delayed initiation of treatment for OHCA. Possible reasons include a lack of training in patient monitoring and detection of cardiac arrest, lack of CPR training, lack of confidence in performing CPR, lack of AEDs on ambulances and lack of training in their use.