Cardiac arrest and resuscitation epidemiology in Singapore (CARE I study)

To describe the epidemiology of out-of-hospital cardiac arrest (OHCA) in Singapore, the emergency medical services (EMS) response, and to identify possible areas for improvement.

This prospective observational study constitutes phase I of the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Included were all patients with nontraumatic OHCA conveyed by the national emergency ambulance service. Patient characteristics, cardiac arrest circumstances, EMS response, and outcomes were recorded according to the Utstein style.

From October 1, 2001, to April 30, 2002, 548 patients were enrolled into the study. Mean (standard deviation [SD]) age was 62.2 (17.9) years, with a male predominance (65.6%). A total of 59.8% of collapses occurred at home, 35.3% of arrests were not witnessed, and bystander cardiopulmonary resuscitation was present for 20.6%. Mean (SD) time from collapse to call received by EMS was 10.6 (13.1) minutes. Mean (SD) EMS response time was 10.2 (4.3) minutes. Mean (SD) time from call to defibrillation was 16.7 (7.2) minutes. Mean (SD) on-scene time was 9.9 (4.5) minutes. First presenting rhythm at the scene was asystole in 54.5%, pulseless electrical activity 22.9%, ventricular fibrillation 19.6%, and ventricular tachycardia 0.4%. Of all cardiac arrests, 351 had resuscitation attempted and were of cardiac origin. Among these patients, 17.9% had return of spontaneous circulation, 8.5% survived to hospital admission, and 2.0% survived to discharge.

CARE I establishes the baseline for the evaluation of incremental introduction of prehospital Advanced Cardiac Life Support interventions planned for future phases. Continuing efforts should be made to strengthen all chains of survival. This represents the most comprehensive OHCA study yet conducted in Singapore.