Bystander cardiopulmonary resuscitation in prehospital cardiac arrest patients in Singapore.

INTRODUCTION: The chain of survival emphasizes the importance of the four links associated with survival after cardiac arrest (CA). The involvement of laypersons has been increasing over the years. They have been contributing toward "early access," "early cardiopulmonary resuscitation" (CPR), and, of late, "early defibrillation," with the advent of automated external defibrillators (AEDs). Bystander CPR rates are difficult to assess due to the lack of formal documentation.

OBJECTIVE: To assess the bystander CPR rate for CA patients brought to the emergency department (ED) of an urban, tertiary teaching hospital in the central part of Singapore, over a period of 12 months.

METHODS: This was a retrospective cohort study carried out from May 1, 1999, to April 30, 2000. "Bystander CPR" refers to an attempt to perform basic CPR by someone who is not part of an organized emergency response system. In general, this refers to the person who witnesses the arrest.

RESULTS: There were 155 adult patients with CA who satisfied the inclusion criteria over the 12-month period. The median age was 62.1 +/- 6.4 years, and the majority of patients were brought in by ambulances (126, or 81.3%). There were 142 (91.6%) non-trauma and 13 (8.4%) trauma CAs. Most patients had the CA at home (96, or 61.9%), and the most common initial rhythm at presentation upon the arrival of the paramedics was ventricular fibrillation (VF) (50 patients, or 32.2%). The bystander CPR rate was 20.0% (i.e., 31 of the 155 patients). A total of 32 (20.6%) patients had return of spontaneous circulation (ROSC, defined as the return of a palpable pulse) and 31 (96.9%, or 31/32) of them were those who had some form of bystander CPR performed. Of these 31 who had bystander CPR, four (12.9%) were subsequently admitted to the intensive care unit (ICU), while among those who did not have bystander CPR, all had death pronounced in the ED. Of the four patients admitted to the ICU, three (3 of 4, or 75.0%; or 3 of 155 CA patients, or 1.9%) were subsequently discharged alive from the hospital.

CONCLUSION: The bystander CPR rate for prehospital CA was 20.0%. About 12.9% (4 patients) of those who had bystander CPR were admitted to the ICU, compared with none from the group that did not receive any form of bystander CPR. Three patients (1.9% of all prehospital CAs) were discharged alive from the hospital.