What are representative survival rates for out-of-hospital cardiac arrest? Insights from the New Haven (Conn) experience.

BACKGROUND

Survival rates from out-of-hospital cardiac arrests due to ventricular fibrillation or pulseless ventricular tachycardia vary greatly. The majority of published reports indicate a survival range from 11% to 33%, depending on the area of observation. Two recent series from major metropolitan centers describe markedly less favorable outcomes and have led to speculation that dense urbanization may contribute to worse outcomes.

METHODS

Examination of a consecutive series of out-of-hospital cardiac arrests in New Haven, Conn, a city of 127,000 people and 55 km2 with a two-tiered emergency response system. All cases of nontraumatic cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia occurring outside of a hospital between January 1988 and June 1989 were considered. That city's emergency medical system employs emergency medical technicians and paramedics. Standard resuscitation techniques were employed; high-dose epinephrine and interposed abdominal counterpulsations were not routine interventions. The main outcome measure was survival to hospital discharge.

RESULTS

Three (4.0%) of 75 patients survived cardiac arrest and were discharged alive from the hospital. Two (5.3%) of 38 witnessed arrests resulted in hospital discharges. Patient demographics were typical of those reported from other cities that have published outcomes data. Few patients (16%) received bystander-initiated cardiopulmonary resuscitation.

CONCLUSION

There is increasing evidence that previously recognized standards for resuscitation success may not be present in certain types of municipalities, including this northeastern city. A registry of outcomes from out-of-hospital cardiac arrests would help to clarify the true national experience.