Objective: To determine survival after out-of-hospital cardiac arrest (CA) in Copenhagen, according to the Utstein recommendations, and compare this with other emergency medical services systems.
Design: Register-based cohort study.
Setting: Copenhagen, population 465000, area 90 km(2).
Patients: Consecutive group of patients with out-of-hospital CA occurring between January 1 1991 and December 31 1993, followed up via the hospital database systems.
Materials: Two specially equipped advanced life support (ALS) units, staffed with an anaesthesiologist and a specially trained fireman, operating to support basic life support units.
Results: Of 2225 patients who were unconscious without a pulse or breathing, 1461 were declared dead by the anaesthesiologist. Advanced cardiac life support was initiated in 764, 61 of which were of non-cardiac aetiology. The presumed aetiology was cardiac in 703: in 235 the event was unwitnessed, in 464 witnessed and in four the information was missing. Of 464 witnessed CA the initial rhythm was asystole in 72 cases, in 302 ventricular fibrillation (VF) or ventricular tachycardia (VT), and in 90 were in other rhythms. In these subgroups discharged rates were 5 (7%), 62 (21%) and 1 (1%), and 1-year survival rates were 4 (6%), 49 (16%) and 1 (1%), respectively. The median ALS call-response interval was 6 min.
Conclusions: Survival after CA is more likely if the collapse was witnessed and in patients with VF/VT of cardiac aetiology.