Cardiac Arrest Resuscitation Evaluation in Los Angeles: CARE-LA.

STUDY
OBJECTIVE: We determine survival for out-of-hospital cardiac arrests in Los Angeles using the Utstein method and compare these data with that reported for other urban and suburban areas.
METHODS: This was a prospective observational cohort study of adult patients in Los Angeles presenting with nontraumatic, out-of-hospital cardiac arrest and with attempted out-of-hospital resuscitative efforts between July 1, 2000, and July 1, 2001. Entry criteria, time intervals, and nodal events conformed to Utstein template recommendations. The single target endpoint was neurologically intact survival at hospital discharge.
RESULTS: Of 2,021 consecutive cardiac arrest patients on whom resuscitation was attempted, 1,700 (84%) met entry criteria as a primary cardiac event. Overall, neurologically intact survival was 1.4% (99% confidence interval [CI] 0.8% to 2.4%) Three patients were lost to follow-up. Survival from bystander-witnessed ventricular fibrillation was 6.1% (99% CI 3.3% to 11.0%). Absolute survival differences from witnessed ventricular fibrillation was higher but not statistically different than that from Chicago (-3%; 99% CI -8% to 2%) and New York City (-2%; 99% CI -6% to 3%). The rate of bystander cardiopulmonary resuscitation (CPR) for our population was 28%, for which the overall survival rate was 2.1%. The survival rate for patients with witnessed arrests and bystander CPR was 3.2%. Among patients with no bystander CPR, the survival rate was 1.0%.
CONCLUSION: Survival from out-of-hospital cardiac arrest in Los Angeles was low but similar to that reported for New York and Chicago. This low survival rate may be due to population density, low bystander CPR rates, and traffic congestion delaying emergency response.