Objective: To identify distinct criteria for appropriate on-scene termination of resuscitation efforts for out-of-hospital cardiac arrest when on-scene interventions fail to restore spontaneous circulation.
Design: For 18 months, all out-of-hospital cardiac arrests were evaluated prospectively for survival to hospital discharge and for all established survival predictors including age, gender, presenting cardiac rhythm, whether it was a witnessed event, performance of basic cardiopulmonary resuscitation by bystanders, and interval to paramedic arrival and return of spontaneous circulation (ROSC).
Setting: A large municipality with a single, centralized emergency medical services program.
Patients: All normothermic adults treated for out-of-hospital, unmonitored, primary cardiac arrest.
Interventions: Standard advanced cardiac life support provided at the scene by paramedics.
Main outcome measures: The number and circumstances of patients achieving survival to hospital discharge following failure to achieve on-scene ROSC.
Results: Of 1461 consecutive primary cardiac arrests, 139 were monitored (paramedic witnessed), including 59 that occurred en route to the hospital. Of the 1322 unmonitored patients, 370 achieved ROSC at the scene. Only six (0.6%) of the 952 who did not achieve ROSC at the scene survived, and all six were readily identifiable as having persistent ventricular fibrillation. Excluding those patients with persistent ventricular fibrillation, all survivors achieved ROSC within 25 minutes after paramedic arrival.
Conclusions: Excluding patients with persistent ventricular fibrillation, resuscitative efforts can be terminated at the scene when normothermic adults with unmonitored, out-of-hospital, primary cardiac arrest do not regain spontaneous circulation within 25 minutes following standard advanced cardiac life support. These criteria should now be validated in several large centers with high survival rates.