Appropriate Duration of Resuscitation After Cardiac Arrest

Study Questions:

What is the appropriate duration of resuscitation in out-of-hospital cardiac arrest (OHCA)?


The authors analyzed data from a single-blind, multicenter, cluster-randomized clinical trial (ROC-PRIMED) of adult patients with Emergency Medical Services–treated OHCA. They assessed the association of duration of resuscitation in minutes (defined as onset of professional resuscitation to return of spontaneous circulation [ROSC] or termination of resuscitation) with survival to hospital discharge with favorable outcome (modified Rankin scale [mRS] 0-3). Subjects were additionally classified as survival with unfavorable outcome (mRS 4-5), ROSC without survival (mRS 6), or without ROSC. Adjusted logistic regression models were developed to test the association between resuscitation duration and survival with favorable outcome.


The study cohort included 11,368 subjects with a median age of 69 years; the majority were men (62.6%). Of these, 4,023 (35.4%) achieved ROSC, 1,232 (10.8%) survived to hospital discharge, and 905 (8.0%) had mRS 0-3 at discharge. Median professional cardiopulmonary resuscitation (CPR) duration was 20 minutes, and was shorter in those with ROSC (13.5 minutes) compared with those without ROSC (23.4 minutes). The longest observed duration of CPR was 202 minutes in any subject, and 47 minutes in subjects with eventual mRS 0-3. Distribution of CPR duration differed by outcome (p < 0.00001). For CPR duration up to 37.0 minutes (95% confidence interval, 34.9-40.9 minutes), 99% with eventual mRS 0-3 at discharge achieved ROSC. Probability of mRS 0-3 at discharge declined over elapsed resuscitation duration, but subjects with initial shockable cardiac rhythm, witnessed cardiac arrest, and bystander CPR were more likely to survive with a favorable outcome after prolonged efforts (30-40 minutes).


Shorter resuscitation duration is associated with the likelihood of a favorable outcome at hospital discharge, but some subjects with favorable case features were more likely to survive prolonged resuscitation up to 47 minutes.


The majority of patients with good neurological recovery after OHCA need CPR for ≤20 minutes, although there were a small number of patients who survived after prolonged cardiac arrest. An arbitrary cutoff for CPR duration (especially if short) might result in death of some patients who would otherwise survive with good neurological recovery.

Clinical Topics: Arrhythmias and Clinical EP, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Arrhythmias, Cardiac, Cardiopulmonary Resuscitation, Emergency Medical Services, Heart Arrest, Out-of-Hospital Cardiac Arrest, Pulmonary Circulation, Outcome Assessment (Health Care), Patient Discharge, Primary Prevention, Resuscitation, Survival

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