Title: “Trial of Continuous or Interrupted Chest Compressions during CPR”

Article Citation: Nichol G, Leroux B, Wang H, Callaway CW, et al; ROC Investigators. Trial of Continuous or Interrupted Chest Compressions during CPR. N Engl J Med. 2015 Dec 3;373(23):2203-14. PMID: 26550795

What we already know about the topic: Animal models have demonstrated that interruptions in cardiac arrest result in decreased survival. There has not been any human studies confirming this to date.

Why this study is important:  This study is the first attempt to demonstrate that there is survival benefit from continued compressions in humans in cardiac arrest in the pre-hospital setting.

Brief overview of the study:  From 2011 to 2015 patients in cardiac arrest were randomly assigned to either an intervention group (continuous chest compressions at 100/min with 10 ventilations/minute = 12,653 patients) or to a control group (compressions interrupted for ventilations = 11,058 patients) in 114 EMS systems. Outcome measures included rate of survival to discharge, neurologic function at discharge (suing modified Rankin Scale), adverse events, and hospital-free survival days (ie number of days alive outside of hospital for 30 days).  The study found no statistical difference between either group’s rate of survival to discharge or neurologic function.  Of note the study demonstrates with statistical significance that the compressions-only group was less likely to be transported or admitted to the hospital, and this group also had shorter hospital-free survival.

Limitations: My primary issues with this study are: (1) These findings were performed by EMS and so can only be applied reliably to the pre-hospital setting. (2) The study did not account for in-hospital interventions (catheterizations, thrombolytics, etc) (3) The study excludes EMS-witnessed arrest, traumatic arrest, hypoxic arrest, exsanguination, and others.

Take home points: Outcomes for compressions-only CPR and interrupted CPR were very similar. This is the best data we have available to date describing these two approaches. While we cannot reliably apply these data to the hospital setting it does change how our patients will be managed prior to arrival.