This article is more than 5 years old. Information may no longer be current.

Continuous chest compressions during CPR do not improve survival rates

Data from a cluster-randomized trial demonstrated that continuous chest compressions during CPR did not affect survival or neurological function compared with interrupted chest compressions.

Graham Nichol, MD, MPH, the director of the University of Washington Medical Center/Harborview Medical Center for Prehospital Emergency Care in Seattle, and colleagues wrote in The New England Journal of Medicine that ventilation given as rescue breathing interrupts chest compressions during out-of-hospital cardiac arrest.

"These interruptions reduce blood flow and potentially reduce the effectiveness of CPR," they wrote. "One strategy to reduce the interruption of compressions is to provide asynchronous positive-pressure ventilation while not pausing for ventilations."

The study was conducted by the Resuscitation Outcomes Consortium (ROC), and included eight ROC sites and 114 emergency medical service (EMS) agencies. Agencies were randomly assigned to perform interrupted chest compressions or continuous chest compression during all out-of-hospital cardiac arrests. All agencies also crossed over to the other strategy twice each year.

Nichol and colleagues defined the strategies as follows: patients who received continuous chest compressions received compressions at a rate of 100 per minute along with asynchronous positive-pressure ventilations at a rate of 10 per minute and patients who received interrupted chest compressions received compressions interrupted for ventilations at a rate of 30 compressions to two ventilations.

The researchers included data for 23,711 patients who suffered from nontrauma-related out-of-hospital cardiac arrest: 12,653 patients received continuous chest compressions and 11,058 patients received interrupted chest compressions. Survival data were available for 12,613 patients who received continuous chest compressions and 11,035 patients who received interrupted chest compressions.

Results demonstrated that 1,129 patients (9%) who received continuous chest compressions and 1,072 patients (9.7%) who received interrupted chest compressions survived to hospital discharge (difference = –0.7 percentage points; 95% CI, –1.5 to 0.1; P = .07). In patients with neurological data, 883 patients (7%) who received continuous chest compressions and 844 patients (7.7%) who received interrupted chest compressions survived with favorable neurologic function at hospital discharge (difference = –0.6 percentage points; 95% CI, –1.4 to 0.1; P = .09).

Patients who received continuous chest compressions were less likely to be transported to the hospital (difference = –2.0 percentage points; 95% CI, –3.6 to 0.5; P = .01) or be admitted to the hospital (difference = –1.3 percentage points; 95% CI, –2.4 to –0.2; P = .03). Additionally, hospital-free survival was shorter for patients who received continuous chest compressions (mean difference = –0.2 days; 95% CI, –0.3 to –0.1; P = .004).

"A strategy of continuous manual chest compressions with positive-pressure ventilation was not associated with a significantly higher rate of survival to discharge or favorable neurologic function than a strategy of manual chest compressions with interruptions for ventilation performed by EMS providers,” Nichol and colleagues wrote. “The group assigned to receive continuous chest compressions had significantly lower rates of transport to the hospital and admission to the hospital, as well as shorter hospital-free survival, than the group assigned to receive interrupted chest compressions. In the per-protocol analyses, patients who received continuous chest compressions had significantly lower survival rates than those who received compressions with interruptions." – by Chelsea Frajerman Pardes

Disclosures: Nichol reports grant support from the National Heart Lung Blood Institute and other support from the Medic One Foundation during the conduct of the study; grant support from the Food and Drug Administration, ZOLL Medical, Cardiac Science Corp., HeartSine Technologies, Philips Healthcare,Physio-Control, Neuroprotexeon, and Sotera Wireless, and nonfinancial support from Abiomed outside the submitted work. Please see the full study for a list of all other authors' relevant financial disclosures.