In CPR, the optimal chest compression rate is 107 compressions per minute and the optimal chest compression depth is 4.7 cm, according to a study published in JAMA Cardiology.
The researchers analyzed 3,643 patients (mean age, 68 years; 64% men) who had out-of-hospital cardiac arrest between June 2007 and November 2009 and whose chest compression rate and chest compression depth were recorded as part of ROC PRIMED, an NIH trial of a CPR adjunct, an impedance threshold device.
The primary outcome was functionally favorable survival, defined as a modified Rankin Scale score of 3 or less.
Sue Duval, PhD, associate professor of medicine/cardiology at University of Minnesota Twin Cities in Minneapolis, and colleagues identified 107 compressions per minute as the optimal chest compression rate and 4.7 cm as the optimal chest compression depth. They found that if CPR was performed within 20% of both those parameters, functionally favorable survival was 6% vs. 4.3% if it was not (OR = 1.44; 95% CI, 1.07-1.94).
The optimal combination was consistent regardless of sex, age, presenting cardiac rhythm or CPR adjunct use, according to the researchers.
Use of the optimal combination yielded better results in patients assigned the CPR adjunct than in patients assigned standard CPR (OR = 1.9; 95% CI, 1.06-3.38), and the effectiveness of the adjunct depended on use of the optimal combination, Duval and colleagues wrote.
“Although the combination may not be the eventual definitive answer regarding optimal rate and depth, it is an important step in the process of finding the best practice and determining whether the combination varies according to various factors,” the researchers wrote.
“Given that the 20% window around the identified optimal combination largely overlaps with current international recommendations for rate and depth, emergency medical services systems that opt to implement the proposed combination now, prior to validation, are likely acting reasonably,” David C. Cone, MD, associate professor of surgery (emergency medicine) and public health at Yale School of Medicine, wrote in a related editorial. “While the findings of Duval et al are unlikely to lead to a change in international CPR guidelines on their own, they do support the simplest CPR mantra: Push hard, push fast and do not stop.” – by Erik Swain
Disclosures: Cone and Duval report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.