What is the Optimal Chest Compression Depth During Out-of-Hospital Cardiac Arrest Resuscitation of Adult Patients?
Background—The 2010 AHA guidelines suggested an increase in CPR compression depth with a target greater than 50 mm and no upper limit. This target is based upon limited evidence and we sought to determine the optimal compression depth range.
Methods and Results—We studied emergency medical services treated out-of-hospital cardiac arrest (OHCA) patients from the Resuscitation Outcomes Consortium ROC PRIMED clinical trial and Epistry - Cardiac Arrest database. We calculated adjusted odds ratios for survival to hospital discharge, one-day survival, and any return of circulation (ROSC). We included 9,136 adult patients from 9 U.S. and Canadian cities that had mean age 67.5 years; mean compression depth 41.9 mm; and had ROSC 31.3%, one-day survival 22.8%, and survival to hospital discharge 7.3%. For survival to discharge, the adjusted odds ratios were 1.04 (95% CI 1.00, 1.08) for each 5 mm increment in compression depth, 1.45 (1.20, 1.76) for cases within 2005 depth range (>38 mm), and 1.05 (1.03, 1.08) for percent of minutes in depth range (10% change). Covariate-adjusted spline curves revealed that the maximum survival is at a depth of 45.6 mm (15 mm interval with highest survival between 40.3 to 55.3) with no differences between males and females.
Conclusions—This large study of OHCA patients demonstrated that increased CPR compression depth is strongly associated with better survival. Our adjusted analyses, however, found maximum survival was in the depth interval of 40.3 to 55.3 mm (peak 45.6 mm), suggesting that the 2010 AHA CPR guideline target may be too high.
Clinical Trial Registration Information—clinicaltrials.gov. Identifier: NCT00394706.
- Received January 15, 2014.
- Revision received September 3, 2014.
- Accepted September 11, 2014.