Which method of resuscitation optimizes outcomes of out-of-hospital cardiac arrest: manual chest compression or the use of an automated chest compression device?

Current evidence is unable to support a recommendation for the use of either manual chest compression or an automated chest compression device for out-of-hospital cardiac arrest resuscitation. Overall survival with good neurologic function at hospital discharge occurs in fewer than 10% of individuals with the use of either cardiac pulmonary resuscitation (CPR) method. (LOE = 1b-)

Hallstrom A, Rea TD, Sayre MR, et al. Manual chest compression vs use of an automated chest compression device during resuscitation following out-of-hospital cardiac arrest. A randomized trial. JAMA 2006;295:2620-2628.  [PMID:16772625]

Randomized controlled trial (nonblinded)

Industry

Unconcealed

Population-based

These investigators randomized (allocation assignment not concealed) 1071 eligible adults, 18 years or older, with out-of-hospital cardiac arrest presumed to be of cardiac origin to CPR via standard manual chest compression or the use of an automated load-distributing band (LDB) chest compression device. Study outcomes included survival with spontaneous circulation at 4 hours, survival to hospital discharge, and neurologic function at discharge. Individuals assessing outcomes were not blinded to treatment group survival, but the major outcome of interest -- mortality -- is not subject to interpretation. Follow-up occurred for all eligible subjects until hospital discharge. Using intention-to-treat analysis, no significant difference occurred in the end point of survival to 4 hours between the manual and LDB CPR group. Survival to hospital discharge was nonsignificantly higher in the manual CPR group than in the LDB CPR group (9.9% vs 5.8%), but the safety monitoring board stopped the study prematurely. Neurologic outcome at hospital discharge was significantly better in the manual CPR group, with 7.5% vs 3.1% of patients achieving a cerebral performance category score of 1 or 2. In a very similar report in the same journal (JAMA 2006;295:2629-37) that used a before-after study design, resuscitation with a LDB device was associated with a slightly but significantly improved survival to hospital discharge. However, among patients surviving to hospital discharge, overall neurologic outcomes were similar between groups. In an accompanying editorial in the same journal, the author points out that the seemingly contradictory results are most likely the result of methodological differences and possible sources of biased results in both studies, including the differences in deployment time required for the LDP device, enrollment bias due to nonconcealed allocation assignment, and the potential for the Hawthorne effect (ie, improved performance during the study as a result of being closely observed) on the manual CPR.