Mechanical versus manual chest compressions in out-of-hospital cardiac arrest: a meta-analysis

The objective of this study was to conduct a meta-analysis of literature examining rates of return of spontaneous circulation from load-distributing band and piston-driven chest compression devices as compared with manual cardiopulmonary resuscitation.

Searches were conducted in MEDLINE, the ClinicalTrials.gov registry, and bibliographies on manufacturer websites for studies written in English.

Selection criteria for the meta-analysis required that studies must be human controlled (randomized, historical, or case-control) investigations with confirmed out-of-hospital cases.

A total of 12 studies (load-distributing band cardiopulmonary resuscitation versus manual cardiopulmonary resuscitation = 8, piston-driven cardiopulmonary resuscitation versus manual cardiopulmonary resuscitation = 4), comprising a total of 6,538 subjects with 1,824 return of spontaneous circulation events, met the selection criteria.

Random effects models were used to assess the relative effect of treatments on return of spontaneous circulation. Compared with manual cardiopulmonary resuscitation, load-distributing band cardiopulmonary resuscitation had significantly greater odds of return of spontaneous circulation (odds ratio, 1.62 [95% CI, 1.36, 1.92], p < 0.001). The treatment effect for piston-driven cardiopulmonary resuscitation was similar to manual cardiopulmonary resuscitation (odds ratio, 1.25 [95% CI, 0.92, 1.68];p = 0.151). The corresponding difference in percentages of return of spontaneous circulation rates from cardiopulmonary resuscitation was 8.3% for load-distributing band cardiopulmonary resuscitation and 5.2% for piston-driven cardiopulmonary resuscitation. Compared with manual cardiopulmonary resuscitation, combining both mechanical cardiopulmonary resuscitation devices produced a significant treatment effect in favor of higher odds of return of spontaneous circulation with mechanical cardiopulmonary resuscitation devices (odds ratio, 1.53 [95% CI, 1.32, 1.78], p < 0.001).

The ability to achieve return of spontaneous circulation with mechanical chest compression devices is significantly improved when compared with manual chest compressions. In the case of load-distributing band cardiopulmonary resuscitation, it was superior to manual cardiopulmonary resuscitation as the odds of return of spontaneous circulation were over 1.6 times greater. The robustness of these findings should be tested in large randomized clinical trials.