Objectives: Although mechanical cardiopulmonary resuscitation (mCPR) for out-of-hospital cardiac arrest (OHCA) patients attending the emergency department (ED) has become more widespread, little is known about the real-world use of mCPR in the ED and the association with the outcomes among adult OHCA. The aim of this study is to determine the association between the mCPR for adult nontraumatic OHCA patients attending the ED and the clinical outcomes.
Methods: Using data from a prospective, multicenter, observational study, adult OHCA patients attending the ED with sustained circulatory arrest upon hospital arrival were identified. The primary outcome was survival to hospital discharge. Multivariate analyses adjusted for potential confounders and within-institution clustering effects using a generalized estimation equation were employed to analyze the association between the mCPR and the outcomes.
Results: Between January 2012 and March 2013, 6,537 patients who experienced OHCA were eligible for inclusion in this study; this included 5,619 (86.0%) patients in the manual CPR group and 918 (14.0 %) patients in the mCPR group. In the observed dataset, 2.6% (152/5,767) of the patients survived to hospital discharge, 28.3% (1,611/5,699) showed a return of spontaneous circulation (ROSC) in the ED, 20.5% (1,041/5,077) were successfully admitted to the hospital, and 1.2% (71/5,764) showed a favorable neurological outcome at 1 month. In the imputed dataset for missing data, a multivariate analysis revealed that mCPR was associated with a decreased likelihood of survival to hospital discharge (adjusted OR, 0.42; 95% CI, 0.22-0.80; P=0.008). Also, mCPR was associated with a decreased likelihood of ROSC, hospital admission, and a favorable neurological outcome. In the sub-group analyses, mCPR was significantly associated with a decreased likelihood of survival to hospital discharge in the following sub-groups: male, cardiac etiology, day-time, witnessed status, receiving bystander CPR, and an initial shockable rhythm.
Conclusions: The mCPR in the ED was associated with a decreased likelihood of a good clinical outcome after adult nontraumatic OHCA. Further studies should be performed to clarify circumstances in which mCPR may benefit these patients.