title: Compression-only cardiopulmonary resuscitation vs standard cardiopulmonary resuscitation: an updated meta-analysis of observational studies.
abstract: OBJECTIVE
  To perform an updated meta-analysis of observational studies with unstratified cohort addressing whether compression-only cardiopulmonary resuscitation (CPR), compared with standard CPR, improves outcomes in adult patients with out-of-hospital cardiac arrest and a subgroup meta-analysis for the patients with cardiac etiology arrest.
  
  
  METHODS
  We searched the relevant literature from MEDLINE and EMBASE databases. The baseline information and outcome data (survival to hospital discharge, favorable neurologic outcome at hospital discharge, and return of spontaneous circulation on hospital arrival) were extracted both in an out-of-hospital cardiac arrest and cardiac origin arrest subgroup. Meta-analyses were performed by using Review Manager 5.0.
  
  
  RESULTS
  Eight studies involving 92,033 patients were eligible. Overall meta-analysis showed that standard CPR was associated with statistically improved survival to hospital discharge (risk ratio [RR], 0.95 [95% confidence interval, 0.91-0.99]) and return of spontaneous circulation on hospital arrival (RR, 0.95 [95% confidence interval, 0.92-0.99]) compared with compression-only CPR, but there is no significant difference in favorable neurologic outcome at hospital discharge between 2 CPR methods (RR, 0.97 [95% confidence interval, 0.91-1.04]). In the subgroup of patients with a cardiac cause of arrest, the pooled meta-analysis found compression-only CPR resulted in the similar survival to hospital discharge as standard CPR (RR, 0.99 [95% confidence interval, 0.94-1.05]).
  
  
  CONCLUSIONS
  This meta-analysis found that compression-only CPR resulted in the similar survival rate as the standard CPR in the cardiac etiology subgroup. It is unclear for the patients with noncardiac cause of arrest and with long periods of untreated arrest.
authors.affiliation: Department of Emergency Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai, China; Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Yao
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Mingdi
authors.initials: M
authors.lastname: Chen
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yuanshan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Xiaozhu
authors.initials: X
authors.lastname: Wei
authors.affiliation: Institute of Cardiopulmonary Cerebral Resuscitation, Sun Yat-sen University, Guangzhou, China; Department of Emergency Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China. Electronic address: wang2it@163.com.
authors.forename: Zitong
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000328:Adult; D016887:Cardiopulmonary Resuscitation; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy; D006336:Heart Massage; D006801:Humans; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy; D016896:Treatment Outcome