title: CPR with chest compression alone or with rescue breathing.
abstract: BACKGROUND
  The role of rescue breathing in cardiopulmonary resuscitation (CPR) performed by a layperson is uncertain. We hypothesized that the dispatcher instructions to bystanders to provide chest compression alone would result in improved survival as compared with instructions to provide chest compression plus rescue breathing.
  
  
  METHODS
  We conducted a multicenter, randomized trial of dispatcher instructions to bystanders for performing CPR. The patients were persons 18 years of age or older with out-of-hospital cardiac arrest for whom dispatchers initiated CPR instruction to bystanders. Patients were randomly assigned to receive chest compression alone or chest compression plus rescue breathing. The primary outcome was survival to hospital discharge. Secondary outcomes included a favorable neurologic outcome at discharge.
  
  
  RESULTS
  Of the 1941 patients who met the inclusion criteria, 981 were randomly assigned to receive chest compression alone and 960 to receive chest compression plus rescue breathing. We observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge (12.5% with chest compression alone and 11.0% with chest compression plus rescue breathing, P=0.31) or in the proportion who survived with a favorable neurologic outcome in the two sites that assessed this secondary outcome (14.4% and 11.5%, respectively; P=0.13). Prespecified subgroup analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone as compared with chest compression plus rescue breathing for patients with a cardiac cause of arrest (15.5% vs. 12.3%, P=0.09) and for those with shockable rhythms (31.9% vs. 25.7%, P=0.09).
  
  
  CONCLUSIONS
  Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups. The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing. (Funded in part by the Laerdal Foundation for Acute Medicine and the Medic One Foundation; ClinicalTrials.gov number, NCT00219687.)
authors.affiliation: Emergency Medical Services Division of Public Health for Seattle and King County, Seattle, Washington, USA. rea123@u.washington.edu
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Rea
authors.forename: Carol
authors.initials: C
authors.lastname: Fahrenbruch
authors.forename: Linda
authors.initials: L
authors.lastname: Culley
authors.forename: Rachael T
authors.initials: RT
authors.lastname: Donohoe
authors.forename: Cindy
authors.initials: C
authors.lastname: Hambly
authors.forename: Jennifer
authors.initials: J
authors.lastname: Innes
authors.forename: Megan
authors.initials: M
authors.lastname: Bloomingdale
authors.forename: Cleo
authors.initials: C
authors.lastname: Subido
authors.forename: Steven
authors.initials: S
authors.lastname: Romines
authors.forename: Mickey S
authors.initials: MS
authors.lastname: Eisenberg
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D016009:Chi-Square Distribution; D004631:Emergency Medical Service Communication Systems; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial; D018709:Statistics, Nonparametric; D015996:Survival Rate; D014838:Volunteers