title: Effect of one-rescuer compression/ventilation ratios on cardiopulmonary resuscitation in infant, pediatric, and adult manikins.
abstract: OBJECTIVE
  Optimal chest compression to ventilation ratio (C:V) for one-rescuer cardiopulmonary resuscitation (CPR) is not known, with current American Heart Association recommendations 3:1 for newborns, 5:1 for children, and 15:2 for adults. C:V ratios influence effectiveness of CPR, but memorizing different ratios is educationally cumbersome. We hypothesized that a 10:2 ratio might provide adequate universal application for all age arrest victims.
  
  
  METHODS
  Clinical study.
  
  
  METHODS
  Tertiary care children's hospital.
  
  
  METHODS
  Thirty-five health care providers.
  
  
  METHODS
  Thirty-five health care providers performed 5-min epochs of one-rescuer CPR at C:V ratios of 3:1, 5:1, 10:2, and 15:2 in random order on infant, pediatric, and adult manikins. Compressions were paced at 100/min by metronome. The number of effective compressions and ventilations delivered per minute was recorded by a trained basic life support instructor. Subjective assessments of fatigue (self-report) and exertion (change in rescuer pulse rate compared with baseline) were assessed. Analysis was by repeated measures analysis of variance and paired Student's t-test.
  
  
  RESULTS
  Effective infant compressions per minute did not differ by C:V ratio, but ventilations per minute were greater at 3:1 vs. 5:1, 10:2, and 15:2 (p < .05). Effective pediatric compressions per minute were less at 3:1 vs. 5:1, 10:2, and 15:2 (p < .05) and not different between 5:1, 10:2, and 15:2 ratios. Effective pediatric ventilations per minute were greater at 3:1 than all other ratios and both 5:1 and 10:2 were >15:2 (p < .05). Effective adult compressions per minute were progressively greater with 3:1 vs. 5:1 vs. 10:2 vs. 15:2 (p < .05). Self-efficacy was assessed, and rescuers always subjectively rated 10:2 and 15:2 ratios as easier than 5:1 or 3:1 ratios for all manikins. Rescuer pulse change (exertion) was greater after pediatric and adult vs. infant CPR (p < .05), with no significant difference by C:V ratio.
  
  
  CONCLUSIONS
  C:V ratio and manikin size have a significant influence on the number of effective compressions and ventilations delivered during ideal, metronome-paced, one-rescuer CPR. Low ratios of 3:1, 5:1, and 10:2 favor ventilation, and high ratios of 15:2 favor compression, especially in adult manikins. Rescuers subjectively preferred C:V ratios of 10:2 and 15:2 over 3:1 or 5:1. Infant CPR caused less exertion and subjective fatigue than pediatric or adult CPR technique, without significant difference by C:V ratio. We speculate that a universal 10:2 C:V ratio for one-rescuer layperson CPR is physiologically reasonable but warrants further study with particular attention to educational value and technique retention.
authors.affiliation: Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Shoba Krishnan
authors.initials: SK
authors.lastname: Srikantan
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Tim
authors.initials: T
authors.lastname: Cox
authors.forename: Lisa
authors.initials: L
authors.lastname: Tice
authors.forename: Vinay M
authors.initials: VM
authors.lastname: Nadkarni
mesh_terms: D000328:Adult; D000367:Age Factors; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D002648:Child; D002983:Clinical Competence; D005221:Fatigue; D006801:Humans; D007231:Infant, Newborn; D008348:Manikins; D005082:Physical Exertion; D018635:Rescue Work; D015656:Respiratory Mechanics