title: The effect on quality of chest compressions and exhaustion of a compression--ventilation ratio of 30:2 versus 15:2 during cardiopulmonary resuscitation--a randomised trial.
abstract: BACKGROUND
  Recent cardio pulmonary resuscitation (CPR) guidelines changed the compression:ventilation ratio in 30:2.
  
  
  OBJECTIVE
  To compare the quality of chest compressions and exhaustion using the ratio 30:2 versus 15:2.
  
  
  METHODS
  A prospective, randomised crossover design was used. Subjects were recruited from the H.-Hart hospital personnel and the University College Katho for nurses and bio-engineering. Each participant performed 5min of CPR using either the ratio 30:2 or 15:2, then after a 15min rest switched to the other ratio. The data were collected using a questionnaire and an adult resuscitation manikin. The outcomes included exhaustion as measured by a visual analogue scale (VAS) score, depth of chest compressions, rates of chest compressions, total number of chest compressions, number of correct chest compressions and incomplete release. Data were compared using the Wilcoxon Signed Ranks Test. The results are presented as medians and interquartile ranges (IQR).
  
  
  RESULTS
  One hundred and thirty subjects completed the study. The exhaustion-score using the VAS was 5.9 (IQR 2.25) for the ratio 30:2 and 4.5 (IQR 2.88) for the ratio 15:2 (P<0.001). The compression depth was 40.5mm (IQR 15.75) for 30:2 and 41mm (IQR 15.5) for 15:2 (P=0.5). The compression rate was 118beats/min (IQR 29) for 30:2 and 115beats/min (IQR 32) for 15:2 (P=0.02). The total number of compressions/5min was 347 (IQR 79) for 30:2 and 244compressions/5min (IQR 72.5) for 15:2 (P<0.001). The number of correct compression/5min was 61.5 (IQR 211.75) for 30:2 and 55.5 (IQR 142.75) for 15:2 (P=0.001). The relative risk (RR) of incomplete release in 30:2 versus 15:2 was 1.087 (95% CI=0.633-1.867).
  
  
  CONCLUSIONS
  Although the 30:2 ratio is rated to be more exhausting, the 30:2 technique delivers more chest compressions and the quality of chest compressions remains unchanged.
authors.affiliation: Education and Research, Paramedical Assistance, Roeselare, Belgium. koen@paramedicalassistance.be
authors.forename: Koen
authors.initials: K
authors.lastname: Deschilder
authors.forename: Rien
authors.initials: R
authors.lastname: De Vos
authors.forename: Willem
authors.initials: W
authors.lastname: Stockman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D018592:Cross-Over Studies; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D011446:Prospective Studies; D011787:Quality of Health Care; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires