title: Bystander fatigue and CPR quality by older bystanders: a randomized crossover trial comparing continuous chest compressions and 30:2 compressions to ventilations.
abstract: OBJECTIVE
  This study sought to measure bystander fatigue and cardiopulmonary resuscitation (CPR) quality after five minutes of CPR using the continuous chest compression (CCC) versus the 30:2 chest compression to ventilation method in older lay persons, a population most likely to perform CPR on cardiac arrest victims.
  
  
  METHODS
  This randomized crossover trial took place at three tertiary care hospitals and a seniors' center. Participants were aged ≥55 years without significant physical limitations (frailty score ≤3/7). They completed two 5-minute CPR sessions (using 30:2 and CCC) on manikins; sessions were separated by a rest period. We used concealed block randomization to determine CPR method order. Metronome feedback maintained a compression rate of 100/minute. We measured heart rate (HR), mean arterial pressure (MAP), and Borg Exertion Scale. CPR quality measures included total number of compressions and number of adequate compressions (depth ≥5 cm).
  
  
  RESULTS
  Sixty-three participants were enrolled: mean age 70.8 years, female 66.7%, past CPR training 60.3%. Bystander fatigue was similar between CPR methods: mean difference in HR -0.59 (95% CI -3.51-2.33), MAP 1.64 (95% CI -0.23-3.50), and Borg 0.46 (95% CI 0.07-0.84). Compared to 30:2, participants using CCC performed more chest compressions (480.0 v. 376.3, mean difference 107.7; p<0.0001) and more adequate chest compressions (381.5 v. 324.9, mean difference. 62.0; p=0.0001), although good compressions/minute declined significantly faster with the CCC method (p=0.0002).
  
  
  CONCLUSIONS
  CPR quality decreased significantly faster when performing CCC compared to 30:2. However, performing CCC produced more adequate compressions overall with a similar level of fatigue compared to the 30:2 method.
authors.affiliation: *Ottawa Hospital Research Institute,University of Ottawa,Ottawa,ON.
authors.forename: Shawn
authors.initials: S
authors.lastname: Liu
authors.affiliation: *Ottawa Hospital Research Institute,University of Ottawa,Ottawa,ON.
authors.forename: Christian
authors.initials: C
authors.lastname: Vaillancourt
authors.affiliation: *Ottawa Hospital Research Institute,University of Ottawa,Ottawa,ON.
authors.forename: Ann
authors.initials: A
authors.lastname: Kasaboski
authors.affiliation: *Ottawa Hospital Research Institute,University of Ottawa,Ottawa,ON.
authors.forename: Monica
authors.initials: M
authors.lastname: Taljaard
mesh_terms: D000367:Age Factors; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D016001:Confidence Intervals; D018592:Cross-Over Studies; D005221:Fatigue / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000628:therapy*; D006336:Heart Massage / Q000379:methods* / Q000401:mortality; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D009864:Ontario; D011379:Prognosis; D012121:Respiration, Artificial / Q000379:methods; D018570:Risk Assessment; D015996:Survival Rate; D013647:Task Performance and Analysis; D062606:Tertiary Care Centers; D016896:Treatment Outcome
keywords: cardiopulmonary resuscitation; cross-over studies; fatigue