title: Rescuer fatigue: standard versus continuous chest-compression cardiopulmonary resuscitation.
abstract: OBJECTIVE
  Continuous chest-compression cardiopulmonary resuscitation (CCC-CPR) has been advocated as an alternative to standard CPR (STD-CPR). Studies have shown that CCC-CPR delivers substantially more chest compressions per minute and is easier to remember and perform than STD-CPR. One concern regarding CCC-CPR is that the rescuer may fatigue and be unable to maintain adequate compression rate or depth throughout an average emergency medical services response time. The specific aim of this study was to compare the effects of fatigue on the performance of CCC-CPR and STD-CPR on a manikin model.
  
  
  METHODS
  This was a prospective, randomized crossover study involving 53 medical students performing CCC-CPR and STD-CPR on a manikin model. Students were randomized to their initial CPR group and then performed the other type of CPR after a period of at least two days. Students were evaluated on their performance of 9 minutes of CPR for each method. The primary endpoint was the number of adequate chest compressions (at least 38 mm of compression depth) delivered per minute during each of the 9 minutes. The secondary endpoints were total compressions, compression rate, and the number of breaks taken for rest. The students' performance was evaluated on the basis of Skillreporter Resusci Anne (Laerdal, Wappingers Falls, NY) recordings. Primary and secondary endpoints were analyzed by using the generalized linear mixed model for counting data.
  
  
  RESULTS
  In the first 2 minutes, participants delivered significantly more adequate compressions per minute with CCC-CPR than STD-CPR, (47 vs. 32, p = 0.004 in the 1st minute and 39 vs. 29, p = 0.04 in the 2nd minute). For minutes 3 through 9, the differences in number of adequate compressions between groups were not significant. Evaluating the 9 minutes of CPR as a whole, there were significantly more adequate compressions in CCC-CPR vs. STD-CPR (p = 0.0003). Although the number of adequate compressions per minute declined over time in both groups, the rate of decline was significantly greater in CCC-CPR compared with STD-CPR (p = 0.0003). The mean number of total compressions delivered in the first minute was significantly greater with CCC-CPR than STD-CPR (105 per minute vs. 58 per minute, p < 0.001) and did not change over 9 minutes in either group. There were no differences in compression rates or number of breaks between groups.
  
  
  CONCLUSIONS
  CCC-CPR resulted in more adequate compressions per minute than STD-CPR for the first 2 minutes of CPR. However, the difference diminished after 3 minutes, presumably as a result of greater rescuer fatigue with CCC-CPR. Overall, CCC-CPR resulted in more total compressions per minute than STD-CPR during the entire 9 minutes of resuscitation.
authors.affiliation: Department of Emergency Medicine, Scott & White Hospital, 2401 South 31st Street, Temple, TX 76508, USA. phojesco@yahoo.com
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Heidenreich
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Travis A
authors.initials: TA
authors.lastname: Higdon
authors.forename: Gordon A
authors.initials: GA
authors.lastname: Ewy
authors.forename: Karl B
authors.initials: KB
authors.lastname: Kern
authors.forename: Arthur B
authors.initials: AB
authors.lastname: Sanders
mesh_terms: D000328:Adult; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D018592:Cross-Over Studies; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D018763:Muscle Fatigue