title: The specific effect of metronome guidance on the quality of one-person cardiopulmonary resuscitation and rescuer fatigue.
abstract: BACKGROUND
  Metronome guidance is a simple and economic feedback method of guiding cardiopulmonary resuscitation (CPR). It has been proven for its usefulness in regulating the rate of chest compression and ventilation, but it is not yet clear how metronome use may affect compression depth or rescuer fatigue.
  
  
  OBJECTIVE
  The aim of this study was to assess the specific effect that metronome guidance has on the quality of CPR and rescuer fatigue.
  
  
  METHODS
  One-person CPRs were performed by senior medical students on Resusci Anne® manikins (Laerdal, Stavanger, Norway) with personal-computer skill-reporting systems. Half of the students performed CPR with metronome guidance and the other half without. CPR performance data, duration, and before-after trial differences in mean arterial pressure (MAP) and heart rate (HR) were compared between groups.
  
  
  RESULTS
  Average compression depth (ACD) of the first five cycles, compression rate, no-flow fraction, and ventilation count were significantly lower in the metronome group (p=0.028, < 0.001, 0.001, and 0.041, respectively). Total CPR duration, total work (ACD × total compression count), and the before-after trial differences of the MAP and HR did not differ between the two groups.
  
  
  CONCLUSIONS
  Metronome guidance is associated with lower chest compression depth of the first five cycles, while shortening the no-flow fraction and the ventilation count in a simulated one-person CPR model. Metronome guidance does not have an obvious effect of intensifying rescuer fatigue.
authors.affiliation: Department of Emergency Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Tae Nyoung
authors.initials: TN
authors.lastname: Chung
authors.forename: Sun Wook
authors.initials: SW
authors.lastname: Kim
authors.forename: Je Sung
authors.initials: JS
authors.lastname: You
authors.forename: Young Soon
authors.initials: YS
authors.lastname: Cho
authors.forename: Sung Phil
authors.initials: SP
authors.lastname: Chung
authors.forename: Incheol
authors.initials: I
authors.lastname: Park
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000328:Adult; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D005221:Fatigue; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D008348:Manikins; D055815:Young Adult