title: Influence of chest compression rate guidance on the quality of cardiopulmonary resuscitation performed on manikins.
abstract: OBJECTIVE
  The adequate chest compression rate during CPR is associated with improved haemodynamics and primary survival. To explore whether the use of a metronome would affect also chest compression depth beside the rate, we evaluated CPR quality using a metronome in a simulated CPR scenario.
  
  
  METHODS
  Forty-four experienced intensive care unit nurses participated in two-rescuer basic life support given to manikins in 10min scenarios. The target chest compression to ventilation ratio was 30:2 performed with bag and mask ventilation. The rescuer performing the compressions was changed every 2min. CPR was performed first without and then with a metronome that beeped 100 times per minute. The quality of CPR was analysed with manikin software. The effect of rescuer fatigue on CPR quality was analysed separately.
  
  
  RESULTS
  The mean compression rate between ventilation pauses was 137+/-18compressions per minute (cpm) without and 98+/-2cpm with metronome guidance (p<0.001). The mean number of chest compressions actually performed was 104+/-12cpm without and 79+/-3cpm with the metronome (p<0.001). The mean compression depth during the scenario was 46.9+/-7.7mm without and 43.2+/-6.3mm with metronome guidance (p=0.09). The total number of chest compressions performed was 1022 without metronome guidance, 42% at the correct depth; and 780 with metronome guidance, 61% at the correct depth (p=0.09 for difference for percentage of compression with correct depth).
  
  
  CONCLUSIONS
  Metronome guidance corrected chest compression rates for each compression cycle to within guideline recommendations, but did not affect chest compression quality or rescuer fatigue.
authors.affiliation: Department of Anaesthesia and Intensive Care, Kuopio University Hospital, PO Box 1777, FIN-70210 Kuopio, Finland. helena.jantti@kuh.fi
authors.forename: H
authors.initials: H
authors.lastname: Jäntti
authors.forename: T
authors.initials: T
authors.lastname: Silfvast
authors.forename: A
authors.initials: A
authors.lastname: Turpeinen
authors.forename: V
authors.initials: V
authors.lastname: Kiviniemi
authors.forename: A
authors.initials: A
authors.lastname: Uusaro
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001291:Attitude of Health Personnel; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000451:nursing; D003422:Critical Care; D018592:Cross-Over Studies; D005221:Fatigue / Q000209:etiology; D005260:Female; D006336:Heart Massage; D006801:Humans; D008297:Male; D008348:Manikins; D008875:Middle Aged; D010507:Periodicity; D011787:Quality of Health Care; D055815:Young Adult