title: Comparison of manually triggered ventilation and bag-valve-mask ventilation during cardiopulmonary resuscitation in a manikin model.
abstract: BACKGROUND
  To compare a novel, pressure-limited, flow adaptive ventilator that enables manual triggering of ventilations (MEDUMAT Easy CPR, Weinmann, Germany) with a bag-valve-mask (BVM) device during simulated cardiac arrest.
  
  
  METHODS
  Overall 74 third-year medical students received brief video instructions (BVM: 57s, ventilator: 126s), standardised theoretical instructions and practical training for both devices. Four days later, the students were randomised into 37 two-rescuer teams and were asked to perform 8min of cardiopulmonary resuscitation (CPR) on a manikin using either the ventilator or the BVM (randomisation list). Applied tidal volumes (V(T)), inspiratory times and hands-off times were recorded. Maximum airway pressures (P(max)) were measured with a sensor connected to the artificial lung. Questionnaires concerning levels of fatigue, stress and handling were evaluated. V(T), pressures and hands-off times were compared using t-tests, questionnaire data were analysed using the Wilcoxon test.
  
  
  RESULTS
  BVM vs. ventilator (mean±SD): the mean V(T) (408±164ml vs. 315±165ml, p=0.10) and the maximum V(T) did not differ, but the number of recorded V(T)<200ml differed (8.1±11.3 vs. 17.0±14.4 ventilations, p=0.04). P(max) did not differ, but inspiratory times (0.80±0.23s vs. 1.39±0.31s, p<0.001) and total hands-off times (133.5±17.8s vs. 162.0±11.1s, p<0.001) did. The estimated levels of fatigue and stress were comparable; however, the BVM was rated to be easier to use (p=0.03).
  
  
  CONCLUSIONS
  For the user group investigated here, this ventilator exhibits no advantages in the setting of simulated CPR and carries a risk of prolonged no-flow time.
authors.affiliation: Emergency Medical Care Section, Department of Anaesthesiology, University Hospital Aachen, RWTH Aachen University, Pauwelsstr. 30, D-52074 Aachen, Germany. sbergrath@ukaachen.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bergrath
authors.forename: Rolf
authors.initials: R
authors.lastname: Rossaint
authors.forename: Henning
authors.initials: H
authors.lastname: Biermann
authors.forename: Max
authors.initials: M
authors.lastname: Skorning
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Beckers
authors.forename: Daniel
authors.initials: D
authors.lastname: Rörtgen
authors.forename: Jörg Ch
authors.initials: JCh
authors.lastname: Brokmann
authors.forename: Christian
authors.initials: C
authors.lastname: Flege
authors.forename: Christina
authors.initials: C
authors.lastname: Fitzner
authors.forename: Michael
authors.initials: M
authors.lastname: Czaplik
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000295:instrumentation* / Q000379:methods*; D004504:Education, Medical, Undergraduate / Q000379:methods; D004867:Equipment Design; D004869:Equipment Safety; D006323:Heart Arrest / Q000628:therapy; D006801:Humans; D017214:Laryngeal Masks; D008348:Manikins; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation / Q000379:methods; D010865:Pilot Projects; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000295:instrumentation* / Q000379:methods*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013337:Students, Medical; D012122:Ventilators, Mechanical