Comparison of manually triggered ventilation and bag-valve-mask ventilation during cardiopulmonary resuscitation in a manikin model.

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).

Conclusion: 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.