Purpose: The purpose of this study was to determine if there were differences in tidal volume (Vt), minute volume (MV), average mask leak per breath (ML), gastric insufflation (GI), and peak airway pressure (PAP) when ventilating a non-intubated mannikin with a bag-valve (BV), manually triggered ventilator (MTV) and automated ventilator (AV). Our hypothesis was that there would be no differences among devices for any of these variables.Methods: This was a prospective in vitro experimental model. A convenience sample of 19 emergency medical technicians (EMTs) ventilated a non-intubated mannikin-mechanical test lung model with BV, MTV (flow rate 40 L/min; pressure relief 55 cm H2O), and AV (800 ml/breath; rate 12). Each subject, blinded to volume and pressure gauges, used each device for two minutes at both normal (0.1 cm H2O) and poor (0.04 cm H2O) compliances. Vt, MV, GI, and PAP were measured directly and ML was calculated. Data were analyzed with repeated measures ANOVA and Bonferoni-Dunn multiple comparison test with alpha set at 0.05.
High-frequency percussive ventilation at altitude: study in a hypobaric chamber with a mechanical test lung
