ABSTRACT
OBJECTIVE: To determine whether 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 nonintubated mannikin with a bag-valve-mask (BV), manually triggered ventilator (MTV), and automated ventilator (AV). The authors' hypothesis was that there would be no differences among the 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 nonintubated mannikin-mechanical test lung model with the 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 2 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. A survey was issued to the EMTs who participated in the study. Data were analyzed with repeated-measures ANOVA and the Bonferroni-Dunn multiple comparison test with alpha set at 0.05. RESULTS: At the normal compliance, PAP was higher for the BV than the MTV (p = 0.0001) and AV (p < 0.0001). MV was also greater with the BV than with the AV (p = 0.001). PAP was also higher at the poor compliance with the BV than with the MTV and AV (p = 0.008 and 0.013, respectively). The BV had a higher GI at this compliance (p < 0.0001) and a higher ML than the AV (p = 0.002). CONCLUSION: All three devices delivered similar volumes when used by EMTs, but the BV was associated with higher PAP, ML, and GI.
