Comparison of bag-valve-mask, manually triggered ventilator, and automated ventilator devices used while ventilating a nonintubated mannikin model

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-valvemask (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.

Keywords:

• ventilation
• prehospital care
• bag-valve-mask.