Effect of different airway devices on ventilation during cardiopulmonary resuscitation

Abstract

Purpose: This study compared face mask, supraglottic airway device (SGA), and endotracheal tube (ETT) ventilation with mechanical ventilation (MV) during cardiopulmonary resuscitation (CPR) in the flat position and with head and thorax elevation (HTE).

Methods: Using thawed, fresh-frozen human cadavers this randomized cross-over study compared face mask, SGA, and ETT ventilation using an automated ventilator in the flat and HTE positions. Tidal volume (TV) was set to 8 mL/kg ideal predicted body weight, and expiratory TV (VTe) (mL/kg) was the primary endpoint. Secondary endpoints included inspiratory TV (VTi), maximal inspiratory airway pressure (Pmax), and leakage between inspiratory and expiratory tidal volumes (VTi-VTe).

Results: Data from 8 cadavers and 2302 ventilation cycles were analyzed. In the flat position, VTe was 7.66 ± 3.75 with ETT, 5.01 ± 3.14 with SGA, and 5.63 ± 2.83 with face mask, respectively. A mixed linear model showed the airway device significantly impacted VTe, VTi, Pmax, and VTi-VTe (p < 0.001 for each). Compared with intubation, both face mask and SGA ventilation resulted in lower VTe, lower Pmax, and higher VTi-VTe (p < 0.001 for each). No significant differences were observed between face mask and SGA ventilation. There were higher VTe and lower VTi-VTe values (p < 0.001 for each) with HTE versus the flat position (p < 0.001).

Conclusions: In human cadavers undergoing CPR, mechanical ventilation through a face mask or SGA versus an ETT was associated with lower VTe, lower Pmax, and higher leakage values in human cadavers during CPR. Head and thorax elevation reduce face mask and SGA airway leakage during CPR and increase VTe.

Keywords: Cardiopulmonary resuscitation; Heart arrest; Mechanical ventilation; Respiratory mechanics; Respiratory physiology.