Head elevation and lateral head rotation effect on facemask ventilation efficiency: Randomized crossover trials

We performed two prospective randomized crossover trials to evaluate the effect of head elevation or lateral head rotation to facemask ventilation volume.In the first trial, facemask ventilation was performed with a 12-cm high pillow (HP) and 4-cm low pillow (LP) in 20 female patients who were scheduled to undergo general anesthesia. In the second trial, facemask ventilation was performed with and without lateral head rotation in another 20 female patients. Ventilation volume was measured in a pressure-controlled ventilation (PCV) manner at 10, 15, and 20 cmH2O inspiratory pressures.In the first trial evaluating head elevation effect, facemask ventilation volume was significantly higher with a HP than with a LP at 15 and 20 cmH2O inspiratory pressure (15 cmH2O: HP median540 [IQR480-605] mL, LP 460 [400-520] mL, P=0.006, 20 cmH2O: HP 705 [650-800] mL, LP 560 [520-677] mL, P<0.001). In the second trial, lateral head rotation did not significantly increase facemask ventilation volume at all inspiratory pressure.Head elevation increased facemask ventilation volume in normal airway patients, while lateral head rotation did not.