Effects of Head Extension on Peak Airway Pressure During Mask-Ventilation: A Prospective, Randomized, Clinical Single-Centre Trial

Background: Rescuers with basic skills may have difficulties to perform efficient and safe mask ventilation. This study aimed at determining the best head position for ventilation, while avoiding stomach inflation. Methods: Forty healthy patients were mechanically ventilated with a face mask (7 mL.kg). The head was positioned either with n = 20 or without a cushion support (n = 20), and in three different head extension positions. Results: Head angles differed more with no cushion support at 12°; 95% CI 6 18°), 25° (95% CI 17 33°) and 32° (95% CI 27 37°); P < 0.05) when compared with cushion support at 5° (95% CI 3 7°), 16° (95% CI 13 20°), and 22° (95% CI 18 26°); P < 0.05. Without cushion support, peak airway pressure in neutral position was higher (20 cmH2O, 95% CI 17 to 23 cmH2O) than in the anesthesiologist’s favorite position (16 cmH2O, 95% CI 13 to 19 cmH2O; P = 0.000) or in extension (16 ± 7 cmH2O, 95% CI 13 to 19 cmH2O; P = 0.000). Stomach inflation correlated with body mass index in the neutral position, and in the anesthesiologist’s preferred position without