Mask Ventilation during Induction of General Anesthesia: Influences of Obstructive Sleep Apnea

• Published in: Anesthesiology (Philadelphia) Vol. 126; no. 1; pp. 28 - 38
• Main Authors: Sato, Shin, Hasegawa, Makoto, Okuyama, Megumi, Okazaki, Junko, Kitamura, Yuji, Sato, Yumi, Ishikawa, Teruhiko, Sato, Yasunori, Isono, Shiroh
• Format: Journal Article
• Language: English
• Published: United States Copyright by , the American Society of Anesthesiologists, Inc. Wolters Kluwer Health, Inc 01.01.2017
• Subjects: Adult; Aged; Aged, 80 and over; Anesthesia, General - methods; Female; Humans; Male; Masks; Middle Aged; Respiration, Artificial - instrumentation; Respiration, Artificial - methods; Sleep Apnea, Obstructive - physiopathology; Tidal Volume - physiology; Young Adult
• ISSN: 0003-3022; 1528-1175; 1528-1175
• DOI: 10.1097/ALN.0000000000001407

BACKGROUND:Depending on upper airway patency during anesthesia induction, tidal volume achieved by mask ventilation may vary. In 80 adult patients undergoing general anesthesia, the authors tested a hypothesis that tidal volume during mask ventilation is smaller in patients with sleep-disordered breathing priorly defined as apnea hypopnea index greater than 5 per hour. METHODS:One-hand mask ventilation with a constant ventilator setting (pressure-controlled ventilation) was started 20 s after injection of rocuronium and maintained for 1 min during anesthesia induction. Mask ventilation efficiency was assessed by the breath number needed to initially exceed 5 ml/kg ideal body weight of expiratory tidal volume (primary outcome) and tidal volumes (secondary outcomes) during initial 15 breaths (UMIN000012494). RESULTS:Tidal volume progressively increased by more than 70% in 1 min and did not differ between sleep-disordered breathing (n = 42) and non–sleep-disordered breathing (n = 38) patients. In post hoc subgroup analyses, the primary outcome breath number (mean [95% CI], 5.7 [4.1 to 7.3] vs. 1.7 [0.2 to 3.2] breath; P = 0.001) and mean tidal volume (6.5 [4.6 to 8.3] vs. 9.6 [7.7 to 11.4] ml/kg ideal body weight; P = 0.032) were significantly smaller in 20 sleep-disordered breathing patients with higher apnea hypopnea index (median [25th to 75th percentile]21.7 [17.6 to 31] per hour) than in 20 non–sleep disordered breathing subjects with lower apnea hypopnea index (1.0 [0.3 to 1.5] per hour). Obesity and occurrence of expiratory flow limitation during one-hand mask ventilation independently explained the reduction of efficiency of mask ventilation, while the use of two hands effectively normalized inefficient mask ventilation during one-hand mask ventilation. CONCLUSIONS:One-hand mask ventilation is difficult in patients with obesity and severe sleep-disordered breathing particularly when expiratory flow limitation occurs during mask ventilation.