Department of Anaesthesia, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China.
Department of Anaesthesiology.
Br J Anaesth. 2017 Apr 1;118(4):618-624. doi: 10.1093/bja/aex035.
BACKGROUND.: Mask ventilation and tracheal intubation are basic techniques for airway management and mutually inclusive rescue measures to restore ventilation. The aim of this study was to compare the effectiveness of mask ventilation between two commonly used techniques of two-handed mask ventilation in obese unconscious apnoeic adults.
METHODS.: Eighty-one obese adults received mask ventilation after induction using C-E clamp and modified V-E clamp techniques in a randomized crossover manner. Mechanical ventilation was provided using a pressure-control mode, at a rate of 10 bpm, with an inspiratory-to-expiratory time ratio of 1:2 and a pre-set plateau airway pressure of 20 cm H 2 O. The primary outcome was expired tidal volume.
RESULTS.: The BMI for the subjects was 37 ( sd 4.9) kg m -2 . The failure rates for mask ventilation (tidal volume≤anatomical dead space) were 44% for the C-E technique and 0% for the V-E technique ( P <0.001). Tidal volume was significantly lower for the C-E than the V-E technique [371 ( sd 345) vs 720 (244) ml, P <0.001]. The peak airway pressures were 21 ( sd 1.5) cm H 2 O for the C-E technique and 21 (1.3) cm H 2 O for the V-E technique.
CONCLUSIONS.: Mask ventilation using the modified V-E technique is more effective than with the C-E technique in unconscious obese apnoeic adults. Subjects who fail ventilation with the C-E technique can be ventilated effectively with the V-E technique.
CLINICAL TRIAL REGISTRATION.: NCT02580526.
面罩通气和气管插管是气道管理的基本技术，也是相互包容的恢复通气的抢救措施。本研究旨在比较两种常用的双手面罩通气技术在肥胖无意识窒息成人中的面罩通气效果。
81 名肥胖成年人在诱导后采用 C-E 夹和改良 V-E 夹技术以随机交叉方式接受面罩通气。机械通气采用压力控制模式，呼吸频率为 10 次/分，吸呼比为 1:2，预设平台气道压为 20cmH2O。主要结局为呼气潮气量。
受试者的 BMI 为 37（sd4.9）kg/m2。C-E 技术面罩通气失败率（潮气量≤解剖死腔）为 44%，V-E 技术为 0%（P<0.001）。C-E 技术的潮气量明显低于 V-E 技术[371（sd345）vs720（244）ml，P<0.001]。C-E 技术的气道峰压为 21（sd1.5）cmH2O，V-E 技术为 21（1.3）cmH2O。
在无意识肥胖窒息的成年人中，改良的 V-E 技术的面罩通气比 C-E 技术更有效。C-E 技术通气失败的患者可以通过 V-E 技术有效通气。
NCT02580526。
