Winship S, Skinner A
University Department of Anaesthesia, Royal Liverpool and Broad Green University Hospital.
Br J Anaesth. 1998 Nov;81(5):787-9. doi: 10.1093/bja/81.5.787.
We have measured oxygen wash-in in 20 volunteers undergoing preoxygenation with a face mask, mouthpiece alone and a mouthpiece with a noseclip, in a crossover study. Tidal volume breathing and maximal deep breath techniques were studied with each type of equipment. When tidal volume breathing was used, the face mask and mouthpiece with noseclip were comparable, but the mouthpiece alone achieved a lower end-expiratory oxygen concentration than the two other methods after 3 min (P < 0.001 and P < 0.01), and after 5 min (P < 0.05 in each case). Conversely, during preoxygenation with vital capacity breaths, the mouthpiece and mouthpiece with noseclip were comparable, and both were more effective than the face mask (P < 0.001). In a second study, 20 patients who had undergone preoxygenation before induction of anaesthesia were asked later if they would have preferred the face mask or mouthpiece for this procedure. Significantly more patients (14 of 18 who expressed a preference) favoured the mouthpiece (P < 0.05; confidence limits 0.56-0.92).
在一项交叉研究中，我们对20名志愿者进行了面罩预给氧、仅使用咬嘴以及使用带鼻夹咬嘴时的氧冲洗情况进行了测量。使用每种设备时，研究了潮气量呼吸和最大深呼吸技术。当采用潮气量呼吸时，面罩和带鼻夹咬嘴的效果相当，但仅使用咬嘴在3分钟后（P < 0.001和P < 0.01）以及5分钟后（每种情况P < 0.05）的呼气末氧浓度低于其他两种方法。相反，在进行肺活量呼吸预给氧时，咬嘴和带鼻夹咬嘴效果相当，且两者均比面罩更有效（P < 0.001）。在第二项研究中，询问了20名在麻醉诱导前接受过预给氧的患者，他们之后是否会选择面罩或咬嘴进行该操作。明显更多患者（表达偏好的18名患者中有14名）更喜欢咬嘴（P < 0.05；置信区间0.56 - 0.92）。
