Mutzbauer Till, Tabacek Georg
Department of Craniomaxillofacial Surgery, University of Zurich Dental Center, Zurich, Switzerland.
J Emerg Med. 2010 May;38(4):428-33. doi: 10.1016/j.jemermed.2007.11.034. Epub 2008 May 16.
Gastric inflation is a significant issue when ventilation is performed in cases of unprotected airway. The objective of this study was to compare the amounts of gastric insufflation and tidal volumes produced by a hose-extended bag-valve-mask (BVM) device supplemented by an interposed reservoir bag with a similar BVM without the reservoir in a simulated human model. Fourteen academic dental staff members performed 10 ventilations on a manikin using the reservoir-supplemented device in comparison to the control BVM in a randomized order. Lung compliance was adjusted to 45 (high) and 4.5 mL/mbar (low), and the lower esophageal sphincter pressure (LOSP) simulator to a pressure of 15 and 3 mbar, respectively, in different settings. Lower tidal volumes were observed with the new device than with the control BVM at high compliance with LOSP of 15 mbar (median 506 vs. 787 mL, respectively; p = 0.0002) and LOSP of 3 mbar (median 544 vs. 794 mL, respectively; p = 0.0006), as well as during ventilation at low lung compliance and LOSP of 3mbar (median 131 vs. 163 mL, respectively; p = 0.0342). No differences were detected at low lung compliance and LOSP of 15 mbar (median 175 vs. 194 mL; p = 0.3804). Gastric inflation almost exclusively occurred in case of low lung compliance, being markedly lower with the new device than with the control device at 15 mbar LOSP (300 vs. 2225 mL, respectively; p = 0.0006), and at 3 mbar LOSP (1138 vs. 3050 mL, respectively; p = 0.0001). Application of the hose-extended bag-valve-mask device supplemented with a reservoir bag reduces tidal volumes. Marked reduction of gastric inflation by use of this device becomes effective under conditions with low lung compliance.
在气道无保护的情况下进行通气时，胃充气是一个重要问题。本研究的目的是在模拟人体模型中，比较配备插入式贮气囊的软管延长型袋阀面罩（BVM）装置与未配备贮气囊的类似BVM所产生的胃内充气量和潮气量。14名牙科专业人员按照随机顺序，使用配备贮气囊的装置与对照BVM在人体模型上进行10次通气。在不同设置中，将肺顺应性分别调整为45（高）和4.5 mL/mbar（低），并将食管下括约肌压力（LOSP）模拟器分别调整为15和3 mbar。在高顺应性且LOSP为15 mbar时（中位数分别为506 vs. 787 mL；p = 0.0002）以及LOSP为3 mbar时（中位数分别为544 vs. 794 mL；p = 0.0006），与对照BVM相比，新装置观察到的潮气量更低，在低肺顺应性且LOSP为3 mbar的通气过程中也是如此（中位数分别为131 vs. 163 mL；p = 0.0342）。在低肺顺应性且LOSP为15 mbar时未检测到差异（中位数为175 vs. 194 mL；p = 0.3804）。胃充气几乎仅在低肺顺应性情况下发生，在15 mbar LOSP时，新装置的胃充气量明显低于对照装置（分别为300 vs. 2225 mL；p = 0.0006），在3 mbar LOSP时也是如此（分别为1138 vs. 3050 mL；p = 0.0001）。应用配备贮气囊的软管延长型袋阀面罩装置可减少潮气量。在低肺顺应性条件下，使用该装置可显著减少胃充气。
