Dörges V, Ocker H, Hagelberg S, Wenzel V, Idris A H, Schmucker P
Department of Anaesthesiology, Medical University of Lübeck, 23562 Lübeck, Ratzeburger Allee, Germany.
Resuscitation. 2000 Mar;44(1):37-41. doi: 10.1016/s0300-9572(99)00161-6.
The European Resuscitation Council has recommended decreasing tidal volume during basic life support ventilation from 800 to 1200 ml, as recommended by the American Heart Association, to 500 ml in order to minimise stomach inflation. However, if oxygen is not available at the scene of an emergency, and small tidal volumes are given during basic life support ventilation with a paediatric self-inflatable bag and room-air (21% oxygen), insufficient oxygenation and/or inadequate ventilation may result. When apnoea occurred after induction of anaesthesia, 40 patients were randomly allocated to room-air ventilation with either an adult (maximum volume, 1500 ml) or paediatric (maximum volume, 700 ml) self-inflatable bag for 5 min before intubation. When using an adult (n=20) versus paediatric (n=20) self-inflatable bag, mean +/-SEM tidal volumes and tidal volumes per kilogram were significantly (P<0.0001) larger (719+/-22 vs. 455+/-23 ml and 10.5+/-0.4 vs. 6.2+/-0.4 ml kg(-1), respectively). Compared with an adult self-inflatable bag, bag-valve-mask ventilation with room-air using a paediatric self-inflatable bag resulted in significantly (P<0.01) lower paO(2) values (73+/-4 vs. 87+/-4 mmHg), but comparable carbon dioxide elimination (40+/-2 vs. 37+/-1 mmHg; NS). In conclusion, our results indicate that smaller tidal volumes of approximately 6 ml kg(-1) ( approximately 500 ml) given with a paediatric self-inflatable bag and room-air maintain adequate carbon dioxide elimination, but do not result in sufficient oxygenation during bag-valve-mask ventilation. Thus, if small (6 ml kg(-1)) tidal volumes are being used during bag-valve-mask ventilation, additional oxygen is necessary. Accordingly, when additional oxygen during bag-valve-mask ventilation is not available, only large tidal volumes of approximately 11 ml kg(-1) were able to maintain both sufficient oxygenation and carbon dioxide elimination.
欧洲复苏委员会已建议，在基础生命支持通气期间，将潮气量从美国心脏协会推荐的800至1200毫升降至500毫升，以尽量减少胃胀气。然而，如果在紧急现场没有氧气，且使用儿科自动充气式气囊并以室内空气（21%氧气）进行基础生命支持通气时给予小潮气量，则可能导致氧合不足和/或通气不足。麻醉诱导后出现呼吸暂停时，40例患者在插管前被随机分配，分别使用成人（最大容量1500毫升）或儿科（最大容量700毫升）自动充气式气囊以室内空气进行通气5分钟。使用成人（n = 20）与儿科（n = 20）自动充气式气囊时，平均±标准误潮气量和每千克潮气量显著更大（分别为719±22与455±23毫升以及10.5±0.4与6.2±0.4毫升·千克⁻¹，P<0.0001）。与成人自动充气式气囊相比，使用儿科自动充气式气囊以室内空气进行袋 - 阀 - 面罩通气导致动脉血氧分压（PaO₂）值显著更低（73±4与87±4毫米汞柱，P<0.01），但二氧化碳清除情况相当（40±2与37±1毫米汞柱；无显著差异）。总之，我们的结果表明，使用儿科自动充气式气囊并以室内空气给予约6毫升·千克⁻¹（约500毫升）的较小潮气量可维持足够的二氧化碳清除，但在袋 - 阀 - 面罩通气期间不能实现充分氧合。因此，如果在袋 - 阀 - 面罩通气期间使用小（6毫升·千克⁻¹）潮气量，则需要额外的氧气。相应地，当袋 - 阀 - 面罩通气期间没有额外氧气时，只有约11毫升·千克⁻¹的大潮气量能够维持充分的氧合和二氧化碳清除。
