Osterwalder J J, Schuhwerk W
Department of Emergency and Surgery, Kantonsspital, St. Gallen, Switzerland.
Resuscitation. 1998 Jan;36(1):23-7. doi: 10.1016/s0300-9572(97)00091-9.
The demands for an optimal ventilation apparatus are that it can be easily handled, achieves a sufficiently high ventilation volume, and minimizes gastric inflation. Our aim was therefore to carry out a study in a training mannikin to find out whether the Oxylator EM100, compared with the bag, obtains improved ventilation and a decrease in gastric inflation. In a randomized crossover study, 72 subjects were selected (24 physicians, 44 nurses and 4 auxiliary nurses), chosen from the operating theatre, emergency department and intensive care unit of two hospitals. We used the Ambu-Bag Mark III with mask No. 4, the Oxylator EM100 with a pressure setting of 35 cm H2O run in the manual setting, the Ambu-Man C mannikin as well as the Ambu-CPR computer program. The resuscitation cycles of the standard two-rescuer's adult procedure lasted 3 min each, with a 3-min pause between the crossover procedure. The participants could improve their ventilatory volume with the Oxylator EM100 by 635 ml (95% confidence interval 578-692 ml) compared with the bag ventilation. The number of subjects who could attain a mean ventilatory volume of 800 ml or more increased from 15% to 98.6% (P < 0.001). Compared with the bag, the increase of adequate respirations (> or = 800 ml) obtained by the Oxylator EM100 for the individual participants amounted to a median of 91% (P < 0.001). Moreover, conventional ventilation caused in 42% one or several instances of gastric inflation, whereas no such reactions occurred with the Oxylator EM100. The Oxylator EM100 showed significantly better results in the mannikin than the bag. Of most importance is a significant lowering of gastric inflation and less so a marked increase in ventilatory volume. Our trial procedure with a relatively high lung compliance and a high oesophageal sphincter opening simulated favorable conditions. Owing to a large in vivo variability of these magnitudes, a direct testing in real patients with circulatory arrest is indicated.
对最佳通气设备的要求是操作简便、通气量足够高且能使胃胀气最小化。因此，我们的目的是在训练人体模型上进行一项研究，以确定与气囊相比，Oxylator EM100是否能改善通气并减少胃胀气。在一项随机交叉研究中，从两家医院的手术室、急诊科和重症监护病房挑选了72名受试者（24名医生、44名护士和4名辅助护士）。我们使用了带有4号面罩的Ambu - Bag Mark III、手动设置压力为35 cm H₂O的Oxylator EM100、Ambu - Man C人体模型以及Ambu - CPR计算机程序。标准的两名施救者成人操作的复苏周期每次持续3分钟，交叉操作之间有3分钟的停顿。与气囊通气相比，使用Oxylator EM100时，参与者的通气量可增加635 ml（95%置信区间578 - 692 ml）。能够达到平均通气量800 ml或更高的受试者数量从15%增加到98.6%（P < 0.001）。与气囊相比，Oxylator EM100使个体参与者获得的有效呼吸（≥800 ml）增加量中位数为91%（P < 0.001）。此外，传统通气导致42%的受试者出现一次或多次胃胀气情况，而Oxylator EM100未出现此类反应。在人体模型中，Oxylator EM100的效果明显优于气囊。最重要的是胃胀气显著减少，通气量的显著增加则次之。我们的试验程序模拟了肺顺应性相对较高和食管括约肌开口较大的有利条件。由于这些指标在体内的变异性很大，因此有必要在实际的循环骤停患者中进行直接测试。
