Yealy D M, Plewa M C, Stewart R D
Division of Emergency Medicine, University of Pittsburgh.
Am J Emerg Med. 1991 Jan;9(1):20-3. doi: 10.1016/0735-6757(91)90006-6.
The authors evaluated the cannulae and oxygen sources available for pediatric translaryngeal ventilation. Peak flow rates were measured and maximum tidal volumes (MTV) calculated for each combination of cannula and oxygen source. Standard 22, 20, 18, and 16 gauge intravenous catheters and a 14 gauge cannula designed for pediatric jet ventilation were tested. The oxygen sources evaluated included an adult bag-valve device; a continuous flow source regulated between 6 to 15 L/min; and a high pressure jet source regulated between 5 to 50 psi. Mean calculated MTV delivered to the cannula tip (22 g to 14 g) were: 26 to 235 mL with the bag-valve source; 91 to 236 mL with the continuous flow sources; and 58 to 1034 mL with the jet sources. Assuming that in normal subjects approximately 70% of the flow from the tip of a translaryngeal cannula reaches the distal respiratory tree, the authors conclude that bag-valve and continuous flow low pressure sources are unlikely to deliver sufficient tidal volumes to sustain normal ventilation in apneic children when coupled with standard cannulae. Jet oxygen sources with standard cannulae provide a wide range of tidal volumes sufficient to sustain normal ventilation in apneic pediatric patients.
作者评估了可用于小儿经喉通气的插管和氧气源。测量了每种插管与氧气源组合的峰值流速，并计算了最大潮气量（MTV）。测试了标准的22号、20号、18号和16号静脉导管以及一种专为小儿喷射通气设计的14号插管。评估的氧气源包括成人麻醉面罩装置；流速在6至15升/分钟之间调节的持续气流源；以及压力在5至50磅力/平方英寸之间调节的高压喷射源。输送至插管尖端（22号至14号）的平均计算MTV为：使用麻醉面罩源时为26至235毫升；使用持续气流源时为91至236毫升；使用喷射源时为58至1034毫升。假设在正常受试者中，经喉插管尖端约70%的气流能到达远端呼吸树，作者得出结论，当与标准插管配合使用时，麻醉面罩和持续气流低压源不太可能输送足够的潮气量以维持呼吸暂停儿童的正常通气。标准插管与喷射氧气源可提供足以维持呼吸暂停小儿患者正常通气的广泛潮气量范围。
