Hamaekers Ankie, Borg Pieter, Enk Dietmar
Department of Anesthesiology, Maastricht University Medical Centre, PO Box 5800, Maastricht 6202 AZ, The Netherlands.
Paediatr Anaesth. 2009 May;19(5):452-7. doi: 10.1111/j.1460-9592.2008.02830.x. Epub 2009 Nov 24.
Several self-assembled devices, consisting of a three-way stopcock connected to a high pressure oxygen source, have been proposed for transtracheal jet ventilation in an emergency situation. As a three-way stopcock acts as a 'flow splitter' it will, when connected to a continuous oxygen flow, never ensure total flow and pressure release through its side port. The aim of the present study was to measure the efficacy of flow and pressure release of three previously described self-assembled jet devices and one commercially available tool.
In a laboratory setting simulating an obstructed upper airway the generated pressure at the cannula tip (PACT) during the expiration phase was measured in three self-assembled jet devices consisting of a three-way stopcock with an inner diameter of 2 mm (device A), 2.5 mm (device B), and 3 mm (device C), respectively, and in the Oxygen Flow Modulator (OFM) at oxygen flows of 6, 9, 12, and 15 l min(-1).
The PACT of device A at on oxygen flow of 15 l min(-1) was 71.1 (+/-0.08) cm H(2)O. At a reduced flow of 9 l min(-1) the PACT of device A was still 25.8 (+/-0.08) cm H2O. In device B and C the PACT was 35.6 (+/-0.04) and 17.6 (+/-0.04) cm H2O, respectively, at an oxygen flow of 15 l.min(-1). In contrast, the PACT in the OFM (five side holes open) was 4.4 (+/-0.02) cm H2O at the same flow.
In case of complete upper airway obstruction the OFM provides sufficient flow and pressure release, whereas the self-assembled jet devices tested are inherently dangerous constructions.
已经提出了几种由连接到高压氧气源的三通旋塞组成的自组装装置，用于紧急情况下的经气管喷射通气。由于三通旋塞起到“分流器”的作用，当连接到连续氧气流时，它永远无法确保通过其侧端口实现总流量和压力释放。本研究的目的是测量三种先前描述的自组装喷射装置和一种市售工具的流量和压力释放效果。
在模拟上呼吸道阻塞的实验室环境中，分别在三种由内径为2毫米（装置A）、2.5毫米（装置B）和3毫米（装置C）的三通旋塞组成的自组装喷射装置以及氧气流量调节器（OFM）中，在氧气流量为6、9、12和15升/分钟的情况下，测量呼气阶段套管尖端处产生的压力（PACT）。
装置A在氧气流量为15升/分钟时的PACT为71.1（±0.08）厘米水柱。在流量降至9升/分钟时，装置A的PACT仍为25.8（±0.08）厘米水柱。在装置B和C中，氧气流量为15升/分钟时的PACT分别为35.6（±0.04）和17.6（±0.04）厘米水柱。相比之下，在相同流量下，OFM（五个侧孔打开）中的PACT为4.4（±0.02）厘米水柱。
在上呼吸道完全阻塞的情况下，OFM可提供足够的流量和压力释放，而测试的自组装喷射装置本质上是危险的构造。
