Ho A M H
Department of Anesthesiology and Perioperative Medicine, Queen's University, Kingston General Hospital, Kingston, Ontario, Canada.
Anaesth Intensive Care. 2014 May;42(3):330-2. doi: 10.1177/0310057X1404200309.
If tracheal intubation is not possible using direct laryngoscopy, one option is to use a laryngeal mask airway (LMA) through which an endotracheal tube (ETT) can be passed. In children, however, the size of an uncuffed ETT that can pass through the lumen of an LMA is sometimes too small for the trachea, resulting in gas leakage around the ETT. Using a cuffed ETT may reduce the gas leak but withdrawal of the LMA is then prevented by the pilot balloon. In this study, the largest sizes of cuffed and uncuffed Mallinckrodt™ ETTs that could pass with ease through various sizes of paediatric Classic™ and ProSeal™ LMAs were documented. For cuffed ETTs, withdrawal of the LMA was made possible by simply cutting off the pilot balloon. The ETT cuff-inflating mechanism was then repaired by passing a 20 or 22 gauge cannula into the cut end of the inflating tubing. The proximal end of the cannula was then connected to a one-way valve or a three-way stopcock. This technique of cutting off the pilot balloon of the cuffed ETT made it possible to use paediatric cuffed ETTs in exchange for the LMAs tested. The task was easy to perform. Subsequent repair of the cuff-inflation tubing was effective and could withstand high pressures. These findings indicate that it is possible to pass cuffed ETTs through paediatric LMA lumens, which can provide ventilation without gas leaks, unlike uncuffed ETTs.
如果使用直接喉镜无法进行气管插管，一种选择是使用喉罩气道（LMA），通过它可以插入气管内导管（ETT）。然而，在儿童中，能够通过LMA管腔的无套囊ETT的尺寸有时对于气管来说太小，导致ETT周围漏气。使用带套囊的ETT可能会减少漏气，但导气管囊会阻止LMA拔出。在本研究中，记录了能够轻松通过各种尺寸的儿科Classic™和ProSeal™ LMA的最大尺寸的带套囊和无套囊的Mallinckrodt™ ETT。对于带套囊的ETT，只需切断导气管囊就可以拔出LMA。然后通过将20或22号套管插入充气管的切割端来修复ETT套囊充气机制。然后将套管的近端连接到单向阀或三通旋塞。这种切断带套囊ETT导气管囊的技术使得可以使用儿科带套囊ETT来替换所测试的LMA。该操作易于执行。随后对套囊充气管的修复是有效的，并且能够承受高压。这些发现表明，带套囊的ETT可以通过儿科LMA管腔，与无套囊的ETT不同，它可以提供无气体泄漏的通气。
