Department of Anesthesiology and Pain Medicine, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea.
Br J Anaesth. 2013 Sep;111(3):496-504. doi: 10.1093/bja/aet152. Epub 2013 May 13.
Current tracheal tubes (TTs) cannot guarantee a perfect seal against pulmonary aspiration of upper airway secretions. The purpose of this study was to investigate whether a gel layer between the tracheal tube with double cuffs (Double cuffs) prevents fluid leakage past TT cuffs.
In vitro fluid leakage tests were performed using the Double cuff with or without a gel layer between the two cuffs and four commercially available TTs (Euromedical Standard TT, Mallinckrodt Hi-Lo™, Microcuff, and Mallinckrodt TaperGuard™) when placed in artificial tracheas with three-different internal diameters (ID; 16, 20, and 22 mm). Blue-dyed water (5 ml) was placed above the cuff, and the extent of fluid leakage was observed for 48 h. Each test was repeated five times with new tubes at six different intracuff pressures (15, 20, 25, 30, 40, and 50 cm H2O).
In all of the conventional TTs and the Double cuff without a gel layer, fluid leakage was observed even at clinically acceptable intracuff pressures (25-30 cm H2O). However, in the Double cuff with a gel layer, no fluid leakage was observed for 48 h at all intracuff pressures in three-different sized artificial tracheas. At an intracuff pressure of 20 cm H2O in a 20 mm ID trachea, the average volume of injected gel was 2.0 ml. After removal of the TT, the mean volume of the remaining gel in the trachea was 0.10 ml.
A prototype TT with gel-layered Double cuffs completely blocked fluid leakage past the cuffs for 48 h in a bench-top model. Clinical studies are required to determine whether this TT reduces the risk of ventilator-associated pneumonia.
目前的气管导管（TT）不能保证对呼吸道分泌物的完全密封，防止上呼吸道分泌物吸入肺部。本研究旨在探讨气管导管双层套囊（Double cuffs）之间的凝胶层是否能防止 TT 套囊周围的液体泄漏。
在体外使用有或无双层套囊之间凝胶层的 Double cuffs 和四种市售 TT（Euromedical Standard TT、Mallinckrodt Hi-Lo™、Microcuff 和 Mallinckrodt TaperGuard™）进行液体泄漏测试，将 TT 置于三种不同内径（ID；16、20 和 22 mm）的人工气管中。在套囊上方注入 5 ml 蓝色染液，观察 48 h 内液体泄漏情况。每种测试在六个不同的套囊内压（15、20、25、30、40 和 50 cm H2O）下用新的 TT 重复五次。
在所有常规 TT 和无凝胶层的 Double cuffs 中，即使在临床可接受的套囊内压（25-30 cm H2O）下，也观察到了液体泄漏。然而，在双层套囊加凝胶层的情况下，在三种不同大小的人工气管中，在所有套囊内压下 48 h 均未观察到液体泄漏。在 20 mm ID 气管中套囊内压为 20 cm H2O 时，注入凝胶的平均体积为 2.0 ml。TT 取出后，气管中残留凝胶的平均体积为 0.10 ml。
在台面上的模型中，具有凝胶层双层套囊的 TT 原型完全阻止了套囊周围 48 h 的液体泄漏。需要进行临床研究以确定这种 TT 是否能降低呼吸机相关性肺炎的风险。
