PURPOSE: Double-lumen tube (DLT) is commonly used for lung isolation. The bronchial cuff of DLT must achieve a water-tight seal to protect the lung from spoiling. The seal characteristics of endotracheal cuff depend on its material and shape, and a cuff made of polyvinyl chloride(PVC) cannot provide complete sealing during endotracheal intubation. The endobronchial cuffs of most modern disposable DLTs are made of PVC and thus the sealing characteristics can be a cause for concern. Thus, we performed an in vitro study to investigate the sealing characteristics of PVC- DLT.
METHODS: Two different sized PVC-DLTs (BronchoCath TM, Mallinckrodt) were investigated. Based on the previous reports, artificial bronchus was simulated with a 11 mm and 12 mm cylinder, and 35 F and 37 F DLTs were tested for each. The artificial bronchus was intubated with the endobronchial portion of DLT. The endobronchial cuff was inflated to 25, 50 and 75 cmH2O cuff pressure (Group 25, 50 and 75, respectively) and 5 ml of fluid was applied above the endobronchial cuff. Fluid leaking past the endobronchial cuff was measured for 60 mins. Time to first detection of leakage, and time to each ml of fluid leakage were compared between the groups by using Kruskal-Wallis test or Mann-Whitney test.
RESULTS: Five DLTs were used for each test. All cuffs showed leakage past the cuff. The time to first detection of fluid leakage was significantly longer in Group75, without any difference between the other groups (1.3±0.2,2.0±0.3, and 3.5±0.6 min). The time spent for the whole test fluid to leak was also longer in Group75, but not different between the others (13.9±2.8,14.3±2.1 and 33.4±9.5 min; group 75,50 and 25, respectively).
CONCLUSIONS: Our study shows that PVC endobronchial cuff cannot provide tight seal with a intracuff pressure of 25 cm H2O, the maximal allowable pressure to avoid ischemic mucosal damage. Even a cuff pressure 75 cmH2O neither provided complete seal
CLINICAL IMPLICATIONS: A different material, such as polyurethane might be considered as a material for endobronchial cuff.
DISCLOSURE: The following authors have nothing to disclose: Sunghee Han, Hyungchul Lee, Jinhee Kim, Jinyoung Hwang
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