Hannallah M S, Gharagozloo F, Gomes M N, Chase G A
Department of Anesthesiology, Georgetown University Medical Center, Washington, District of Columbia 20007, USA.
Anesth Analg. 1998 Nov;87(5):1027-31. doi: 10.1097/00000539-199811000-00008.
A double-lumen endobronchial tube (DLT) bronchial cuff inflation technique that reliably ensures effective water-tight isolation of the two lungs has not been determined. In this study, 20 patients undergoing thoracic surgery requiring a left DLT had the bronchial cuff of the DLT inflated by one of two techniques. In Group 1, the cuff was inflated to produce an air-tight seal of the left bronchus using the underwater seal technique. In Group 2, the cuff was inflated to a pressure of 25 cm H2O. After bronchial cuff inflation in both groups, water-tight bronchial seal was tested by instilling 2 mL of 0.01% methylene blue (MB) above the bronchial cuff of the DLT. Fifteen minutes later, fiberoptic bronchoscopy was performed via the bronchial lumen of the DLT to determine whether MB had seeped past the bronchial cuff. Cuff volume was 0.75+/-0.64 and 0.76+/-0.46 mL, cuff pressure was 30.1+/-27.0 and 25.0+/-0.0 cm H2O (mean+/-SD), and MB was positively identified in two and five patients in Groups 1 and 2, respectively. The difference in cuff volume and pressure and the higher MB seepage in Group 2 compared with Group 1 was not statistically significant. In both groups, MB seepage occurred only when the bronchial cuff volume was <1 mL and when the patients were positioned in the left lateral decubitus position. These findings suggest that the risk of aspiration is greatest when the DLT is positioned in the dependent lung and when the bronchial cuff volume is <1 mL.
Water-tight sealing of the left bronchus by DLT bronchial cuff was tested after cuff inflation using two different techniques. Neither air-tight bronchial seal nor cuff pressure of 25 cm H2O guaranteed protection against aspiration. The risk of aspiration was greatest when the DLT was positioned in the dependent lung and when the bronchial cuff volume was < 1 mL.
尚未确定一种能可靠确保两肺有效水密隔离的双腔支气管导管（DLT）支气管套囊充气技术。在本研究中，20例接受胸外科手术且需要左DLT的患者，其DLT的支气管套囊通过两种技术之一进行充气。在第1组中，使用水封技术将套囊充气以产生左支气管的气密密封。在第2组中，将套囊充气至25 cm H₂O的压力。两组支气管套囊充气后，通过在DLT支气管套囊上方注入2 mL 0.01%亚甲蓝（MB）来测试水密支气管密封。15分钟后，通过DLT的支气管腔进行纤维支气管镜检查，以确定MB是否已渗漏过支气管套囊。套囊容积分别为0.75±0.64和0.76±0.46 mL，套囊压力分别为30.1±27.0和25.0±0.0 cm H₂O（均值±标准差），第1组和第2组分别有2例和5例患者MB检测呈阳性。与第1组相比，第2组套囊容积和压力的差异以及更高的MB渗漏率无统计学意义。在两组中，仅当支气管套囊容积<1 mL且患者处于左侧卧位时才发生MB渗漏。这些发现表明，当DLT位于下垂肺且支气管套囊容积<1 mL时，误吸风险最大。
使用两种不同技术对DLT支气管套囊充气后，测试其对左支气管的水密密封情况。支气管气密密封和25 cm H₂O的套囊压力均不能保证防止误吸。当DLT位于下垂肺且支气管套囊容积<1 mL时，误吸风险最大。
