摘要:Background Compared to an equivalent sized polyvinyl chloride (PVC) double-lumen tube (DLT), a silicone DLT has a shorter endobronchial segment. The aim of this study was to compare the incidence of clinically significant displacement of left-sided PVC and silicone DLTs after a positional change to a lateral position from a supine position and determine its effect on the need for DLT repositioning for successful lung separation in patients undergoing thoracic surgery. Methods One hundred eight adult patients requiring one-lung ventilation were randomly divided into group P (PVC DLT, n = 54) and group S (Silicone DLT, n = 54). The position of the DLT was observed before and after lateral positioning to assess the effect of the position change. The incidence of clinically significant displacement (>10 mm) of DLT was compared between the groups. Results DLTs were clinically significantly displaced in group P (17/48, 35.4%) and group S (18/52, 34.6%) after lateral positioning (p = 0.933). A proximal displacement (31.3% [group P] and 25.0% [group S]) was more common than distal displacement (4.2% [group P] and 9.6% [group S]), with no significant intergroup difference (p = 0.494). After lateral positioning, critical malposition of DLT with bronchial herniation to the right main bronchus was 8.3% (group P) and 7.9% (group S, p = 0.906). Conclusion Left-sided PVC and silicone DLTs produced comparable incidences of clinically significant displacement and, consequently, required similar rates of repositioning for successful lung separation after lateral positioning.