Difficulty in inserting left double-lumen endobronchial tubes at the cricoid level in small-statured women: A retrospective study

BACKGROUND AND AIMS Left double-lumen endobronchial tube (DLT) sizes are selected using tracheal diameters and left mainstem bronchial diameters (LMBDs) determined from chest radiographs or computed tomography (CT) scans. In Western women, 35-Fr or 37-Fr DLTs are often selected. However, difficulties can be encountered when inserting 32-Fr or 35-Fr DLTs in Japanese women. We investigated success rates for 32-Fr or 35-Fr DLT insertion in Japanese women and determined the causes of unsuccessful DLT insertion. METHODS We searched anaesthesia records of Japanese women aged ≥20 years who underwent thoracic surgery with 32-Fr or 35-Fr DLTs between April 2010 and March 2015 in our hospital. In the successful group (SG), patients were intubated using the initially selected DLTs. By contrast, in the unsuccessful group (UG), the DLT size had to be changed. The Mann-Whitney U-test and Fisher's exact test were used to compare groups. RESULTS The SG included 149 (96.1%) of 155 cases of 32-Fr DLT use and 119 (95.2%) of 125 cases of 35-Fr DLT use. Patient height was significantly lower in the UG than in the SG for the 35-Fr DLT (P = 0.0036). In seven of 12 UG patients (three for 32-Fr and four for 35-Fr), the transverse diameters of cricoid cartilages were smaller than the DLTs' tracheal diameters, thereby preventing passage through the cricoid cartilages. CONCLUSION Along with LMBDs, transverse diameters of cricoid cartilages based on CT scans or ultrasonogram findings may help in selecting the appropriate left DLT size.