The distance between the carina and the distal margin of the right upper lobe orifice measured by computerised tomography as a guide to right-sided double-lumen endobronchial tube use.

Our hypothesis was that the incidence of malposition of a right-sided double-lumen endobronchial tube and right upper lobe collapse may increase when the distance between the carina and the distal margin of the right upper lobe orifice is less than 23 mm, measured from a computerised tomography scan. A total of 76 patients undergoing left-sided thoracic surgery were enrolled. Patients with a measured distance of <23 mm (n=38) were compared with age-, sex- and body mass index-matched patients with a distance≥23 mm (n=38). Right-sided double-lumen endobronchial tubes were used universally. We monitored endobronchial tube malposition and incidence of right upper lobe collapse throughout surgery. There was a significantly higher incidence of bronchial cuff herniation in patients with a distance<23 mm in both the supine position and the lateral decubitus position (p<0.001). The incidence of intra-operative malposition in the <23 mm group was also significantly higher than in the ≥23 mm group (31 (82%) vs 8 (21%), respectively, p<0.001). Right upper lobe collapse was detected postoperatively in five patients (13%) in the distance<23 mm group, compared to none in the ≥23 mm group. We recommend that the distance between the carina and the distal margin of the right upper lobe bronchus should be routinely measured on the pre-operative computerised tomography scan, and if it is <23 mm, consideration should be given to using a left-sided endobronchial double-lumen tube in preference to a right-sided one.