Feasibility of MDCT for Predicting Left Double Lumen Endotracheal Tube Displacement during Supine to Lateral Repositioning of Patients

Abstract

Multidetector-row computed tomography (MDCT) allows visualization and measurement of anatomical structures. Because we seek a reliable method by which we can predict displacement of the double lumen endotracheal tube (DLT) in patients when supine to lateral repositioning is required during surgery, we performed MDCT preoperatively for 84 patients scheduled for elective respiratory surgery with a left DLT. We obtained 3D MDCT reconstruction images of each patient's bronchus and then measured the distance between the vocal cords and the bifurcation of the left upper lobe bronchus. We defined this distance as the MDCT-derived appropriate depth of placement (ADP). We used two other methods to determine ADP: the standard measurement method based on the patient's height and the chest X-ray method based on the distance from the superior border of the sixth cervical vertebra to the tracheal bifurcation. During surgery, we evaluated the actual change in ADP when the patient was moved from the supine to the lateral position. We then compared the actual ADP with the MDCT-derived ADP to assess whether the MDCT-derived ADP predicts DLT displacement during the patient repositioning.We found that during surgery, the DLT had slipped out of position in 31 (44%) patients, had moved too deeply in 6 (7%), and had not changed in 41 (49%). Multiple logistic regression analysis showed that the MDCT-derived ADP was significantly associated with DLT displacement upon patient repositioning (odds ratio, 2.9; 95% CI, 1.5-5.6; p=0.002), whereas standard ADP and chest X-ray-derived ADP were not associated with DLT displacement. We postulate that various factors, such as extension or flexion of the neck and size of the DLT, may contribute the DLT displacement during patient repositioning.We believe, on the basis of our study data, that ADP derived from pre-operative MDCT will be useful for predicting DLT displacement when patients are moved from the supine to lateral position during surgery.