RESUMO
Backgroud: In one-lung ventilation using the left-sided double-lumen tube (LDLT), it is important to place the LDLT in correct position to maintain adequate ventilation. We investigated the frequency of and the factors affecting the LDLT malposition in endotracheal intubation. Methods: Ninety one (55 male and 36 female) patients were observed. After endotracheal intubation, using 35 and 37 Fr. sized Robertshaw type LDLT, auscultation and fiberoptic bronchoscope were performed to make sure the correct position of LDLT. The heights, weights, age, and sex were noted. The lengths and diameters of trachea, and the angles and diameters of both bronchi on chest x-ray were measured for comparison. Results: Normal in auscultation and gross malposition were 87.9% and 12.1%. Among those normal in auscultation, normal in bronchoscope, advancing and removing fine malposition were 66.2%, 18.8% and 15.0%, respectively. The angle of left bronchus is 37.71+/-4.60degrees in normal in ausculation and 37.71+/-4.60degrees in gross malposition. The length of trachea is 13.41+/-0.90 cm in normal in bronchoscope, 14.49+/-0.78 cm in advancing fine malposition and 11.86+/-0.35 cm in removing fine malposition. The patient's height is 167.27+/-7.12 cm in normal in brochoscope, 172.45+/-6.67 cm in advancing fine malposition and 163.12+/-6.54 cm in removing fine malposition. Conclusions: The angle of left bronchus is a factor affecting gross malposition. And the length of trachea and the patient's height are factors affecting fine malposition. Thus it is necessary to obtain in advance information on patient's height, length of trachea and angle of left bronchus on chest x-ray, to reduce the occurrence of the LDLT malposition.