[Correct placement of left-sided double lumen endotracheal tubes: a simple verification technique]

Double lumen endotracheal tubes (DLTs) are used in thoracic surgery for selective bronchial intubation, which is required for single lung ventilation. Correct placement of the tube is checked by means of fiberoptic bronchoscopy. We present a simple alternative method to help confirm the correct placement of left-sided DLTs. The method consists of passing a suction catheter through the tracheal lumen of the tube. Our hypothesis was that if the catheter can be inserted without difficulty, the tube is correctly placed. The objective was to determine the sensitivity and specificity of that criterion.

We studied patients scheduled for elective left pneumonectomy or lobectomy. After passing the catheter through the left-sided DLT, placement was checked by means of fiberoptic bronchoscopy (gold standard) and the results were compared with the placement assessment based on ease of insertion.

One hundred patients were included. The DLT was judged to be correctly placed in 88% of patients in whom the catheter was inserted without resistance. Bronchoscopy corroborated this finding in 84% of cases; the tube was found to be incorrectly placed in the remaining 4% of cases and had to be reinserted. Resistance was noted in 12% of cases and bronchoscopy confirmed that the tube was incorrectly placed in those patients.

This technique can be very useful in placing left-sided DLTs in situations where fiberoptic bronchoscopy is not available and if the anesthesiologist has a thorough command of the method. Our results support the routine use of this criterion as it is simple and easy to learn. It should be remembered, however, that confirmation of placement by means of fiberoptic bronchoscopy is currently the gold standard technique.