Point-of-care ultrasound and auscultation versus fiberoptic bronchoscope in determining the position of double-lumen tube

Double lumen tube (DLT) is used in lung surgeries. Classically, the patient should undergo fiberoptic bronchoscopy (FOB) to confirm the location of the DLT and its proper function. However, the sensitivity of ultrasound and clinical methods in diagnosing the correct position of DLT has not yet been definitively determined. This study was designed to assess the accuracy of point-of-care ultrasound and auscultation versus Fiberoptic Bronchoscope in determining the position of the Double-Lumen Tube.

This cross-sectional study of diagnostic value measurement type was conducted on patients who were candidates for double lumen implantation. After induction of anesthesia, DLT with the appropriate size was implanted, and then the position of DLT was evaluated. In the first step, the lungs were examined by auscultation, then the ultrasound was performed, and two signs of lung pulse sign and lung sliding sign were examined as signs of normal lung and ventilated lung. FOB was performed by an anesthesiologist. At the end, by opening the chest after surgery, the surgeon's opinion about the quality of lung collapse was recorded.

In our study, the correct placement of the tube was correct in 37 cases and wrong in 3 cases, which were checked and corrected by FOB. Vital signs of the patients were stable before and during the operation. There were no problems with anesthesia during the surgery. Diagnostic sensitivity of lung auscultation clinical examination was 64.9% and chest ultrasound was 91.9%. The sensitivity of ultrasound compared to auscultation was not significant (P=0.242), but there was a clinically significant difference in the positive predictive value of the two, so that the positive predictive value of lung auscultation was 88.9% and lung ultrasound was 91.9%. In terms of surgeon satisfaction level, 22 cases (59.5%) had excellent satisfaction and 15 cases (40.5%) had moderate satisfaction. The sensitivity of ultrasound was not significant in comparison with the surgeon's satisfaction.

Ultrasound can be a good substitute for FOB. Although ultrasound cannot have all the functions of FOB, but having advantages such as lower cost, speed of operation, and non-invasiveness, makes it more practical than FOB.