Given the importance of correct positioning of the double-lumen endotracheal tube in one-lung ventilation, the results of a Taiwanese study may have significant implications for patients undergoing the procedure. Researchers there found that use of a wireless, malleable video stylet results in a greater first-time success rate and decreased intubation times than the traditional method of blind intubation confirmed by fiber-optic bronchoscopy.
“Traditionally, the double-lumen endotracheal tube is intubated into the trachea and then rotated 90 degrees counterclockwise to advance slowly and blindly until resistance is met,” said Ping-Tang Chen, MD, a staff anesthesiologist at National Taiwan University Hospital, in Taipei City. “However, malposition is one of the most concerning problems. The Disposcope is a new wireless, malleable video stylet; our goal was to investigate its efficacy with real-time double-lumen placement.”
The researchers enrolled 54 patients into the trial, all of whom were undergoing double-lumen tube placement. Patients were anesthetized according to standard institutional protocol. Vocal cords were visualized using a laryngoscope, and the tube was intubated into the trachea.
Blind Versus Guided
As Dr. Chen reported at the 2016 annual meeting of the American Society of Anesthesiologists (abstract A1099), patients in the control group had the tube advanced blindly to its final position. By comparison, those in the Disposcope-assisted group saw the tip of the stylet placed in the opening of the tube and the image displayed wirelessly on a screen. The tube was then advanced under real-time image guidance.
Auscultation was performed in all patients, and the fiber-optic bronchoscope was inserted to confirm tube position. The researchers compared the first-attempt success rates, time to successful intubation, the incidence of incorrect positioning, the number of adjustment attempts and the number of times needed to adjust tube position. Anesthesia-related parameters, such as pre- and postintubation heart rate, blood pressure and oxygen saturation, were comparable between groups.
It was found that two of the 27 patients in the control group had the tube inserted into the right main bronchus. The tubes were then withdrawn to the midtrachea and reinserted under standard fiber-optic guidance. By comparison, all patients in the experimental group had the tube inserted to the left main bronchus under real-time guidance.
Although the majority of double-lumen tubes in controls were inserted too deeply during fiber-optic bronchoscope confirmation and needed to be withdrawn to the final position, 24 of those in the Disposcope group were inserted to the final position without the need for adjustment.
“We also found that the total procedure time [155.0 vs. 130.6 seconds] and total intubation time [21.5 vs. 18.5 seconds] were both less in the Disposcope group,” Dr. Chen explained. Laryngoscopy time, on the other hand, was comparable between groups (7.5 vs. 7.2 seconds), as was tracheal intubation time (11.8 vs. 10.5 seconds). Perhaps not surprisingly, auscultation time was longer in patients undergoing traditional intubation (15.2 vs. 12.8 seconds), as was the time required to confirm and adjust tube placement (15.6 vs. 7.3 seconds).
Devices such as this, the investigators concluded, ultimately may prove useful in providing real-time double-lumen tube insertion, thereby obviating the need for both acoustic and fiber-optic bronchoscope confirmation of correct endobronchial tube position.
“So now we have changed the way we practice in chest surgery,” Dr. Chen noted. “We use real-time insertion by using this video stylet. And we found this is a powerful and effective way for us to place the endotracheal tube into the correct position.”
Session co-moderator Uday Jain, MD, PhD, staff anesthesiologist at Alameda Health System, in Oakland, Calif., was quick to point out the availability of alternative approaches. “Let’s also remember that there are double-lumen endotracheal tubes with a camera chip built into the tip,” Dr. Jain noted. “Also, in many institutions two providers are used for double-lumen tube insertion, one slowly advancing the tube and the other observing through the fiber-optic bronchoscope inside the tube.”