Efficacy of Bonfils Fiberoptic Stylet for Difficult Tracheal  Intubation with Double Lumen Tube: A Prospective Observational Study

Background: The technique of choice to optimize one lung ventilation (OLV) consists in positioning a double lumen tube (DLT), limiting the use of bronchial blockers (BB) as a second option. The incidence of reported difficulties in positioning a DLT with direct laryngoscopy is higher compared to a single lumen tube. Consequently, alternative techniques enabling a successful DLT insertion after intubation failure with direct laryngoscopy should be considered as crucial rescue to optimize OLV.<br><br>Methods: The primary aim of this prospective observational single-center study was to report the successful rate of Bonfils rigid fiberscope as a rescue device for the placement of Double Lumen Tube (DLT) after intubation failure with direct laryngoscopy in patients undergoing elective Uniportal Video Assisted Thoracic Surgery (UVATS).&nbsp;The secondary endpoints were the identification of&nbsp;risk factors for difficult intubation with a DLT for either direct laryngoscopy and Bonfils rigid videostylet.403 patients&nbsp;≥ 18 year aged, ASA 1-3, scheduled for elective UVATS under general anesthesia&nbsp;were enrolled in the study, 223 males and 180 females, with a median age of 68 years (58-74 years), and BMI of 25.71 (22.76 - 29.06 kg* meter-2).&nbsp;Tracheal intubation with a left DLT was performed with direct laryngoscopy. In case of intubation failure, Bonfils rigid fiberscope was used as a rescue device for positioning DLT.<br><br>Results: Intubation failure with direct laryngoscopy occurred in 18 cases (4%). All of them were successfully intubated using Bonfils endoscope (successful rate 100%).&nbsp;40 patients (9,9%) required more than one attempt for positioning the DLT with Macintosh laryngoscope, while 8 cases (44%), intubated with Bonfils, required 2 attempts (p&lt;0.001).&nbsp;&nbsp;A median of 26 seconds (15-30 seconds) was required for intubation procedure using Macintosh blade laryngoscope and a median of 32.5 seconds (29.5-120 seconds) was registered for Bonfils rigid endoscope (p = 0.001).&nbsp;Multiple regression analysis showed an inverse relationship between the VAS operator perceived difficulty scale and the Mallampati score, as well as between the VAS scale and the interincisor distance.<br><br>Conclusion:&nbsp;Bonfils rigid endoscopic stylet showed to be a safe and efficient device for tracheal intubation with DLT in case of intubation failure with direct laryngoscopy.&nbsp;<br><br>Trial registration: ClinicalTrials.gov, ID: NCT03982745