Prospective Trial to Compare Direct and Indirect Laryngoscopy Using C-MAC PMD with Macintosh Blade and D-BladeD in a Simulated Difficult Airway

Objective. Evaluation of C-MAC PM in combination with a standard Macintosh blade size 3 in direct and indirect laryngoscopy and D-Blade in indirect laryngoscopy in a simulated difcult airway. Primary outcome was defned as the best view of the glottic structures. Secondary endpoints were subjective evaluation and assessment of the intubation process. Methods. Prospective monocentric, observational study on 48 adult patients without predictors for difcult laryngoscopy/tracheal intubation undergoing orthopedic surgery. Every participant preoperatively received a cervical collar to simulate a difcult airway. Direct and indirect laryngoscopy w/o the BURP maneuver with a standard Macintosh blade and indirect laryngoscopy w/o the BURP maneuver using D-Blade were performed to evaluate if blade geometry and the BURP maneuver improve the glottic view as measured by the Cormack-Lehane score. Results. Using a C-MAC PM laryngoscope, D-Blade yielded improved glottic views compared with the Macintosh blade used with either the direct or indirect technique. Changing from direct laryngoscopy using a Macintosh blade to indirect videolaryngoscopy using C-MAC PM with D-Blade improved the Cormack-Lehane score from IIb, III, or IV to I or II in 31 cases. Conclusion. Te combination of C-MAC PM and D-Blade signifcantly enhances the view of the glottis compared to direct laryngoscopy with a Macintosh blade in patients with a simulated difcult airway. Trial Registration Number. Tis trial is registered under number NCT03403946.