Comparative Effectiveness of the C-MAC Video Laryngoscope Versus Direct Laryngoscopy in the Setting of the Predicted Difficult Airway

Background: Video laryngoscopy may be useful in the setting of the difficult airway, but it remains unclear if intubation success is improved in routine difficult airway management. This study compared success rates for tracheal intubation with the C-MAC® video laryngoscope (Karl Storz, Tuttlingen, Germany) with conventional direct laryngoscopy in patients with predicted difficult airway.

Methods: We conducted a two arm, single-blinded randomized controlled trial that involved 300 patients. Inclusion required at least one of four predictors of difficult intubation. The primary outcome was successful tracheal intubation on first attempt.

Results: The use of video laryngoscopy resulted in more successful intubations on first attempt (138/149; 93%) as compared with direct laryngoscopy (124/147; 84%), P = 0.026. Cormack-Lehane laryngeal view was graded I or II in 139/149 of C-MAC attempts versus 119/147 in direct laryngoscopy attempts (P < 0.01). Laryngoscopy time averaged 46 s (95% CI, 40-51) for the C-MAC group and was shorter in the direct laryngoscopy group, 33 s (95% CI, 29-36), P < 0.001. The use of a gum-elastic bougie and/or external laryngeal manipulation were required less often in the C-MAC intubations (24%, 33/138) compared with direct laryngoscopy (37%, 46/124, P = 0.020). The incidence of complications was not significantly different between the C-MAC (20%, 27/138) versus direct laryngoscopy (13%, 16/124, P = 0.146).

Conclusion: A diverse group of anesthesia providers achieved a higher intubation success rate on first attempt with the C-MAC in a broad range of patients with predictors of difficult intubation. C-MAC laryngoscopy seems to be a useful technique for the initial approach to a potentially difficult airway.