Oral Endotracheal Intubation with Restricted Glottis View using C-MAC D Blade®: A Randomised Controlled Trial

Introduction: The perspective of airway management has undergone a considerable transformation since the advent of Video Laryngoscopes (VL). VL has rapidly been accepted as an intubation tool in a variety of clinical scenarios. This heralds a wide array of VL models with their own strengths and weaknesses. The C-MAC D blade (R) is one such VL with an angulated blade that provides an excellent glottis view, but negotiating the Endotracheal Tube (ETT) past the glottis opening and into the trachea might be difficult. No study till date was done on the C-MAC D blade (R) with different glottis views for intubation. Aim: To compare the Total Time of Intubation (TTI) with restricted glottis view and full glottis view with C-MAC D blade (R) as the primary aim, along with the first attempt intubation rate and complications during intubation. Materials and Methods: The present prospective single-centre randomised controlled trial was conducted in the Department of Anaesthesiology, Shree Krishna Hospital, PSMC, Karamsad, Gujarat, India, from September 2021 to August 2022. A total of 42 patients were randomly divided into two groups: group-F (n=21), which had a full glottis view, and group-R (n=21), which had a restricted glottis view. Randomised glottis views were achieved with the C-MAC D blade (R) VL during oral endotracheal intubation in both groups. Video recordings of the intubations were made, and TTI, first attempt success rate and complications during intubation were noted. Statistical analysis was done with an independent sample t-test to compare the two groups of continuous variables using STATA version 14.2. Results: The mean age in group-F was 45.86 +/- 10.83 years and in group-R was 47.76 +/- 9.14 years. The male-to-female ratio in group-F was 10:11 and in group-R was 9:12. Overall, the first- attempt successful intubation rate with the C-MAC D blade (R) in both groups was 90.48%. However, it was higher in group-R (95.24%) compared to group-F (85.71%). TTI was less in group-R compared to group-F (36.19 +/- 11.11 vs 45 +/- 15.89 seconds, p-value=0.0438). Group-R had lower incidence of postoperative sore throat (14.29% vs 57.14%, p-value=0.004) compared to group-F. Conclusion: Total time of intubation was less with a restricted glottis view compared to a full glottis view with C-MAC D blade (R) VL. Additionally, the restricted view had a higher first attempt intubation rate. Postoperative sore throat was significantly lower in the restricted view, with a lesser incidence of oropharyngeal trauma compared to the full glottis view.