Comparative Evaluation of King Vision Video Laryngoscope, McCoy and Macintosh Laryngoscopes in Patients Scheduled for Mucormycosis Surgery: A Randomised Clinical Trial

Abstract

Introduction: Mucormycosis, an aggressive fungal infection may result in a difficult airway owing to its inflammation. King Vision Video Laryngoscope (KVVL) is a useful addition to a difficult airway armamentarium. McCoy laryngoscope with hinged tip is well-known equipment of difficult airway cart. Conventional Macintosh laryngoscope dominates in anaesthesia practice. Standard, existing and contemporary devices were compared in difficult airways resulting from mucormycosis. Aim: To compare the relative performance of KVVL, McCoy, and Macintosh laryngoscopes based on the ease of intubation and haemodynamic response in patients with mucormycosis. Materials and Methods: The present study was a randomised clinical trial, conducted in a tertiary care government hospital, during June-August 2021 on 90 consenting patients of 18-65 years age, belonging to either sex with microbiologically confirmed mucormycosis undergoing debridement surgery. Group A was intubated with a non channeled KVVL, while group B had McCoy and group C had Macintosh laryngoscope. Primary outcome parameters were Cormack Lehane (CL) grade, time from laryngoscopy to successful intubation, number of attempts, any adjuncts or optimisation maneuvers, and any mucosal injury. Secondary outcome parameters were Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Blood Pressure (MBP) measured on arrival, before induction, after induction, and at 1, 2, 3, 5, and 7 minutes after intubation. Comparison of quantitative variables not normally distributed were analysed using Kruskal-Wallis test. Post-hoc analysis by Dunn’s multiple pairwise comparison test. Friedman test followed by pairwise comparison was done to compare haemodynamic parameters within each group. Chi-square test was used for qualitative variables. The p-value ≤0.05 was considered to be statistically significant. Results: The CL grade was lowest in group B (1.83±0.38) against group A (1.93±0.25), group C (2.13±0.35) with p-value of 0.029. Time from laryngoscopy to successful intubation was the least in group B (19.5±3.98 seconds) against group A (26.07±9.8 seconds), group C (21.33±3.74 seconds) with p-value of 0.002. No significant difference was there in the number of attempts, airway adjuncts/optimisation maneuvers, mucosal injury. Haemodynamic variables were comparable. Conclusion: McCoy laryngoscope was found to perform best in difficult airways resulting from mucormycosis. It was most effective for glottic visualisation, with the shortest time to successful intubation and, haemodynamic parameters were comparable to KVVL and macintosh laryngoscopes.

Keywords

• airway
• anaesthesia
• glottis
• haemodynamics
• intratracheal