A Comparative Study of King Vision Video Laryngoscopy and Macintosh Laryngoscopy in Routine Airway Management in Elective Surgeries - Cohort Study

Abstract Introduction: One of the most important anaesthesia skills is to secure the airway using an endotracheal tube. This is mostly done using a direct laryngoscope. The significant pressure response and inability to provide a satisfactory glottic view, has prompted the development of innovative intubation instruments. One such intubation tool is the video laryngoscope. Aims To assess and compare the application of Macintosh laryngoscopy (ML) and King Vision video laryngoscopy (KVVL) in adult patients scheduled for elective surgery while under general anaesthesia. Objectives The primary objectives - assess intubation time, CL (Cormack Lehane) grade, optimisation maneuvers required (bougie, cricoid Pressure) and hemodynamic changes. Secondary objectives- evaluating sore throat associated with intubation and laryngoscopy. Tertiary objective- distinction between KVVL and DL intubation techniques. Material and Method Study Design: Cohort study Study Period: The study was conducted between December 2022 and June 2024 - duration of eighteen months. Study Place: Patients who were planned for elective surgery under GA at Amala Hospital, over a period of one and half years. Hundred patients were assigned to undergo intubation using KVVL or ML according to week days (3days for VL, 3days for – DL). An experienced anaesthesiologist with at least 40 KVVL intubations performed each intubation. Sample Size: Total sample size 100 and divided into two groups. In ML group 50 and KVVL group 50. Study Population: Patients scheduled for elective surgery under GA. Sampling Method: Consecutive sampling method Method: Macintosh or King Vision intubation was assigned for one hundred elective surgery patients at Amala Institute of Medical Sciences. All of the data were collected and statistically analysed at the conclusion of the study. Results and conclusion In the two groups, there was no variation in the prevalence of gender, mean age, height, weight, or BMI. All 100 participants fell into Mallampatti classes I or II. Efficacy outcomes- The KVVL approach had a significantly longer mean time for scopy (45.56±20.15) than the ML method (23.32±11.08). In ML group, 31 (62.0%) participants were belonging to CL Grade I, 15 (62.0%) belongs to Grade II and 4 (8.0%) belongs to Grade III. Whereas in KVVL group, 47 (94.0%) were belongs to CL Grade I and 3 (6.0%) were Grade II and none in higher grades. The p-value indicated that the KVVL group had a greater laryngeal view than the ML group. Therefore, KVVL group had a better glottic visualization. Optimization maneuver was needed in 18 (36%) participants in ML group and only 2 (4%) in KVVL group. The KVVL group showed a significantly less mean change in SBP, DBP, MAP, and HR from baseline to PT0 (at the time of intubation), PT1 (1 minute after intubation), and PT3(3 minutes after intubation) than the ML group, suggesting more stable hemodynamic alterations. Post operative sore throat -Out of 50 cases in ML group, 5 (10.0%) had severe sore throat, 14 (28.0%) experienced moderate sore throat and 18 (36.0%)- mild sore throat. The KVVL group, none of them had severe sore throat, 8 (16.0%) had moderate and 22 (44.0%) had mild sore throat. The p-value indicated that the KVVL technique produced a considerably less severe sore throat than the ML technique.