COMPARISON OF HAEMODYNAMIC RESPONSE TO LARYNGOSCOPY WITH MACINTOSH AND MCCOY BLADES IN PATIENTS UNDERGOING GENERAL ANAESTHESIA

Abstract

Background: Non-pharmacological approaches for controlling laryngoscopy induced stress responses are less explored; resulting in under-diffusion of laryngoscopy blades with safe designs in the hospital system. The aim of this study was to evaluate comparative efficacy of McCoy blades and MacIntosh blades in reducing stress response to laryngoscopy.

Materials and Methods: Total Sixty adult patients with American Society of Anaesthesiologists’s (ASA) grade I or II were included with random assignment to group A (MacIntosh, n=30) and group B (McCoy, n=30). Primary study endpoints were changes in mean arterial pressure and heart rate in peri-induction phase during laryngoscopy and secondary endpoint was occurrence of adverse event or any in both groups. For continuous variables presented in mean ± standard deviation (SD), student’s t-test and for categorical variables chi-square test was performed with p <0.05 as significance criteria.

Results: The maximum change observed in mean arterial pressure (MAP) in the MacIntosh group was 28.08% compared to 15.25% in the McCoy group (p = 0.0001).The maximum rise in the heart rate (HR) compared to baseline seen was 25.67 % in the MacIntosh group compared to 14.86% in the McCoy group (p= 0.0001). No ST elevation, arrhythmia or any other side-effects were observed in any of the groups.

Conclusion: Given better clinical outcome with more attenuation of laryngoscopy induced stress response compared to conventional blades, McCoy blade could be advocated for robust diffusion and institutional use for ensuring patient safety especially in those with compromised cardiovascular dynamics.