Comparison of Haemodynamic Effects of Clonidine and Dexmedetomidine for Intubation using Intubating Laryngeal Mask Airway in Patients undergoing Elective Surgery under General Anaesthesia: A Randomised Clinical Study

Introduction: The Intubating Laryngeal Mask Airway (LMA) is a Supraglottic Airway (SGA) device through which endotracheal intubation can be performed. Laryngoscopy and intubation are known to initiate a haemodynamic response. LMAs in general produce a lesser pressor response, but intubating LMA provokes a higher response due to the invasiveness of tracheal intubation. Aim: To compare dexmedetomidine and clonidine in attenuating the haemodynamic response to intubating LMA, Ramsay sedation score, and the incidence of laryngopharyngeal injury. Materials and Methods: A randomised clinical study was conducted in the Department of Anaesthesiology, Sikkim Manipal Institute of Medical Sciences, Gangtok, Sikkim, India, over a period of one year spanning from June 2020 to May 2021 to compare the two drugs in patients with American Soceity of Anaesthesiology (ASA)-I. The doses of clonidine and dexmedetomidine were 2.5 mcg/kg and 0.5 mcg/kg, respectively. The study parameters {Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Blood Pressure (MBP), Peripheral Saturation of Oxygen (SpO2) were recorded at baseline, pre- and post -induction, and at various time intervals (0, 1, 3, 5 minutes) after intubation. Sedation score was also recorded before intubation and after extubation. Statistical Packages of Social Sciences (SPSS) version 23.0 was used to analyse the data (chi 2 test for categorical variables and analysis of variance for continuous data). Results: There was no statistically significant difference between the two groups for the duration of surgery (p=0.267), duration of anaesthesia (p=0.197), and the duration between closure and extubation (p=0.407). Dexmedetomidine better attenuated the response of HR and SBP just before induction, post -induction, and immediately post-intubation. All the haemodynamic parameters were better controlled by dexmedetomidine immediately after intubation. Sedation was better with dexmedetomidine in the pre-intubation as well as post-extubation period, except at five minutes post -drug infusion when clonidine was better. Conclusion: Compared to clonidine, dexmedetomidine was more effective in attenuating the patient's haemodynamic response to intubating LMA in the immediate peri-intubation period. However, from 1 minute post-intubation onward, both drugs behaved similarly in controlling the pressor response.