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

Abstract

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 (χ2 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.

Keywords

• α-2 agonist
• endotracheal intubation
• supraglottic airways
• sympathetic response