Dexmedetomidine versus Clonidine for Improved Quality of Emergence from General Anaesthesia: A Randomised Placebo-Controlled Study

Introduction: Extubation of the trachea upon emergence from General Anaesthesia (GA) is often accompanied by potentially dangerous events, like coughing, hypertension, tachycardia, and agitation. The centrally acting a -2 agonist, dexmedetomidine, has been evaluated to attenuate the emergence/extubation response. However, there is insufficient evidence regarding the effectiveness of clonidine for the same purpose. Aim: This study aimed to evaluate the quality of emergence from GA in patients receiving clonidine infusion versus dexmedetomidine infusion. Materials and Methods: In this randomised, double-blinded trial conducted over a period of 5 months, 105 patients aged 18-70 years, of either sex, with American Society of Anaesthesiologists (ASA) grade I-III, scheduled for elective laparotomies with an estimated duration of 1-4 hours, were randomly assigned to groups D, C, and P. Group D received inj. dexmedetomidine 1 μg/kg, group C received clonidine 3 μg/kg, and group P received placebo (normal saline) via intravenous (i.v.) route over 10 minutes using a syringe pump, 10 minutes prior to the anticipated end of surgery. Haemodynamic parameters, cough, agitation, shivering, time to extubation, sedation, Visual Analogue Score (VAS), and Postoperative Nausea and Vomiting (PONV) scores were recorded before, during, and after extubation. The incidence of complications (hypotension, bradycardia, or others) was also recorded. Categorical data were expressed as proportions, while numerical data were presented as mean±Standard Deviation (SD) or median±Interquartile Range (IQR). Appropriate data were compared using Statistical Package for Social Sciences (SPSS) version 16.0. Results: A total of 105 patients were included, with 53 males and 52 females. There was no difference in the demographic characteristics, such as age, gender, and Body Mass Index (BMI), amongst the three groups. Haemodynamic parameters (Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP)) were significantly lower in patients of group D and group C compared to the placebo group at 5, 10, 10, and 15 minutes, respectively, after the beginning of drug infusion (p-value <0.05). Patients in groups D and C had significantly lower median cough scores at 20-25 minutes compared to the placebo group (p-value at 20 and 25 minutes was 0.012 and <0.001, respectively). There was a significant reduction in postoperative pain, as measured by VAS score, and an increase in sedation, as measured by Ramsay sedation score, in groups D and C compared to the placebo group. There was no statistical difference in agitation score, shivering score, PONV score, time to extubation, and incidence of complications among the three groups (p-value >0.05). Conclusion: Administration of 1 μg/kg of dexmedetomidine or 3 μg/kg of clonidine over 10 minutes prior to recovery from General Endotracheal Tube Anaesthesia (GETA) results in a better quality of recovery, as evidenced by a statistically significant reduction in cough scores in patients undergoing elective laparotomies when compared to patients of placebo group.