Effect of intravenous dexmedetomidine on haemodynamic responses to laryngoscopy, tracheal intubation and anaesthetic and analgesic requirements: a randomized double-blind clinical efficacy study

Background: Dexmedetomidine is an alpha 2-adrenergic receptor agonist that provides sedation, anxiolysis, hypnosis, analgesia, and sympatholysis. The present study is aimed to assess the efficacy of dexmedetomidine in attenuating sympathoadrenal response to laryngoscopy and tracheal intubation and to analyse its effect on intraoperative anaesthetic and analgesic requirements. Methods:?Sixty?patients?were?randomized?to?receive?either?dexmedetomidine?1?g/kg?(Group?D)?or?10?mL?of?0.9% saline (Group S) over 10 minutes before induction of anaesthesia and after standard induction procedure the same study drug infusions were continued. Blood pressure, heart rate (HR) and Ramsay sedation score (RSS) were monitored at fixed time interval after study drug infusion and anaesthesia induction. Results: After study drug administration the changes in HR and blood pressure was statistically significant between the groups (p = <0.001) at all-time intervals during study period. There was 50% reduction in thiopentone requirements in Group D in comparison to Group S (p<0.001). The intraoperative additional dose of morphine requirement was less in Group D in comparison to Group S to maintain the steady haemodynamics (p<0.001). Statistically significant difference was noticed in Group D regarding RSS at 5 min and 10 min after study drug infusion (p=0.025 and p=0.001 respectively) and again at 30 min after extubation (p= 0.002) when compared with Group S. Conclusions: Our observations suggest that dexmedetomidine was effective in attenuating the heart rate and blood pressure rise during laryngoscopy and intubation, and decrease the thiopentone and morphine requirements intraoperatively.