Intravenous Dexmedetomidine versus Intravenous Esmolol in Blunting the Laryngoscopy Response in Adult Normotensives Undergoing Elective Surgeries: A Randomised Clinical Trial
Authors: Jemmie Johns Rachel , Vidya MV , Sivakumar Segaran , Nagalakshmi P , Ranjan RV , Sagiev George Koshy 
Published: June 2022

Introduction: A wide array of drugs are available for blunting the laryngoscopy response. Amongst them both dexmedetomidine, and esmolol belong to the non-opioid group having least interference with the recovery process without causing significant respiratory depression, thus are suitable intervention for this purpose. Dexmedetomidine a sedative highly selective α2 adrenoceptor agonist and has an anaesthetic-sparing effect at induction. It suppresses the release of catecholamine in response to a noxious stimulant because of its central sympatholytic action. Esmolol with a different pharmacokinetic profile is a water soluble, cardio-selective, an ultrashort acting beta blocker has a short t1/2 thus suited for suppressing the transient pressor reflexes following acute noxious surgical or anesthesia stimuli. Aim: To compare the degree of attenuation of the laryngoscopy response following the use of single preinduction dose (Intravenous infusion at a dose of 1 µg/kg) of dexmedetomidine with that of esmolol (intravenous bolus at a dose of 0.5 mg/kg) in adult normotensives undergoing elective intubations. Materials and Methods: The randomised clinical trial was conducted in Pondicherry Institute of Medical Sciences from September 2016 to March 2018, on 60 patients of either sex, aged between 20-60 years with American Society of Anesthesiologists (ASA) physical status I or II requiring elective intubations for general surgical procedures. The patients were randomly divided into two groups (n=30 each). Prior to induction group A received 1 µg/kg dexmedetomidine IV infusion over 10 min, and group B received 100 mL IV infusion of normal saline over 10 min. Also 2 minute before laryngoscopy group A received 10 mL of normal saline (IV) bolus, whereas, group B received esmolol 0.5 mg/kg IV diluted in 10 mL of normal saline as a bolus. Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Mean Arterial Pressure (MAP) were recorded at baseline i.e, pre-procedure before the study drug infusion, preinduction, at laryngoscopy (0min) and 1,3,5 min after intubation. A rise of MAP and/or HR more than 20% from the baseline was considered as positive laryngoscopy response. Student’s unpaired t-test was used for analysis of inter group variables. Intra group variables were analysed using repeated measures Analysis Of Variance (ANOVA). Results: Mean age of patients in group A was 38.77±13.082 years and group B was 37.20±13.069 years (p-value=0.644). Results revealed that both the groups had an increase in HR and MAP at 1 minute after laryngoscopy and intubation. Mean readings of MAP showed a maximum rise of group A (2.15%) vs group B (7.25%) from the baseline readings at 1min following laryngoscopy which showed no statistical significance. The maximum HR increase following laryngoscopy was at 1 minute in group A (8.28%) vs group B (13.59%), which were below the positive laryngoscopy response. The mean HR, SBP, DBP and MAP recorded at preinduction, at laryngoscopy, 1, 3 and 5 mins following intubation showed no statistical difference (p-value >0.05) between the two groups. Conclusion: Usage of single dose preinduction dexmedetomidine iv infusion 1 µg/kg over 10 min was found to be equally effective in blunting the pressor response to laryngoscopy and intubation when compared to bolus dose of iv esmolol 0.5 mg/kg given 2 min prior to laryngoscopy.