Comparison of Intravenous Esmolol and Oral Clonidine for Attenuation of Stress Response to Laryngoscopy and Intubation in Patients Undergoing Surgery under General Anesthesia: A Randomized Clinical Study

Abstract

Introduction: Direct laryngoscopy and endotracheal intubation are the most noxious stimuli during induction of anaesthesia. Airway instrumentation frequently induces a cardiovascular stress response characterized by hypertension and tachycardia due to reflex sympathoadrenal discharge caused by epipharyngeal and parapharyngeal stimulation. Various pharmacological approaches have been used to attenuate the pressure responses to laryngoscopy and tracheal intubation e.g. volatile inhalational agents, lignocaine, opioids, sodium nitroprusside, nitroglycerine, calcium channel blockers, and adrenergic blockers (alpha -2 agonists and beta blockers).Objectives: The purpose of this study is to compare the efficacy and safety of i.v esmolol and oral clonidine in attenuating the changes of blood pressure and heart rate by tracheal intubation.Materials and Methods: 40 patients posted for various surgeries under general anesthesia were randomly divided into two groups. Group C subjects received Clonidine 150 mcg PO, 90 minutes prior to induction of anaesthesia where as Group E subjects received I.V Esmolol 0.5mg/kg 90 seconds prior to intubation. To maintain blinding, Group C patients received I.V 0.9% Normal saline 90 seconds prior to intubation where as Group E patients received placebo tablet containing multi vitamins 90 minutes prior to induction .HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), Mean arterial pressure (MAP) , rate pressure product (RPP), Spo2, ECG will be recorded prior to induction (Base line), at the time of intubation and 1, 3, 5, and 10 min after intubation . Type of study: A randomized clinical study.Results: Pulse rate, SBP, DBP, MAP and RPP were comparable at baseline, at time of induction, during laryngoscopy and intubation and throughout whole study period it was not statistically significant in both groups (p>0.05). However in Intergroup comparison, SBP was comparable at base line and after 5 min of laryngoscopy and intubation in both groups, but SBP was significantly higher after 1 and 3 min of laryngoscopy and intubation in Group E than Group C. Also, there was statistically significant increase in MAP following laryngoscopy and intubation at one min in Group E than Group C (P<0.05). RPP was significantly higher after 1 and 3 min of laryngoscopy and intubation in Group E than Group C. Postoperative complications like dryness of mouth, excessive sedation, PONV, hypotension, Bradycardia, bronchospasm were not observed in any case in both groups. Conclusion: This study concluded that clonidine and esmolol provide hemodynamic stability but clonidine provides more stability with postoperative sedation.