Oral Clonidine vs Oral Gabapentin for Obtunding Hemodynamic Response to Laryngoscopy and Tracheal Intubation

Introduction: The sequence of induction of anaesthesia, laryngoscopy and tracheal intubation are highly noxious stimuli associated with marked haemodynamic changes consisting of increase in circulating catecholamines and autonomic reflex activity which involves activation of adrenocortical system. There is an increase in myocardial oxygen demand and dysrhythmias may occur as well.These changes are transient in nature and do not affect healthy individuals however in patients with co morbidities like hypertension, raised intracranial pressure or coronary artery disease. The cardiovascular response is also directly related to the force and duration of laryngoscopy. Both Clonidine, an ?2 adrenergic agonist and gabapentin which is a GABA-B receptors agonist causes obtunding of hemodynamic response during laryngoscopy and endotracheal intubation. Aim: The aim of conducting this study was to compare the effects of 100mcg oral Clonidine given 90 min prior to time of surgery with 300mg oral gabapentin given 90 min before surgery in blunting the haemodynamic response to laryngoscopy and intubation. Methodology: A prospective randomized study was done in 60 patients undergoing elective surgeries general anaesthesia in Meenakshi medical college hospital and research institute was selected randomly and the patients were randomly split into two groups of 30 each. One group C received 100mcg of orral clonidine and the other group G received 300 mg of Gabapentin orally 90 minutes before surgery. ECG monitoring, systolic blood pressure, diastolic blood pressure, mean arterial pressure(MAP) with noninvasive monitoring and pulse oximetry (SpO2) and ETCO2 monitoring was done and recorded after premedication, after induction, before and during intubation at different time intervals (T0, T1, T3, T5 T10 and T15 minutes). Other adverse effects of this oral premedication with 100mcg Clonidine and 300mg Gabapentin like bradycardia, hypotension, sedation and dryness of mouth were recorded post operatively also. Result: In both group the heart rate (HR), systolic blood pressure (SBP),diastolic blood pressure (DBP),mean arterial pressure (MAP) were increased atT0,T1,T3,T5 and T15.The 1 minute post induction values of SBP, DBP, MAP were significantly less in Clonidine group (Pless than0.001) and significance persisted upto 5 minutes. Increase in HR was less in Clonidine group than in the Gabapentin group. Conclusion: Premedication with oral Clonidine 100mcg 90 minutes before laryngoscopy and intubation superior to oral gabapentin 300mg in obtunding the hemodynamic response to endotracheal intubation and laryngoscopy.