Comparison of oral Pregabalin with Clonidine for attenuating pressor response to direct Laryngoscopy in patients undergoing thyroidectomy-A randomised controlled trial

Direct laryngoscopy and tracheal intubation are employed as gold standard for conduct of safe general anaesthesia for thyroidectomy  surgeries. But both these procedures are noxious stimuli leading to hemodynamic fluctuations , higher myocardial oxygen demend , increased catecholamines and cardiac arrythmias. This is a concern in all patients particularly in cardiac and cerebrovascular diseases. Several techniques are employed to prevent the hemodynamic responses following laryngoscopy and intubation such as deepening the plain of anesthesia,use of vasodilators, lignocaine, betablockers calcium channel blockers and opiods. All these agents have various side effects.if no specific measures are taken , heart rate can increase from 26 to 66 percentage depending on the method of intubation and systemic blood pressure can increase from 36 to 45 percentage which maybe due to variation in balance between sympathetic and parasympathetic outflow or receptor hypersensitivity. Clonidine posses several properties to make it a valuable premedicant to attenuate the hemodynamic response of laryngoscopy and tracheal intubation. Pregabalin is a voltage gated calcium channel inhibitor with analgesic , anxiolytic and anticonvulsant properties making it a useful oral premedicant. Hence,we are conducting the present double blinded , randomised controlled trial to evaluate the effectiveness of oral pregabalin to clonidine in attenuating hemodynamic changes during direct laryngoscopy and tracheal intubation.

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