Evaluating The Efficacy Of Nebulised Dexmedetomidine Vs Clonidine to Attenuate Hemodynamic Response During Laryngoscopy and Tracheal Intubation Under General Anaesthesia-A Prospective Randomised double blinded clinical study

Patients will be randomly assigned to one of two groups (A and B) using computer-generated random numbers. Group A will receive nebulisation with dexmedetomidine 2 mcg/kg in 4 ml of 0.9% normal saline. Group B will receive nebulisation with clonidine 2 mcg/kg in 4 ml of 0.9% normal saline. A qualified anaesthesiologist with 1 year of experience, uninvolved in the study, will prepare the study drugs. Allocation will be concealed using a sequential numbering system with sealed opaque envelopes, which will be opened in the pre-operative room. After allocation, baseline systolic, diastolic, and mean blood pressure, heart rate, and peripheral oxygen saturation (SpO2) will be recorded in the pre-anaesthetic room. Monitoring will continue throughout the nebulisation procedure, and vital signs will be recorded. Nebulisation will be performed using a wall-attached oxygen drive source 20 minutes before induction until the chamber empties. Any side effects like bradycardia (defined as heart rate less than 25 % of the baseline or <50/min) and hypotension (defined as systolic blood pressure less than 25 % of the baseline or <90 mm Hg) will be recorded during and after the nebulisation.

Patients will be transferred to the operating room, where standard ASA monitors will be attached. Following preoxygenation with 100% oxygen, fentanyl 2 mcg/kg will be administered intravenously. Anaesthesia will be induced with propofol titrated to loss of verbal response. Atracurium 0.5 mg/kg will be used for muscle relaxation. Direct laryngoscopy and endotracheal intubation will be performed using an appropriately sized laryngoscope and endotracheal tube. Intubation will be performed by a qualified anaesthesiologist with one year of experience. Cormack-Lehmann (CL) grading of laryngoscopy and duration of intubation will be recorded. Controlled ventilation will then be established and titrated to maintain end-tidal carbon dioxide at 30-40 mmHg. Systolic, diastolic, and mean blood pressure, heart rate, and SpO2 will be recorded during intubation and at 1, 3, 5, 8, 11, and 15-minutes post-intubation. If blood pressure increases by more than 25% from baseline, or if heart rate increases by more than 25% from baseline, esmolol 0.5 mg/kg will be administered intravenously to attenuate the hemodynamic response. Depth of anaesthesia will be maintained with sevoflurane to a minimal alveolar concentration (MAC) of 1. Intraoperative analgesics, fluids, blood products and vasopressors will be administered at the discretion of the consultant anaesthesiologist. Thirty minutes before the end of surgery, ondansetron 0.1 mg/kg will be administered intravenously. All patients will be reversed with neostigmine 0.05 mg/kg and glycopyrrolate 0.02mg/kg and extubated after meeting extubation criteria.