Evaluation of Methadone’s Role in Attenuating Hemodynamic Stress Response During Laryngoscopy and Endotracheal Intubation: A Single Group Interventional Study

The patients will be first assessed in the pre-anesthesia clinic (via history taking, through clinical examination, and routine investigations. The ratio of pain intensity will be recorded in response to the question, rate your worst pain using an 11-point numeric rating scale (NRS) (where 0 indicates no pain and 10 indicates worst pain). The study protocol will be explained to the patient and informed written consent will be obtained and patient would be allowed to ask doubts regarding the study and can withdraw from the study at any point of time. Standard institute guidelines will be followed for fasting and premedication. All the patients will be shifted to a preoperative area 1 hour before operation time. After cross-checking the patient details, confirming the compliance of the preoperative order the patient will be shifted into the operation theater. standard monitoring will be done and baseline heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), oxygen saturation and ECG and modified Ramsay sedation score will be recorded and monitored. An 18G IV infusion line will start, and all patients will be hydrated with approximately 6-8 m/kg of normal saline before induction.

All patients will be oxygenated with 100% oxygen for 3 min & INJ Methadone 0.3mg/kg (over 1 min) & wait for 3-5min, Propofol 1% solution, 1.5 mg/kg body weight (over 1 min) intravenously will be given. After ensuring induction and check ventilation, Vecuronium bromide 0.1 mg/kg body weight would be administered. The patient will be ventilated for 4 min and Endotracheal intubation will be done with cuffed endotracheal tube by an experienced anesthesiologist with 3 years of experience. After confirming for bilateral equal air entry, the endotracheal tube will be fixed and normocapnic ventilation will start with sevoflurane maintenance in a titrating way.EtCO2 monitoring & hemodynamic parameters (HR, BP, MAP, SPO2, ECG) will be recorded at the below mentioned time. T2-Pre intubation

T3- 1 min after intubation

T4 -3 min after intubation

T5- 5 min after intubation

T6- 7 min after intubation

T7- 10 min after intubation

After that, during the perioperative period BP, HR, MAP, ETCO2 & SPO2 will be monitored at 5 min intervals. Additional dose of skeletal muscle relaxant i.e., vecuronium bromide and rescue analgesia Inj paracetamol 1gm will be given. Inj ondansetron will be given 30 min before the end of surgery. During the surgery, any adverse event like

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bradycardia, tachycardia or arrhythmia would be recorded. Bradycardia will be treated with inj atropine 0.6 mg & hypotension with normal saline & mephenteramine.

At the end of the surgery, neuromuscular blockade will be reversed by inj neostigmine 50mcg/kg and inj glycopyrrolate 10mcg/kg. Extubation will be performed following standard extubation criteria recovery. post-operatively pain will be assessed using NUMERICAL RATING SCALE at the following periods: pre-operatively and 1, 2, 6, 12, and 24 hours postoperatively. If patients’ pain score is 4 or higher then they will receive Inj PCM 1 gm twice to thrice daily. Postoperative sedation score will be evaluated by Modified Ramsay Sedation Scale