Comparison of the efficacy of nebulized magnesium sulphate versus dexamethasone in preventing post-operative sore throat following endotracheal intubation in patients undergoing laparoscopic surgeries- A double-blinded, randomized controlled trial

A total of 64 patients scheduled for elective laparoscopic abdominal surgeries under general anaesthesia will be included. Participants will be randomly allocated into two groups based on 1:1 allocation ratio using block randomization technique. Web-based block generation will be done through https://sealedenvelope.com/ and used for patient allocation into:

·       Group A: Patients receiving nebulized magnesium sulphate.

·       Group B: Patients receiving nebulized dexamethasone.

  The size of the block will be decided by a staff member and kept blinded from the investigator in a separate sealed document to avoid selection bias. Patient’s allocation will be kept concealed in a separate sealed envelope and revealed after measurement of the baseline values and before the procedure.

 Group A will receive magnesium sulphate (50% W/V 2mL) with 3mL normal saline for nebulization 30 minutes before induction of anaesthesia in the preoperative receiving room.

Group B will receive dexamethasone 8 mg (2mL) with 3mL normal saline for nebulization 30 minutes before induction of anaesthesia in the preoperative receiving room.

 Both medications will be administered via mask nebulization approximately 30 minutes before induction of anaesthesia. The nebulization will be performed by a nurse unaware of group allocation, ensuring blinding. All intubations will be performed by qualified anaesthesiologists.

 All patients will be premedicated with tablet pantoprazole 40mg and alprazolam 0.5mg night before the surgery. All patients will be kept nil per oral overnight.

 After receiving nebulization in the receiving area, patient will be shifted to OT. All ASA standard monitors like HR, NIBP, SpO2, EtCO2 will be attached. Baseline vitals will be recorded. Patient will be preoxygenated for 4 minutes with 8L O2. Patient will be premedicated with Inj. Glycopyrrolate 0.01mg/kg IV, sedated with Inj. Midazolam 0.02mg/kg IV. Inj. Xylocaine 1.5mg/kg IV and Inj. Fentanyl 2mcg/kg IV will be given. Patient will be induced with Inj. Propofol 2mg/kg IV. Muscle relaxation with non-depolarizing muscle relaxant Inj. Atracurium 0.5mg/kg IV will be done. Using an appropriate size polyvinylchloride (PVC) endotracheal tube, patient will be intubated as smooth direct laryngoscopy by an experienced anaesthesiologist. ET tube will be fixed after 5-point auscultation and confirming bilateral air entry. Immediately after intubation, cuff pressure will be measured and monitored every 60 minutes, ensuring cuff pressure is maintained less than 30cm H2O.

  Adequate depth of anaesthesia will be achieved. Depth of anaesthesia will be maintained with 33% O2, 66% N2O and 1 MAC sevoflurane. Haemodynamics of the patient will be monitored every 15 minutes intraoperatively. 20 minutes before the procedure, Inj. Ondansetron 4mg IV will be given to prevent post-operative nausea and vomiting. After gentle adequate oral suctioning with soft tip suction catheter, patient’s breathing efforts will be noted. Neuromuscular blockade reversal with Inj. Neostigmine 0.05mg/kg IV and Inj. Glycopyrrolate 0.01mg/kg IV will be given. Smooth extubation will be done when the patient is fully awake.

 Patients will be assessed in the post-operative ward by a nursing staff blinded for the study. Incidence of sore throat, pain, discomfort and other related symptoms will be assessed after shifting the patients to post-operative ward at 0-hour, 4-hour, 8-hour, 12-hour and 24-hour according to the POST severity grading score. Total incidence of POST will be calculated by the ratio of number of patients who experienced sore throat at least once to the total number of patients. The patients will be then followed-up to monitor any other post-operative complications and such findings will be recorded.