Randomized Controlled Trial Comparing Nebulised Magnesium Sulphate and Ropivacaine on Endotracheal Intubation Response and Postoperative Sore Throat in Patients Undergoing General Anaesthesia

Background: Post-operative sore throat (POST) is a frequent complication of endotracheal intubation during general anesthesia, and affects patient comfort and recovery. Preoperative nebulization with topical medications and pharmacological prophylaxis are widely studied methods to attenuate airway irritation and hemodynamic responses, and to reduce POST.
Aim: To compare the efficacy of preoperative nebulisation with magnesium sulphate (MgSO4) and Ropivacaine in reducing the incidence and severity of POST, haemodynamic response during intubation and extubation, and associated symptoms including cough and hoarseness.
Methodology:  In our prospective randomised clinical study, 70 patients with ASA grades I-II aged 18 to 65 undergoing elective surgery under general anaesthesia requiring endotracheal intubation were included. Patients were randomised to two groups (n=35 each): Group M patients received nebulised magnesium sulphate (250 mg in 5mL), and Group R patients received nebulised ropivacaine (0.25%, 5 mL), 12.5 mg, 20 minutes before induction. The haemodynamic parameters, POST score, cough, voice hoarseness, and complications were evaluated at several time points up to 24 hours after surgery.
Results: The ropivacaine group maintained better haemodynamic stability than the magnesium sulphate group, as shown by lower mean HR, SBP, DBP, and MAP during intubation, intraoperatively, and at extubation (p<0.05).   The ropivacaine group had significantly lower rates of cough severity, hoarseness, and sore throat (p<0.05). No difference was observed in the duration of laryngoscopy, number of intubation attempts, or other complications.
Conclusion: Pre-operative nebulisation with ropivacaine (0.25%, 5 mL), 12.5 mg, is more effective than magnesium sulphate in reducing POST, airway-related symptoms, and haemodynamic response.