INTRAVENOUS DEXAMETHASONE VERSUS LIGNOCAINE GEL FOR THE PROPHYLAXIS OF POST-OPERATIVE SORE THROAT IN PRONE POSITION SURGERIES

Abstract

Background: Post-operative sore throat is a frequent and distressing complication following endotracheal intubation under general anaesthesia. It is primarily caused by mechanical irritation and inflammation of the pharyngeal and laryngeal mucosa due to the endotracheal tube. Symptoms such as sore throat, hoarseness, and coughing may persist post-operatively, leading to increased patient discomfort, delayed recovery, and prolonged hospital stay. Several pharmacological methods have been employed for the prophylaxis of post-operative sore throat, including corticosteroids and local anaesthetics. Dexamethasone, a potent anti-inflammatory steroid, and lignocaine gel, a topical anaesthetic, are commonly used agents; however, evidence comparing their efficacy remains limited.

Methods: A randomised controlled trial was conducted at the Operation Theatre Complex, Mayo Hospital Lahore, from 1st August 2022 to 31st January 2023. Ninety adult patients aged 18 to 75 years, of either gender, scheduled for elective spine surgery under general anaesthesia were enrolled. Patients with upper respiratory tract infections, prior steroid use, neuromuscular disease, pre-existing sore throat, or multiple intubation attempts were excluded. Participants were randomly assigned to two equal groups (n=45) using the lottery method. Group A received 0.2 mg/kg intravenous dexamethasone prior to induction. Group B had 2% lignocaine gel applied to the endotracheal tube up to a length of 15 cm before intubation. Post-operative sore throat was assessed six hours following extubation in the post-anaesthesia care unit using a standardised questionnaire.

Results: The mean age of participants was 45.41 ± 12.93 years, with a male predominance (70%). The incidence of post-operative sore throat was significantly lower in the dexamethasone group (24.44%) compared to the lignocaine group (64.44%) with a p-value of 0.0001. Subgroup analysis revealed significantly higher rates of sore throat among older patients (p = 0.0003), females (p = 0.034), ASA II status (p = 0.002), and those with BMI >30 (p = 0.019). Across all stratified variables, patients receiving dexamethasone showed a consistent reduction in post-operative sore throat compared to those receiving lignocaine gel. Statistical analysis was performed using chi-square test and independent sample t-test, with significance set at p < 0.05.

Conclusion: Intravenous dexamethasone significantly reduces the incidence of post-operative sore throat when compared to lignocaine gel in patients undergoing intubation for elective spine surgery. Given its superior efficacy and consistent performance across patient subgroups, dexamethasone may be considered the preferred agent for prophylaxis against this common anaesthetic complication.