Preoperative ketamine nebulization attenuates the incidence and severity of postoperative sore throat: A randomized controlled clinical trial.

Background: Endotracheal intubation is the prominent cause of airway mucosal injury which results in postoperative sore throat (POST), with an incidence of 21%-65%. Although this complication is minor, if left unresolved, it produces significant agony and annoyance to the patient. This study was conducted to evaluate the efficacy of nebulized ketamine in decreasing POST.

Materials and Methods: After written informed consent, 96 patients of the American Society of Anesthesiologists physical status (PS) 1-2 between 18 and 60 years, of either sex undergoing general anesthesia (GA) with tracheal intubation were enrolled in this prospective, randomized, placebo-control, and double-blind controlled trial. Patients were randomized into two groups; Group 1 received ketamine 50 mg (1.0 ml) with 4.0 ml of saline nebulization, while Group 2 received saline nebulization 5.0 ml for 15 min. GA was administered 15 min after completing nebulization. On reaching postanesthesia care unit, POST monitoring was done at 0, 2, 4, 6, 12, and 24 h after extubation. POST was graded on a four-point scale (0-3).

Results: The overall incidence of POST in this study was 25%: POST was experienced by 7 patients (14.6%) in ketamine and 17 patients (35.4%) in saline group (Fisher's exact P = 0.018). There was statistically significant reduction in the incidence of POST in ketamine group when compared to saline, at 2, 4, 6,12, and 24 h postoperatively ( P < 0.05*). Severity of sore throat was also higher in saline group when compared to ketamine at 4 h ( P = 0.030*) and 6 h ( P = 0.016*) postextubation.

Conclusion: Preoperative ketamine nebulization effectively reduced the incidence and severity of POST, with no adverse effects.