The effect of intravenous low dose ketamine for reducing postoperative sore throat

BACKGROUND This study was performed to evaluate the effectiveness of intravenous low dose ketamine for reducing the incidence and severity of postoperative sore throat (POST). METHODS This was a prospective, randomized, double-blind clinical trial. The study population consisted of 70 patients between 20 and 70 years old who were classified as American Society of Anesthesiologists I-II and were scheduled for elective laparoscopic cholecystectomy. The patients were divided randomly into two groups. Patients in the ketamine group received an intravenous injection of 0.5 mg/kg of ketamine just before induction, followed by 10 microg/kg/min throughout the operation. Patients in the control group received intravenous saline instead of ketamine. The patients were interviewed 1, 6, and 24 h after the operation. The incidence and severity of POST were recorded. RESULTS No significant differences in the incidence and severity of POST during the 24 h after the operation were found between the two groups (21/31 in the ketamine group vs. 26/34 in the control group, P = 0.398). CONCLUSIONS Intravenous injection of low dose ketamine was not effective for reducing POST.