Preventive Effect of Preoperative Administration of Hange-Shashin-To on Postoperative Sore Throat: A Prospective, Double-Blind, Randomized Trial.

OBJECTIVES: The present study aimed to determine the efficacy of Hange-Shashin-To (HST), a Kampo medicine, in treating postoperative sore throat and nausea.

DESIGN: This randomized, controlled, double-blind study was conducted among two groups of adult female patients who were scheduled to undergo benign laparoscopic surgery under general anesthesia. All patients in each group had a physical status of either 1 (normal, healthy patient) or 2 (patient with a mild systemic disease), according to the American Society of Anesthesiologists. Patients were randomly assigned to either the HST group or the placebo (control) group.

INTERVENTION: Before surgery, the HST group received HST (5.0 g) mixed with jelly, while the placebo group received only jelly. Patients and the evaluator were blinded to the treatment status.

OUTCOME MEASURES: At 0, 3, and 24 hours after anesthesia recovery, an investigator (also blinded to the treatment status) recorded incidence and severity using the Numeric Rating Scale for sore throat and nausea.

RESULTS: Incidence and severity of sore throat were significantly lower in the HST group than in the control group immediately and 3 hours after surgery (p<0.05). In contrast, incidence and severity of nausea did not differ significantly between the HST and control groups.

CONCLUSIONS: HST administration before general anesthesia did not alleviate postoperative nausea, but effectively decreased the incidence and severity of postoperative sore throat in female patients undergoing laparoscopic surgery.