Objective To explore the effect of preoperative chlorhexidine mouthwash on sore throat after hysteroscopy under general anesthesia of laryngeal mask airway.

Methods From November 2020 to March 2021, 110 cases of hysteroscopic operation under general anesthesia of laryngeal mask from Obstetrics and Gynaecology Hospital, Fudan University were performed. Patients were randomly divided into mouthwash group and control group, with 55 patients in each group. 5-10 min before induction of anesthesia, the patients were asked to gargle for 1-2 min or to swallow after two empty gargle without mouthwash. Anesthesia induction was performed with sufentanil, propofol and succinylcholine, and SLIPA laryngeal mask was placed. Anesthesia was maintained by continuous infusion of propofol. The incidence and severity of sore throat at 2 h, 6 h and 24 h after operation were observed.

Results The sore throat score in mouthwash group was significantly lower than that in control group at 24 h after surgery (P < 0.05). Sore throat score without blood on the laryngeal mask was lower in the two groups than in the patients with blood on the laryngeal mask at 2 h and 6 h (P < 0.05). The incidence of moderate/severe sore throat (NRS>3) within 24 h after surgery was significantly lower in the mouthwash group (9.43%) than in the control group (35.19%, P < 0.01). There was no difference in the incidence of blood stains on the laryngeal mask between the two groups. Among patients with blood on the laryngeal mask, the incidence of moderate/severe sore throat was significantly lower in the mouthwash group (11.76%) than that in the control group (56.52%) in 24 h after surgery (P < 0.01). The incidence of moderate/severe sore throat was significantly reduced in the mouthwash group(OR=0.258, P=0.02).

Conclusion Preoperative mouthwash application can effectively prevent the occurrence of postoperative moderate/severe sore throat in patients undergoing hysteroscopy under general anesthesia of laryngeal mask, especially reduce the incidence of postoperative moderate/severe sore throat in patients with injury of larynx.