Effects of Preoperative Gum Chewing on Sore Throat After General Anesthesia With a Supraglottic Airway Device: A Randomized Controlled Trial.

BACKGROUND: Postoperative sore throat (POST) is not uncommon after general anesthesia with a supraglottic airway (SGA) device. Although it was reported that some pharmacological and nonpharmacological measures can reduce POST, because of limitations and variable success rates, we need to find a simpler and more effective way to alleviate POST. METHODS: This prospective, observer-blinded, randomized controlled study enrolled 140 patients who required general anesthesia administered via a streamlined liner of the pharyngeal airway (SLIPA) for <60 minutes. They were randomly divided into the gum (group G, n = 70) and control (group C, n = 70) groups. Before the induction of general anesthesia for 5-10 minutes, the patients in group G chewed gum for 2 minutes. Group C was asked to swallow twice without any additional treatment. A standard anesthesia protocol was followed. The incidence and severity of sore throat were assessed up to 24 hours postoperatively. The primary outcome was the incidence of POST numerical rating scale (NRS) scores >3 within 24 hours after surgery, and the secondary outcomes included the POST (NRS) scores 2, 6, and 24 hours after the surgery. RESULTS: The incidence of moderate/severe POST (NRS >3) within 24 hours after surgery was significantly lower in group G (10.1%, 7/69) than in group C (40.6%, 28/69) (odds ratio 0.386, 95% confidence interval [CI], 0.153-0.976; P = .044). The median (interquartile range [range]) scores at 2, 6, and 24 hours after anesthesia in group G were lower than those in the control group at the same times (2 hours: 0 [0-3 0-4] vs 3 [0-3 0-6], P = .048; 6 hours: 0 [0-3 0-6] vs 2 [0-4 0-6], P = .048; 24 hours: 0 [0-1 0-7] vs 0 [0-2 0-6]; P = .011). There were 14 patients (20.3%, 14/69) in group G who had blood stains on the SGA device, which was significantly lower than the number in group C (37.7%, 26/69) (P = .024). In patients with bloody SGA devices, the incidence of POST scores >3 was significantly lower in group G (14.3%, 2/14) than in group C (73.1%, 19/26) (P < .001), while there was no significant difference between the 2 groups in the incidence of POST score >3 in patients without bloody SGA devices (group G: 9.1%, 5/55; group C: 20.9%, 9/43; P = .145). CONCLUSIONS: Chewing gum before surgery can effectively reduce POST with a SGA device for hysteroscopic surgery, especially in patients with pharyngeal mucosal injury.