The study has not commenced due to medical staff strikes and staffing shortages.

Patients undergoing video-assisted thoracoscopic surgery requiring double-lumen tube intubation are randomized into two groups; gum group and control group. In the gum group, patients are instructed to chew gum for 2 minutes, approximately 10 minutes before induction of anesthesia. Patients in the control group are instructed to swallow saliva twice. Postoperative sore throat and hoarseness are assessed 30 minutes after recovery room admission, and at 2 and 24 hours after extubation.

Patients scheduled for video-assisted thoracoscopic surgery requiring double-lumen tube intubation and who agree to participate in the study are randomized to the gum chewing group and the control group. All clinical procedures are identical in both groups except for preoperative gum chewing. The gum chewing group chew gum for approximately 2 minutes, 10 minutes before induction of anesthesia. The control group do not chew gum and be induced to swallow saliva twice at the same time point. All patients are endotracheally intubated with a double-lumen tube using video laryngoscopy to provide unilateral pulmonary ventilation. Extubation is performed according to routine procedures, and the tube is assessed with whether there are blood stains at extubation. At 30 minutes in the recovery room and at 2 hours and 24 hours after extubation, the patient's sore throat is assessed for presence and intensity assessed by a 11-point numerical pain scale (minimal value 0 representing absence of pain, maximal value 10 representing the worst possible pain). Hoarseness at the same time points is also assessed for presence and severity. The presence of intubation-related complications (aspiration pneumonia) is assessed as a safety measure.

Inclusion Criteria:

• Patients aged 19-75 years undergoing routine video-assisted thoracoscopic surgery scheduled for double-lumen tube intubation
• Patients who are able to provide written informed consent to participate in the study and understand the procedures of this study
• American Society of Anesthesiologists physical status classification (ASA physical status classification) grade 1-2

Exclusion Criteria:

• Patients who have not consented to the study
• American Society of Anesthesiologists physical status classification (ASA physical status classification) grade 3-4
• Patients with poor dental health that limits chewing gum or tracheal intubation
• Patients who are expected to be difficult to intubate
• Patients with a history of aspiration pneumonia
• Patients being treated for chronic laryngitis, chronic bronchitis, asthma, reflux esophagitis
• Patients with a history of smoking within the past week
• Patients who have difficulty communicating or carrying out gum chewing and spitting instructions
• Patients with hypersensitivity to Xylitol gum ingredients
• Patients taking narcotic analgesics, antidepressants, and anticonvulsants for chronic pain
• Patients requiring endotracheal intubation or intensive care unit treatment after surgery
• Patients who, in the opinion of the investigator or study staff, are not appropriate candidates for this study