Respiration; Sleep Disorder

This single-center, stratified randomized double-blind trial tests tegileridine, a new pain drug, for pain relief after weight-loss surgery. Researchers will compare tegileridine with standard opioid pain medicine. Eligible patients having bariatric surgery will be randomly assigned to one of the two treatment groups. Patients and study teams will not know which treatment each participant receives. Participants will be grouped based on whether they have obstructive sleep apnea (OSA). The primary measurement is postoperative recovery quality in the first 24 hours after surgery using the QoR-15 survey. The study will also track pain scores, rescue pain medication use, and drug side effects for 7 days after surgery. There is no guaranteed benefit for participants. Study pain medicines may cause side effects. Doctors will provide rescue treatment for uncontrolled pain.