The aim of this observational study is to investigate the potential effects of metformin on postoperative nausea and vomiting (PONV) in patients undergoing surgery under general anesthesia. The primary research question is:
Does preoperative metformin exposure influence the incidence or severity of PONV in patients undergoing general anesthesia? Patients who are already prescribed metformin as part of their routine medical management will be compared with those not taking metformin. Data on PONV occurrence, severity, and recovery outcomes will be collected through structured postoperative surveys administered after surgery.
Voluntarily sign the informed consent form;
Age ≥ 18 years;
Patients who require surgical treatment under endotracheal intubation with general anesthesia as determined by the treating physician.
Emergency surgery;
Currently taking medications with established antiemetic effects (e.g., corticosteroids, antipsychotics) due to underlying medical conditions;
Cognitive impairment or psychiatric disorders that preclude cooperation with questionnaire assessments;
Anticipated inability to extubate the tracheal tube postoperatively, which would interfere with outcome assessment;