Effect of Different Oxygen Concentrations Before Extubation After General Anesthesia on Hypoxemia After Extubation in Post-anesthesia Care Unit

Exclusion Criteria

• •Respiratory infection recently, or atelectasis, inflammation, fibrosis, or pleural effusion by chest CT preoperatively.
• •History thoracic surgery and fractures of the sternum or ribs, chest deformity, difficulty in raising both upper limbs, or scoliosis.
• •High risk of reflux aspiration. Severe hepatic or renal dysfunction (e.g., Child-Pugh class C liver disease, or requiring dialysis).
• •Limb movement disorders. Mask ventilation or intubation difficulty during anesthesia induction. Occurrence of severe allergy, massive bleeding, suspected pulmonary embolism, pulmonary edema, myocardial injury, or cardiopulmonary arrest during surgery.
• •Currently participating in other clinical studies, which may have an impact on this study.
• •Inability to cooperate well for mental disorder, or hypophrenia.