Effect of Preoperative Oral Carbohydrate on Hypotension After Anesthesia Induction in Elderly Patients With Joint Replacement

Inclusion Criteria: 1. Patients undergoing elective unilateral joint replacement (total hip or knee) 2. ASAⅠ-Ⅲ Exclusion Criteria: 1. Diagnosed patients at high risk of reflux aspiration (diabetes mellitus, obesity (BMI\>30), gastrointestinal obstruction, elevated intracranial pressure, and esophageal disease) 2. Eating disorders 3. History of gastrointestinal or epigastric surgery 4. Recent use of drugs that affect gastrointestinal motility 5. Heart disease (severe arrhythmias, severe heart valve disease, heart failure, unstable angina on the day of surgery) 6. Severe poorly controlled hypertension (MAP≥135 mmHg) or hypotension (MAP≤55 mmHg) before induction 7. Difficult airway 8. Severe hepatic and renal insufficiency