Postprandial hypotension (PPH) and post-induction hypotension (PIH) are very common in the elderly population and are associated with a variety of poor outcomes.The purpose of this study is to investigate the correlation between PPH and perioperative adverse events such as PIH in the elderly.

With the deepening of the aging population in our country, the number of elderly patients undergoing surgery is also increasing. Elderly patients are at higher risk for hemodynamic instability due to organ dysfunction, decreased physiological reserve, and the coexistence of multiple chronic diseases.Postprandial hypotension (PPH) is common but often unrecognized among the elderly.PPH is defined as a fall in systolic blood pressure of >20 mm Hg, or a decrease to ≤90 mm Hg when preprandial systolic blood pressure is ≥100 mm Hg within 2 hours of a meal.The pathophysiology of PPH is not clear, the decreased cardiovascular autonomic function may play an important role. Post-induction hypotension (PIH) occurs after induction but before surgical incision and autonomic dysfunction is regarded as one of the major mechanisms.This study aims to prospectively explore the correlation between PPH and perioperative adverse events such as PIH in the elderly.

Inclusion Criteria:

1. Elderly patients (≥ 65 years old）;
2. Patients with American Society of Anesthesiologists(ASA) grade I-III;
3. Patients scheduled to undergo elective non-cardiac surgery under general anesthesia, with an anticipated surgical duration of over 1 hour；
4. Patients with intra-tracheal intubation following intravenous general ；anesthesia induction and maintenance；

Exclusion Criteria:

1. Patients with vascular diseases such as aortic aneurysm, aortic dissection, symptomatic atherosclerotic obliterans, Buerger's disease, and Raynaud's syndrome
2. Patients with secondary hypertension, including renal hypertension and endocrine hypertension.
3. Patients with chronic kidney disease requiring dietary restrictions or dialysis.
4. Patients with Parkinson's disease or other conditions causing tremors.
5. Patients with problems related to oral food ingestion or those requiring enteral nutrition.
6. Patients with difficulties in measuring the upper extremities or communication problems that would interfere with study procedures.
7. Patients unable to remain in a supine position for at least 2 hours.

Elderly patients scheduled for elective non-cardiac surgery under general anesthesia in Peking Union Medical College Hospital