Hypotension after induction of general anesthesia and before surgical stimulation is a prevalent anesthesia-related side effect. The post-induction hypotension disrupts organ perfusion and may cause organ damage particularly acute kidney injury, cerebrovascular stroke, and myocardial ischemia. Post-induction hypotension occurs with greater frequency and severity in the elderly. This is because of aged-related diminished cardiac reserve and impaired autonomic homeostasis. Pleth variability index (PVI) is a software program that measures the dynamic changes of the PI that occurs during a complete respiratory cycle. Our primary outcome is to determine the predictive ability and the optimal cut-off value of pre-anesthesia PVI for predicting elderly patients who are at risk of developing post-induction hypotension

Inclusion Criteria:

• patients with ASA physical status I or II
• patients will receive general anesthesia

Exclusion Criteria:

• Patients with a history of cardiorespiratory disorders
• patients with uncontrolled hypertension or cardiac dysrhythmias
• Patients with renal or hepatic diseases.
• Patients with long-standing diabetes and peripheral vascular diseases.

all patients. Patients ≥ 65 years, ASA physical status I or II, and scheduled for elective surgery under general anesthesia will be enrolled in the study.