Overview

This study investigated the effect of Trendelenburg position on preventing post-induction hypotension in elderly patients undergoing abdominal surgery with general anesthesia. The patients will receive the 10° Trendelenburg position or supine position during anesthesia induction. The primary outcome is the area under a mean arterial pressure (MAP) below 65 mm Hg within the first 15 minutes during anesthesia induction.

Eligibility

Inclusion Criteria:

• patients aged 65-90 years
• scheduled for abdominal surgery with general anesthesia
• expected to have continuous radial arterial pressure monitoring
• American Society of Anesthesiologists (ASA) physical status I to III

Exclusion Criteria:

• contraindications or failure of radial arterial catheterization
• expected possible difficult airway
• non-sinus rhythm
• increased intracranial pressure
• patients at high risk of regurgitation or aspiration
• inability to provide consent