Regional Nerve Block for Upper Extremity Surgery in Patients With Sarcopenia

The goal of this observational study is to learn about the impact of sarcopenia (muscle loss) on the efficacy of regional nerve blocks and postoperative recovery in patients undergoing upper extremity surgery. The main questions it aims to answer are: 1. Does sarcopenia affect the onset time and success rate of peripheral nerve blocks? 2. How does sarcopenia influence postoperative pain control and opioid consumption compared to patients receiving pure general anesthesia? Participants will undergo a preoperative muscle assessment, which includes a chair stand test and a brief ultrasound of the thigh muscle. Researchers will then observe and record their nerve block onset time (if applicable), postoperative pain scores, and recovery metrics during their hospital stay up to postoperative day 2.

Inclusion Criteria: * Age\>=50 years old * ASA I-III * Receiving upper limb surgery under general anesthesia Exclusion Criteria: * Severe cognitive impairment or inability to cooperate with pain and motor assessment * Pre-existing neuropathy of the musculocutaneous, median, radial or ulnar nerve * (for nerve block group) Contraindications to regional nerve blockade