Prevention of Rebound Pain After Orthopaedic Surgery With Peripheral Nerve Block (REBOUND)_part A

Rebound pain after peripheral nerve blocks reduces the benefits of regional anesthesia and increases opioid consumption. This rebound pain most likely results from suboptimal pain management, as patients receiving a peripheral nerve block are typically not given scheduled opioid doses. Oral Patient Controlled Analgesia (PCA) consists of an oral morphine prescription that allows patients to self-administer doses based on their pain score. This study will compare patients undergoing elective orthopaedic surgery under general anaesthesia or sedation with a peripheral nerve block, receiving oral morphine PCA either with or without additional scheduled oral morphine doses.