The effects of adding dexamethasone to intra-articular morphine injection on postoperative pain after knee arthroscopy

Background Postoperative analgesia after knee arthroscopy is mandatory for recovery and early rehabilitation. Medications were used intra-articularly to prolong postoperative analgesia and improve the quality of pain. The present study was scheduled to study the effects of dexamethasone addition to intra-articular morphine on postoperative pain after knee arthroscopy. Patients and methods This randomized double-blinded controlled study was carried out on 90 patients undergoing knee arthroscopy. The patients were randomly allocated into three equal groups. All medications were injected intra-articularly at the end of surgery. In the control group, the patients were administered 0.5% bupivacaine in normal saline. In M group, the patients were administered 5 mg morphine added to bupivacaine 0.5%. In MD group, the patients were administered 5 mg morphine and 8 mg dexamethasone added to bupivacaine 0.5%. Vital signs, visual analog score for pain at rest and movement, duration of analgesia, total analgesic consumption and adverse effects were recorded. Results MD Group showed lower visual analog score at rest and movement, prolonged postoperative analgesia, and decreased total analgesic consumption compared with the other groups (P<0.05). Conclusion The addition of dexamethasone to intra-articular morphine after knee arthroscopy prolongs the duration of analgesia, lowers pain scores, and decreases total analgesic consumption with minimal adverse effects.