The Effect of Intra-Articular Meperidine and Bupivacaine 0.5% on Postoperative Pain of Arthroscopic Knee Surgery; a Randomized Double Blind Clinical Trial

Arthroscopic knee surgeries have a painful postoperative course, which often necessitates acute pain management. Among different analgesia techniques, Intra-articular injection is the technique of choice for many pain specialists, based on its confined effect to the surgical site (knee), lack of systemic effects and promotion of safe early ambulation.The aim of this study was to compare analgesic effects of intra-articular meperidine, bupivacaine 0.5% or their combination after knee arthroscopic surgery.Sixty ASA class I-II patients' candidates for arthroscopy knee surgery enrolled in a randomized double blind study to receive either 20 mL of bupivacaine 0.5%; 100 mg meperidine (diluted in normal saline) or bupivacaine 0.5% along with 100 mg meperidine. A written informed consent was obtained from all patients. Postoperative analgesia duration, VAS at 2, 6, 12 and 24 hours, the first analgesic request time, total fentanyl consumption in first 24 hours, patients' satisfaction and adverse effects were recorded.The bupivacaine-meperidine group had better duration of postoperative analgesia (P = 0.001), latter first analgesic request (P ≤ 0.001), lower total fentanyl consumption in first 24 hours after the operation (P = 0.001), less mean VAS at 2 hours (P = 0.001) and more patients' overall satisfaction (P = 0.01) compared with each medication alone. VAS at 6, 12 and 24 postoperative hours were not different between the groups of study. No adverse effects were observed.Although postoperative intra-articular meperidine is a better alternative for bupivacaine, their combination could improve their analgesic effects compared with each other alone.