Intra-articular buprenorphine after knee arthroscopy. A randomised, prospective, double-blind study.

Abstract

Demonstration of peripheral opioid receptors in inflamed synovia supports the concept of peripheral opioid analgesia. The aim of this study was to evaluate the analgesic effect of intra-articular administration of buprenorphine after knee arthroscopy. In a double-blind randomised trial, 48 patients were assigned to four groups: group A patients received buprenorphine 100 micrograms i.a. and NaCl 0.9% i.m., group B patients received bupivacaine 0.25% 50 mg i.a. and NaCl 0.9% i.m., group C patients received NaCl 0.9% i.a. and buprenorphine 100 micrograms i.m., and group D patients received NaCl 0.9% i.a. and NaCl 0.9% i.m. Intensity of postoperative pain was evaluated by VAS at recovery (T0) and 1, 3, 6, 12, 24 h after operation (T1, T2, T3, T4, T5), at rest and during passive 10 degrees knee flexion. Total analgesic requirements and side effects related to study drugs were recorded. The VAS scores were significantly higher in groups C and D than in group A and B patients. The differences were significant at T0, T1, T2 and T3. At T1, group C and D patients had greater analgesic requirement than groups A and B. No patients developed side effects. Intra-articular buprenorphine and i.a. bupivacaine, both produced equally good postoperative pain control and allowed a significant reduction of analgesic requirement after knee arthroscopy.