The pre-emptive analgesic effect of intra-articular bupivacaine in arthroscopic knee surgery.

Abstract

The purpose of this study was to determine whether intra-articular injection of bupivacaine prior to surgery provided better pain control after arthroscopic meniscectomy as compared with post-operative administration of bupivacaine. Forty patients of American Society of Anesthesiologists (ASA) class I or II undergoing arthroscopic meniscectomy were assigned in a randomized, double-blinded manner into two groups: Group I received 20 ml of 2.5 mg/ml bupivacaine without epinephrine 30 min before skin incision and 20 ml of saline immediately after skin closure. Group II received identical injections in reverse order. All patients received total intravenous anesthesia. Post-operative pain scores were evaluated at 1, 2, 4, 6, 8, 12 and 24 h at rest and movement of the knee, using a 10-cm visual analog scale (VAS). The time to first analgesic use and 24-h analgesic consumption were recorded. Pain scores were lower in Group I compared with Group II at 1, 2, 4 and 6 h at rest and on movement (P < 0.05). The time to first analgesic use was longer in Group I, but there was no statistically significant difference in 24-h analgesic consumption. Intra-articular bupivacaine administered before surgery provided a statistically significant reduction in post-operative pain scores compared with post-operative bupivacaine administration.