Preoperative application of piroxicam gel compared to a local anaesthetic field block for postoperative analgesia

Abstract

The non-steroidal anti-inflammatory drugs inhibit prostaglandin synthesis and hence have an analgesic action. Following topical administration, the drug is concentrated in the tissues and so can have a local analgesic effect. This study investigated the effect of the preoperative application of topical piroxicam on postoperative analgesic requirement compared to a placebo group and a conventional local anaesthetic field block. Forty-two patients presenting for in-patient inguinal hernia repair were randomly allocated on a double-blind basis to have either piroxicam gel 15gm applied preoperatively, or an inguinal field block with 20 ml of 0.375% bupivacaine following induction of anaesthesia, or no treatment. Postoperative Visual Analogue Scores for pain on moving in group P, I or C on admission at 1h, 2h, and 4 h following surgery were: 2 vs 1 vs 6.5; 3 vs 3 vs 5; 3 v 2 vs 4.5; 3 vs 2 vs 5.0, respectively (P < 0.005). Median(range) time to first analgesia was 25.4(15-70) min in group I, 30.3(10-49) min in group P; this was not significantly different from group C21.5(7-70) min. Over the first 24 hours the postoperative morphine requirement was significantly less in the two treatment groups 30(20)mg in group I and 34(17) mg in group P and 71(15) in group C, P < 0.0001. There were no apparent NSAID-induced side-effects, or effects on wound healing. The preoperative administration of piroxicam (15gm) topically compared favourably with a preoperative local anaesthetic field block with respect to VAS scores, time to first analgesia and total morphine consumption. And both treatment groups provided significantly superior analgesia than the control group.