Preoperative rectal diclofenac versus paracetamol for tonsillectomy: effects on pain and blood loss

Background: Diclofenac is widely used for postoperative analgesia but the p erioperative safety of this drug is controversial because of its effect on platelet aggregation, which might increase blood loss. In a prospective inv estigator-blinded study the effects of diclofenac and paracetamol on pain a nd blood loss were compared in patients undergoing tonsillectomy. Method: Ninety patients were randomised to receive rectal diclofenac 0.65-1 .0 mg.kg(-1) or paracetamol 13-20 mg.kg(-1) preoperatively. Ten patients we re excluded after randomisation. Pain was evaluated postoperatively by mean s of the visual analogue scale and by recording the use of pethidine for re scue analgesia. Perioperative blood loss was estimated from measured intrao perative blood loss; use of drugs to achieve haemostasis, and the incidence of reoperations. Results: Anaesthetic or surgical managements did not differ between the gro ups, but a significantly longer period of surgery was found in the diclofen ac group, 32+/-16 vs. 25+/-11. min (P = 0.024). Pain scores or pethidine co nsumption were not significantly different between the groups. Intraoperati ve blood loss was significantly larger in the diclofenac group, 1.9 (1.1-3. 1) vs. 1.1 (0.7-2.0) ml.kg(-1)(P = 0.007). Conclusion: Preoperative rectal diclofenac offers no advantage over paracet amol with respect to postoperative analgesia in tonsillectomy patients but increases intraoperative blood loss.