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

Background: Diclofenac is widely used for postoperative analgesia but the perioperative safety of this drug is controversial because of its effect on platelet aggregation, which might increase blood loss. In a prospective investigator-blinded study the effects of diclofenac and paracetamol on pain and 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 were excluded after randomisation. Pain was evaluated postoperatively by means of the visual analogue scale and by recording the use of pethidine for rescue analgesia. Perioperative blood loss was estimated from measured intraoperative blood loss; use of drugs to achieve haemostasis, and the incidence of reoperations. Results: Anaesthetic or surgical managements did not differ between the groups, but a significantly longer period of surgery was found in the diclofenac group, 32+/-16 vs. 25+/-11. min (P = 0.024). Pain scores or pethidine consumption were not significantly different between the groups. Intraoperative 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 paracetamol with respect to postoperative analgesia in tonsillectomy patients but increases intraoperative blood loss.