Background and objective: To determine whether prior exposure of non-steroidal anti-inflammatory drugs increases perioperative blood loss associated with major orthopaedic surgery.

Methods: Fifty patients scheduled for total hip replacement were allocated to two groups (double blind, randomized manner). All patients were pretreated for 2 weeks before surgery: Group 1 with placebo drug, Group 2 with ibuprofen. All patients were injected intrathecally with bupivacaine 20 mg plus morphine 0.1 mg, in a total volume of 4 mL, to provide surgical anaesthesia.

Results: The presence of severe adverse effects caused eight patients in the ibuprofen group and six in the placebo group to terminate their participation in the trial. The perioperative blood loss increased by 45% in the ibuprofen group compared with placebo. The total (±SD) blood loss in the ibuprofen group was 1161 (±472) mL versus 796 (±337) mL in the placebo group.

Conclusions: Pretreatment with ibuprofen before elective total hip surgery increases the perioperative blood loss significantly. Early discontinuation of non-selective non-steroidal anti-inflammatory drugs is advised.