Background: Comparative postoperative non-steroidal anti-inflammatory drug (NSAID) studies in orthopedic patients have usually been restricted in time to the first postoperative day. The opioid-sparing effect of NSAIDs may be beneficial postoperatively as long as pain otherwise restricts ambulation and rehabilitation. We therefore compared the analgesic efficacy of the maximum recommended doses of diclofenac and ketoprofen for 3 days after knee arthroplasty.
Methods: We studied 64 knee arthroplasty patients, operated on under spinal anesthesia. In a randomized, double-blind and placebo-controlled fashion, the patients received either i.v. diclofenac 75 mg (n = 24), ketoprofen 100 mg (n = 24) or saline (n = 16) in the recovery room, followed by oral diclofenac 150 mg/day, ketoprofen 300 mg/day or placebo, respectively, for 3 days, supplemented by patient-controlled analgesia (PCA) with i.v. oxycodone.
Results: The mean consumption of oxycodone during the first, second and third study days was 45.3, 22.3 and 15.2 mg in the diclofenac group, 43.5, 37.5 and 21.8 mg in the ketoprofen group, and 61.2, 45.9 and 36.1 mg, respectively, in the placebo group. Oxycodone consumption was significantly lower (P < 0.05) in the ketoprofen group than in the placebo group in the postoperative period 13-24 h and 61-72 h. Diclofenac was superior to placebo in the postoperative period 25-48 h (P < 0.01), 49-60 h (P < 0.05) and to ketoprofen at 49-60 h (P < 0.05). During administration of diclofenac on days 1-3 and ketoprofen on day 2, the mean pain scores (VAS) were lower than in the placebo group (P < 0.05). Six patients had difficulties in operating the PCA device. There were no differences in blood loss.
Conclusion: We conclude that in the first day after knee arthroplasty (13-24 h), ketoprofen exerted an opioid-sparing effect. After day 1 (25-60 h), with the doses used, diclofenac proved to be better than placebo, whereas ketoprofen was not.