Comparison of analgesic efficacy of oxycodone and fentanyl after total hip replacement surgery: A randomized controlled trial.

Background: Total hip replacement (THR) is often accompanied by severe postoperative pain. We aimed to study whether oxycodone can be an effective alternative for fentanyl in the management of early postoperative pain after total hip replacement.

Methods: We conducted a randomized controlled trial on 46 patients scheduled to undergo THR. We followed a standard general anesthetic technique, with endotracheal intubation. Twenty minutes before the end of surgery, single bolus injection of fentanyl, 50 μg (fentanyl group [group F], n = 23) or oxycodone, 4 mg (oxycodone group [group O], n = 23) was administered intravenously. Numeric rating scale (NRS) was used to assess pain in the post-anesthesia care unit (PACU). All patients had intravenous patient-controlled analgesia (PCA) with 10 μg/kg of fentanyl for 48 hours. Intravenous boluses of 50 μg were administered for breakthrough pain. The cumulative opioid dose administered at 6, 12, 24, and 48 h after surgery were recorded. A P value of less than .05 was considered statistically significant.

Results: The NRS of group O in the PACU was significantly lower (P <.05); fewer patients in group O required additional fentanyl boluses in the PACU (P <.05). The cumulative opioid requirement was significantly less in group O at 6, 12, 24, and 48 hours after surgery. (P <.05) CONCLUSIONS:: A single bolus injection of oxycodone is more effective than that of fentanyl in the acute phase of postoperative pain after THR. It may be used as an alternative drug for fentanyl in pain control after orthopedic surgery.