Effects of Intravenous and Epidural Patient-Controlled Analgesia on Postoperative Pain and Knee Rehabilitation after a Unilateral Total Knee Replacement

Abstract

Background: Postoperative pain is a major concern after a total knee replacement (TKR). It hinders early intense physical therapy, the most influential factor for good postoperative knee rehabilitation. The purpose of this study was to compare intravenous patient-controlled analgesia (IV-PCA) using morphine and continuous ketorolac IV infusion with patient-controlled epidural analgesia (PCEA) using morphine and continuous bupivacaine infusion in terms of analgesic efficacy and postoperative knee rehabilitation after a unilateral TKR.

Methods: Eighteen patients undergoing a unilateral total knee replacement were randomly allocated to one of the two groups. In group IV-PCA (n = 9), 30 min before the end of surgery, patients received ketorolac 30 mg IV bolus followed by continuous infusion with ketorolac (5 mg/h) and IV-PCA with morphine (20μg/kg, lockout 10 min). In group PCEA (n = 9), 30 min before the end of surgery, patients received 2 mg morphine bolus followed by continuous infusion with 0.1% bupivacaine (2 ml/h) and PCEA with morphine (1 mg, lockout 15 min).

Results: There were significant differences in visual analogue scale scores at the first 2-hours after the unilateral TKR, cumulative morphine consumption and number of postoperative days required to obtain 90o knee flexion.

Conclusions: PCEA using a morphine-bupivacaine combination provided better pain relief and facilitated the continuous passive motion more than IV-PCA using a morphine-ketorolac combination. This results in possible faster postoperative knee rehabilitation.