Effect of Preemptive Analgesia on Postoperative Pain after Total Knee Arthroplasty

Abstract

Background: Postoperative pain management is critical for optimal care of orthopedic surgical patients. Preemptive analgesia such as neuraxial blocks and methods of drug delivery system such as infusion pumps may be used after total knee arthroplasty. The aim of this study was to examine the analgesic and pre-emptive effect of continuous epidural block initiated before total knee arthroplasty upon postoperative period. Methods: A double-blind randomized study was performed in thirty-nine patients scheduled for total knee arthroplasty. Group 1 (n = 20) received continuous epidural block with 2% lidocaine 15 ml initiated 20 min before general anesthesia (pre-emptive group) and Group 2 (n = 19) received continuous epidural block postoperatively, followed by a continuous epidural infusion with 0.125% bupivacaine and fentanyl until 72 hr after operation. In both groups general anesthesia was done. Preoperative vital signs and post-incisional vital signs were checked. VAS score were recorded at 1, 2, 3, 4, 5, 6, 7 days postoperatively and side effects and patients satisfaction were assessed. Results: VAS at rest was significantly less (P ＜ 0.05) in group 1 than group 2 between 2 days and 7 days after surgery except 1 day after surgery. There was no intergroup difference in the incidence of side effects. More patients in group 1 were satisfied than group 2. Conclusions: Preoperative continuous epidural block in total knee arthroplasty reduces postoperative pain and the timing of analgesic treatment is most important to obtain effective analgesia.