Impact on postoperative pain of long-lasting pre-emptive epidural analgesia before total hip replacement: a...

Clinical studies on pre-emptive analgesia have produced inconsistent results. We conducted a clinical study investigating the effect of long-lasting pre-emptive epidural analgesia on consumption of analgesics and acute pain. Forty-two patients scheduled for elective hip replacement for osteo-arthritis were randomly assigned to receive, on the day before operation, either 5 ml.h(-1) ropivacaine 0.2% (study group, n = 21) or 5 ml.h(-1) saline (control group, n = 21). Postoperative analgesia was achieved in both groups by patient-controlled epidural analgesia (PCEA) with ropivacaine 0.2%. The main outcome measure was consumption of local anaesthetics. Additional parameters included visual analogue pain scale (VAS) scores, consumption of rescue analgesics, requests for PCEA boluses, and side-effects. The pre-operative parameters and pain scores were similar in the two groups. Epidural blocks provided sufficient operative analgesia in all patients. Pre-emptive analgesia was continued for 11-20 h and led to significantly decreased pain scores before surgery. The consumption of local anaesthetics was decreased postoperatively in the study group (194 mg vs. 284 mg in the postoperative period). Furthermore, bolus requests occurred more frequently in the control group. VAS scores did not differ significantly between groups. Long-lasting "pre-emptive" epidural analgesia decreases postoperative pain with improved pain control.