Analgesia after total hip replacement : epidural versus psoas compartment block

Abstract

Introduction Both epidural anaesthesia and psoas compartment block have been advocated for analgesia after hip replacement. The aim of this study was to evaluate the effectiveness of a psoas compartment block, as compared to an epidural, for postoperative analgesia following total hip replacement surgery. Method Patients scheduled for total hip replacement surgery were randomly allocated to one of two groups, one group receiving an epidural, and the other a psoas compartment block preoperatively. An infusion of bupivacaine 0.167% was continued postoperatively for 24h. Postoperative pain was assessed at 0, 1, 4, 8 and 24 hours using the visual analogue pain score (VAPS). The amount of local anaesthesia, need for additional morphine, as well as any side effects, was recorded. Results Thirty-six patients completed the study, 18 in each group. There was no significant difference between the two groups regarding VAPS at the different times (p = 0.4246), but local anaesthetic and opiate consumption was significantly higher in the psoas compartment block group. Postoperative morphine as co-variate had a significant influence on the mean postoperative VAPS (p = 0.0066). There was no significant difference between the number of side effects in each group (p = 0.3377). Conclusion Epidural analgesia was more effective than the psoas compartment block after hip replacement surgery. Although pain did not differ significantly, local anaesthetic and opiate consumption was significantly higher in the psoas compartment group.