Local infiltration analgesia with levobupivacaine compared with intrathecal morphine in total hip arthroplasty patients.

BACKGROUND: Recently, local infiltration analgesia (LIA) has been promoted for pain control after total hip arthroplasty (THA). We hypothesized that LIA would offer equal analgesic efficacy but less adverse effects, e.g., nausea and vomiting, when compared with an established regimen [intrathecal morphine (it-M)] after THA.

METHODS: This randomized controlled trial comprised 60 patients undergoing THA under spinal anaesthesia. For LIA, the surgeon administered levobupivacaine, ketorolac and epinephrine at the surgical site intraoperatively. LIA patients received a LIA top-up through a wound catheter on the morning of the 1st post-operative day (POD). In group it-M, 0.1 mg morphine was given together with the spinal anaesthetic. Study parameters included pain scores, vital parameters and side effects, e.g., post-operative nausea and vomiting (PONV). Besides, levobupivacaine plasma concentrations were determined in 10 LIA patients.

RESULTS: The median (25th/75th percentiles) rescue oxycodone demand differed significantly with LIA 15 (10/25) mg vs. 8.5 (1.5/15) mg with it-M (P < 0.006) during the day of surgery, but not anymore on 1st or 2nd POD. The LIA top-up had no effect. However, both analgesic regimens resulted in comparable pain scores and patient satisfaction. PONV incidence and medication did not vary significantly. LIA offered certain advantages regarding early post-operative mobilization. Maximum levobupivacaine plasma concentrations (229-580 ng/ml) remained under the toxic level.

CONCLUSIONS: While LIA might enable earlier mobilization after THA, it was not associated with less nausea as compared with it-M. Less rescue oxycodone was given early after it-M, but urinary retention was more common in that group.