72-hour epidural infusion of 0.125% levobupivacaine following total knee replacement: a prospective, randomized,...

To evaluate the efficacy in terms of pain relief and degree of motor impairment of a continuous epidural infusion of 0.125% levobupivacaine in patients undergoing total knee replacement surgery.

186 patients receiving effective epidural analgesia with 0.125% levobupivacaine during the first 24 hours after surgery were randomly allocated to receive postoperative analgesia for the following 48 hours consisting in either a continued epidural infusion of 0.125% levobupivacaine (Levobupivacaine group, n = 96), or IV PCA morphine only (Morphine PCA group, n = 90). An independent observer recorded the average amount of morphine required per hour following randomisation, pain intensity, degree of motor blockade and occurrence of side effects.

Median (range) hourly morphine consumption during the study period was 0.21 (0.00-4.65) mg/hr in the Levobupivacaine group and 0.43 (0.04-4.65) mg/hr in the Morphine PCA group (P = 0.005). The quality of pain relief was adequate (VAS < 30 mm) in both groups, but patients in the Levobupivacaine group showed lower VAS values during motion than patients in the Morphine PCA group (P = 0.001). No differences in the proportion of patients with clinically relevant motor block (Bromage's score > or = 1) were reported between the two groups.

Continuing the epidural infusion of a concentration of levobupivacaine as low as 0.125% improves pain relief with a 50% reduction of hourly morphine consumption after total knee replacement even during the second and third postoperative days, and does not result in a gross impairment of motor function.