The efficacy and safety of epidural infusions of levobupivacaine with and without clonidine for postoperative pain relief in patients undergoing total hip replacement

We assessed the efficacy and tolerability of epidural infusions of levobupi vacaine, levobupivacaine plus clonidine, and clonidine for postoperative an algesia in 86 patients undergoing total hip replacement. For each group, an epidural cannula was inserted before surgery and 15 mL of 0.75% plain levo bupivacaine was administered. Three hours later, an epidural infusion (6 mL /h) of levobupivacaine 0.125% (L), levobupivacaine 0.125% plus clonidine 8. 3 mu g/mL (LC) or clonidine alone (8.3 mu g/mL) (C) was initiated. Morphine consumption was recorded for the following 24 h as were visual analog pain scores and the degree of sensory and motor blockade. The mean (median) mor phine consumption was lowest in the combination group (LC),14 (7) mg; highe r in the clonidine group (C), 23 (21) mg; and highest in the levobupivacain e group (L), 37 (36) mg (P = 0.022). The median times until the first reque st for analgesia which were 2.9, 5.9, and 12.5 h for Groups L, C, and LC, r espectively (P less than or equal to 0.01). There were no statistical diffe rences among the groups regarding the maximum degree of postoperative motor blockade. On average, the systolic blood pressure in the two clonidine gro ups was slightly lower than in those from the levobupivacaine group. We con clude that the epidural administration of a combination of levobupivacaine plus clonidine is well tolerated and gives better analgesia than either dru g used alone.