EPIDURAL CLONIDINE OR SUFENTANIL FOR INTRAOPERATIVE AND POSTOPERATIVEANALGESIA

This study contrasts the efficacy and side effects of epidural clonidi ne and sufentanil in the perioperative period. Using a randomized, pro spective, double-blind study design, 40 patients undergoing abdominal surgery under propofol/nitrous oxide anesthesia were enrolled. Before anesthesia, an epidural catheter was inserted at the L1-L2 interspace. At induction of anesthesia, the patients received epidurally either c lonidine (4 mu g/kg in 10 mL) infused in 20 min followed by a 2-mu g . kg(-1). h(-1) infusion (5 mL/h) during 12 h (Group 1) or sufentanil(0 .5 mu g/kg in 10 mL) in 20 min followed by a 0.25-mu g . kg(-1). h(-1) infusion (5 mL/h) during 12 h (Group 2). Intraoperatively, increases in arterial blood pressure and heart rate not responding to propofol b olus (0.5 mg/kg) were treated with a bolus of intravenous (IV) sufenta nil 0.035 mu g/kg. Postoperatively, N sufentanil boluses (5 mu g) were given through a patient-controlled analgesia (PCA) device. Postoperat ive analgesia was assessed by recording the IV PCA sufentanil requirem ents and the patients' visual analog scale (VAS) at 3, 6, 12, 18, 24, 36, and 48 h. Sedation analog scales and side effects were also record ed. Plasma clonidine and sufentanil concentrations were measured after 20 min and 6, 12, and 24 h. The number of reinjections of propofol(n = 1.6+/-1.6 in Group 1 vs 6.5+/-4.0 in Group 2) and of IV sufentanil ( n = 0.6+/-0.8 in Group 1 vs 3.8+/-3.7 in Group 2) was significantly re duced (P < 0.001) in the epidural clonidine group. In the early postop erative period, pain scores and rescue analgesic requirements were ver y low in both groups. Af ter discontinuation of the epidural infusions , reduced PCA requirements and the better VAS scores were still noted in Group 1 (80.5+/-55.7 mu g IV sufentanil in Group 1 vs 142+/-87 mu g in Group 2; P < 0.05). There was no difference in sedation scores. Ep idural clonidine and sufentanil only moderately affected heart rate an d blood pressure. Two instances of awareness in Group 1 and one episod e of respiratory depression in Group 2 were reported. Epidural clonidi ne improved intraoperative hemodynamic stability when compared with ep idural sufentanil. Both substances provided reliable postoperative ana lgesia. A longer lasting residual analgesic effect was demonstrated af ter the use of epidural clonidine. Both substances showed different bu t potentially worrying side effects.