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.