Comparison of epidural sufentanil plus clonidine with sufentanil alone for postoperative pain relief

Sufentanil 25 micrograms plus clonidine 1 microgram/kg administered epidurally was compared with epidural sufentanil 50 micrograms alone in a double-blind fashion for pain relief in 40 patients after abdominal surgery. The duration of complete pain relief was significantly longer in those who received the mixture. Oxygen saturation was reduced 10 and 20 minutes after sufentanil alone, but remained stable after sufentanil and clonidine. There were significant decreases in arterial blood pressure in the latter group that were maximum between 20 and 120 minutes after administration.