Résumé
Epidural narcotics has been most widely used for the control of postoperative pain. However, patients have been treated insufficiently because of the fear of respiratory depression. Urinary retension, nausea and vomiting, pruritus are other complications of epidural narcotics. Epidural local anesthetics may be an alternative to epidural narcotics. But the duration of action is usually too short, although epinephrine can prolong the analgesic effect. Clonidine, an a2-adrenergic agonist has its own analgesic effect and can prolong the effects of epidurally administered drugs. Therefore epidural clonidine may be expected to lessen the requirement of epidural narcotics and hence reduce the complications of narcotics. 75 ug or 150ug of clonidine was added to 0.125% bupivacaine or 2 mg of morphine. 6ml of mixed solution was administered epidurally during and after operation for the control of pain following upper abdominal surgery. Clonidine caused increase in the analgesic duration of epidural bupivacaine and morphine. Clonidine also cause decrease in systolic pressure in dose-dependent manner, especially during anesthesia without significant alterations in heart rate. Clonidine may be an useful adjunct to epidural narcotics, provided the dosage is carefully titrated in the range of modest hemodynamic change.