Influence of epinephrine as an adjuvant to epidural morphine for postoperative analgesia.

The influence of the addition of epinephrine to epidural morphine on postoperative analgesia were investigated in 60 ASA physical status I or II patients aged average 45 yr. The treatments were given following lower extremity operation under epidural anesthesia with 2% Xylocaine solution in 20 mL. The subjects were randomly divided into 2 groups. Group A (n = 30) received 2 mg epidural morphine in 10 mL normal saline without epinephrine. Group B (n = 30) received 2 mg epidural morphine in 10 mL normal saline with epinephrine 0.1 mg (1:100,000, 10 micrograms/mL). Patients were assessed for quality and duration of postoperative analgesia, as well as the incidence and severity of side effects after epidural morphine administration. The addition of epinephrine to epidural morphine had significantly increased the quality and duration of analgesia. The side effects of pruritus, nausea, vomiting, and urinary retention were more intense after epinephrine-morphine administration. However, respiratory depression was not observed in both groups.