Modulation of the adrenergic system in the treatment of postoperative bowel atonia

Sympathetic hyperactivity is considered to be the most important factor in the development of postoperative bowel atonia. In a double-blind study we evaluated the gut motor effects of dihydroergotamine, which predominantly acts as a sympatholytic agent in the gastrointestinal tract. Forty-six patients undergoing cholecystectomy received either 0.5 mg dihydroergotamine + 5000 U heparin or 5000 U heparin alone (controls) twice daily in a randomized order starting on the morning of the operation. The first postoperative bowel movement occurred 57 +/- 4 h (means +/- SEM) after operation in the patients receiving dihydroergotamine, compared with 102 +/- 4 h in the control patients (p less than 0.001). Electromyography performed in the stomach and upper small bowel on the 3rd postoperative day showed an increase in the number of activity fronts of the interdigestive migrating motor complex and in the duration of spike activity under the influence of dihydroergotamine compared with the controls (p less than 0.001). It is concluded that dihydroergotamine stimulates depressed gut motility after abdominal surgery and that sympatholysis is the likely mechanism of action.