Dihydroergotamine in the prevention of hypotension associated with extradural anaesthesia.

The efficacy of a single dose of dihydroergotamine (DHE) 0.5 mg i.v. in preventing the decrease in arterial pressure resulting from extradural anaesthesia was studied in 47 patients; 24 received DHE and 23 a placebo, in a randomized double-blind manner. Although the decrease in systolic arterial pressure was more pronounced in the placebo group than in the DHE group, the difference was not significant. Diastolic and mean arterial pressures were both significantly lower in the placebo group than in the DHE group during the initial phase of extradural anaesthesia. Administration of DHE did not cause any significant changes in heart rate. In both groups the heart rate decreased significantly during the 5-h period following the induction of extradural anaesthesia. The patients in the placebo group needed additional medication to increase unacceptably low arterial pressures or heart rate more frequently than the patients in the DHE group.