[Circulatory changes with urapidil (Ebrantil) in general and regional anesthesia. Studies with normo- and...

Urapidil (Ebrantil) is a new antihypertensive agent exerting central and peripheral action which is recognized for the treatment of both chronic and acute hypertension. The purpose of the present study was to investigate the extent of the antihypertensive effect of urapidil in various forms of general or regional anaesthesia. To this end, a retrospective analysis was first carried out on the typical reactions of the circulatory system in 200 patients during either neuroleptanalgesia with diazepam and droperidol, or halothane, enflurane or intrathecal local anaesthesia. In a prospective study, each of 5 normo- or hypertensive patients undergoing elective surgery with one of the aforementioned anaesthetic procedures received 50 mg urapidil intravenously 25-30 min after start of anaesthesia. Blood pressure and heart rate measurements were performed for up to 24 h after the injection. Whereas anaesthesia alone caused a moderate drop in systolic and diastolic blood pressure of 3.1 and 2.1%, respectively (in normotensive patients), and of 12.0 and 6.7%, respectively (in hypertensive patients), urapidil caused a further significant fall in blood pressure in the hypertensive patients within a few minutes, but not in the normotensive groups. This effect was particularly pronounced under spinal anaesthesia and usually persisted until the end of the operation. Heart rate was (not significantly) increased for a few minutes after administration of urapidil. Temporary blood pressure reduction to hypotensive values was observed in 2 of the 50 patients only. From the results it is concluded that urapidil is an effective and relatively safe drug for the treatment of elevated blood pressure during routine surgery. Even if it has been administered on the basis of wrong indication (e.g. hypertensive phases as a result of insufficient anaesthesia), it rarely will cause blood pressure to fall to undesired low levels after anaesthesia has been normalized.