[Deliberate hypotension during rhinosurgery using labetalol, a combined alpha- and beta-adrenoceptor antagonist (author's transl)].
In 70 patients undergoing rhinosurgical operations, the applicability of labetalol, a drug that blocks both alpha- and beta-adrenoceptors, to intraoperative deliberate hypotension was studied. Anaesthesia was induced with diazepam/fentanyl or thiopental/fentanyl and maintained with N2O/O2 (2:1) and enflurane. Additionally, in combination with 0.3-0.5 mg/kg labetalol intravenously, enflurane was used for lowering arterial blood pressure. The average concentrations of enflurane needed to decrease the systolic pressure to values between 75 and 90 mm Hg in normotensive patients, ranged from 0.6 to 1.2 vol. % (mean 0.92 +/- 0.28). The heart rate was virtually stable throughout the operating procedure. After discontinuation of enflurane and administration of 0.01 mg/kg atropine, the blood pressure promptly returned to its preanaesthetic level and then remained constant during the postoperative period. From the results of this study it may be concluded that, combined with small amounts of inhalational anaesthetics, e.g. enflurane, labetalol (0.5 mg/kg) can safely be used for achieving hypotensive blood pressure levels during operations lasting 90 minutes maximum. Impending major blood losses and contraindications for the use of beta-blockers have to be excluded.
D000328:Adult; D000758:Anesthesia; D001794:Blood Pressure / Q000187:drug effects; D004737:Enflurane; D004983:Ethanolamines / Q000627:therapeutic use*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods*; D007741:Labetalol / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012225:Rhinoplasty
D004983:Ethanolamines; D004737:Enflurane; D007741:Labetalol
Blutdrucksenkung mit dem kombinierten Alpha-Beta-Rezeptorenblocker Labetalol in der Rhinochirurgie.