title: Safety of labetalol-induced controlled hypotension during middle ear microsurgery.
abstract: In order to study the influence of labetalol on the peroperative oxygenation during deliberate hypotension, 50 patients undergoing middle ear microsurgery were randomly divided in two groups of 25 patients; one group receiving labetalol to induce hypotension, the other group receiving placebo in a double blind manner. In the group receiving labetalol the arterial oxygen tension (PaO2) decreased significantly 5 minutes after the intravenous bolus injection. Within 30 minutes the PaO2 returned to the starting level. The arterial carbon dioxide tension (PaCO2) increased within 5 minutes and also returned to the initial level after 30 minutes. These changes were absent in the control group. It is concluded that, although labetalol produces a statistically significant change in PaO2 and PaCO2, this finding has only minor clinical implications and so labetalol remains a safe drug to be used for the induction of deliberate hypotension during middle ear microsurgery.
authors.affiliation: Department of Anaesthesiology, University Hospital Antwerp.
authors.forename: S
authors.initials: S
authors.lastname: De Hert
authors.forename: E
authors.initials: E
authors.lastname: Boeckx
authors.forename: M
authors.initials: M
authors.lastname: Vercauteren
authors.forename: J
authors.initials: J
authors.lastname: Claes
authors.forename: P
authors.initials: P
authors.lastname: Van den Heyning
authors.forename: H
authors.initials: H
authors.lastname: Adriaensen
mesh_terms: D000328:Adult; D004432:Ear, Middle / Q000601:surgery*; D005260:Female; D006801:Humans; D007023:Hypotension, Controlled; D007741:Labetalol / Q000494:pharmacology*; D008297:Male; D008866:Microsurgery; D010100:Oxygen / Q000097:blood*; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects
chemical_list: D007741:Labetalol; D010100:Oxygen