title: Cardiovascular effects of labetalol during halothane anaesthesia.
abstract: 1 The circulatory effects of labetalol 25 mg intravenously in six patients during 1% halothane anaesthesia were studied. 2Labetalol caused a marked decrease in arterial pressure and a consistent but modest (20%) decrease in cardiac output. Heart rate was slowed and stroke volume did not change significantly. Central venous pressure increased and peripheral resistance decreased. 3 Increasing the halothane concentration of 3% led to marked myocardial depression as evidenced by reduced cardiac output and increased central venous pressure with increasing arterial hypotension. 4 Labetalol may be a suitable drug for controlling induced hypotension under general anaesthesia, although high concentrations of halothane should be used with care.
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002496:Central Venous Pressure / Q000187:drug effects; D004983:Ethanolamines / Q000494:pharmacology*; D006221:Halothane / Q000008:administration & dosage; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007023:Hypotension, Controlled; D007275:Injections, Intravenous; D007741:Labetalol / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D004983:Ethanolamines; D007741:Labetalol; D006221:Halothane