I.V. LABETALOL IN THE TREATMENT OF HYPERTENSION FOLLOWING CORONARY-ARTERY SURGERY

• Published in: British journal of anaesthesia : BJA 1982-11, Vol.54 (11), p.1191-1196
• Main Authors: MOREL, D.R., FORSTER, A., SUTER, P.M.
• Format: Article
• Language: English
• Subjects: Aged; Blood Pressure - drug effects; Ethanolamines - therapeutic use; Heart Rate - drug effects; Humans; Hypertension - drug therapy; Hypertension - etiology; Injections, Intravenous; Labetalol - administration & dosage; Labetalol - therapeutic use; Middle Aged; Myocardial Revascularization - adverse effects; Syndrome; Tachycardia - drug therapy; Tachycardia - etiology
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/54.11.1191

The cardiovascular effects of incremental fixed i.v. doses of labetalol were evaluated in 10 normovolaemic sedated patients presenting with hypertension and tachycardia in the early period after myocardial revas-cularizaoon. A first dose of 20 mg was sufficient to provoke a (P < 0.01) mean decrease in systolic (-9.3%), diastolic (-8.2%) and mean arterial (-7.9%) pressure (AP) and in the rate-pressure product (RPP) (-13.1%). The mean heart rate (HR) did not change significantly, but a linear correlation could be established between the change at 2 min and the value before injection (r = 0.73). A second dose of labetalol 40 mg given S min later did not decrease AP further, but a significant decrease in HR was noted. A marked difference in the individual response among patients was found as the range of effective total doses per kg body weight was 0.6–4.1 mg kg-1 (mean 2.2). Apart from one patient, no patient needed vagolytic or sympathomimetic drugs to oppose the alpha or beta actions of labetalol during the 24-h follow-up period.