Labetalol in controlled hypotension: administration of labetalol when adequate hypotension is difficult to achieve.

A study of controlled hypotension was undertaken in 50 major surgical patients using labetalol, a drug with both alpha- and beta-adrenoceptor blocking activity. The patients were such that difficulty in achieving controlled hypotension could be anticipated: the young, the anxious and those for whom halothane was contraindicated. The administration of labetalol quickly induced hypotension which was controlled easily and was rapidly antagonized.