Flumazenil in intensive care. The duration of arousal after an assessment dose

The effect of an assessment dose of the benzodiazepine antagonist flumazenil was studied in 20 patients in an intensive care unit. The patients had been sedated with alfentanil and midazolam, and were ready to be weaned from mechanical ventilation. In 10 patients flumazenil was titrated just to produce full arousal whilst the midazolam infusion was continued; flumazenil administration was repeated one hour later after the infusion of midazolam had been stopped. In another 10 patients, flumazenil was administered only once, coinciding with the cessation of sedation. The duration of full arousal in both groups was less than 15 minutes in 75% of patients given a single dose of flumazenil (median dose 0.4 mg) although some effect persisted for up to 60 minutes. The cardiovascular effects of arousal were transient and probably not clinically significant. A brief duration of action is advantageous if the patient is found still to require sedation.