[Hemodynamic and adrenergic effects of flumazenil after general anesthesia with flunitrazepam]

Reversal of benzodiazepine-induced sedation by flumazenil has been reported to produce no or minor hemodynamic alterations although some adverse responses have been observed. To better delineate circulatory and adrenergic modifications induced by flumazenil, 20 consenting patients scheduled for short orthopedic procedures were included in a double blind controlled study. Anesthesia consisted in flunitrazepam (30 to 40 micrograms.kg-1) plus halothane (0.5 vol. % in N2O-O2, 60-40 vol. %) and alfentanil. At the end of surgery, patients received 15 minutes after discontinuation of halothane and N2O, either flumazenil (1 mg) or placebo according th randomization. Heart rate and blood pressure were obtained before reversal and repeatedly for 30 minutes following flumazenil or placebo. Level of consciousness was also assessed and blood samples were withdrawn for subsequent determination of plasma levels of norepinephrine. Flumazenil administration induced in all cases an immediate and total reversion of sedation while recovery was slow in the placebo group. No significant changes in heart rate and blood pressure values were found in both groups. By contrast, plasma levels of norepinephrine were significantly increased in all patients. It is concluded that reversal of benzodiazepine-induced sedation or anesthesia is not associated with significant variations of usual hemodynamic or adrenergic responses.