[Treatment of hypertension emergencies]

Hypertensive emergencies are defined as situations where a seriously elevated blood pressure threatens the patients life or vital organ functions. Since treatment of hypertensive emergencies by a rapid reduction of blood pressure can be complicated by serious unwanted effects, the treatment indications should be defined cautiously. In addition the principles of autoregulation of blood flow and vascular resistance in hypertensive patients should be considered as well as the widely differing effects of the drugs used in hypertensive emergencies like alpha- and beta-adrenergic blocking substances, central sympatholytics and vasodilating agents. A reduction of cardiac output as a consequence of betablockade or central sympatholytics may be beneficial in patients with aneurysms, but may result in severe central hypoperfusion in others which can also be induced by vasodilators by local and systemic steal effects. Therefore we propose a treatment scheme for hypertensive emergencies based on pathophysiological considerations with special regard to cerebral perfusion. In many instances calcium-antagonists can be considered as drugs of first choice since they lower blood pressure in relation to pretreatment blood pressure and have only a weak negative inotropic effect. In addition they exert their vasodilating action predominantly in vessels with a high vasoconstrictor tone and do not reduce cerebral perfusion despite a marked reduction of blood pressure within a short time. In every case the initial emergency treatment should be followed by a careful long term management of hypertension.