Hypertensive crises. The need for urgent management.

Although hypertensive crises are now relatively uncommon, they often are life-threatening when they do occur and demand early recognition and management to minimize morbidity and mortality. Most patients have essential hypertension, and withdrawal from an antihypertensive drug is the most common cause of acute elevation of blood pressure. Short-acting parenteral agents are generally recommended for management of hypertensive crises. In most patients with hypertensive emergencies, the mean arterial pressure is lowered 25% over 2 to 4 hours. Both cerebral and coronary hypoperfusion must be avoided.