Malignant hypertension must be treated expeditiously to prevent complications such as hypertensive encephalopathy, acute hypertensive heart failure, and renal failure. The traditional approach to patients with malignant hypertension has been the initiation of potent par-enteral agents. Listed are the settings in which parenteral antihy-pertensive therapy is mandatory in the initial management of malignant hypertension. Parenteral therapy generally should be used in patients with evidence of acute end-organ dysfunction or those unable to tolerate oral medications. Nitroprusside is the treatment of choice for patients requiring parenteral therapy. Diazoxide, employed in minibolus fashion to avoid sustained overshoot hypotension, may be advantageous in patients for whom monitoring in an intensive care unit is not feasible. It generally is safe to reduce the mean arterial pressure by 20% or to a level of 160 to 170 mm Hg systolic over 100 to 110 mm Hg diastolic. The use of a short-acting agent such as nitroprusside has obvious advantages because blood pressure can be stabilized quickly at a higher level if complications develop during rapid blood pressure reduction. When no evidence of vital organ hypoperfusion is seen during this initial reduction, the diastolic blood pressure can be lowered gradually to 90 mm Hg over a period of 12 to 36 hours. Oral antihypertensive agents should be initiated as soon as possible to minimize the duration of parenteral therapy. The nitroprusside infusion can be weaned as the oral agents become effective. The cornerstone of initial oral therapy should be arteriolar vasodilators such as calcium channel blockers, hydralazine, or minoxidil. Usually, ^-blockers are required to control reflex tachycardia, and a diuretic must be initiated within a few days to prevent salt and water retention, in response to vasodilator therapy, when the patient's dietary salt intake increases. Diuretics may not be necessary as a part of initial parenteral therapy because patients with malignant hypertension often present with volume depletion (Fig. 8-20).
Many patients with malignant hypertension definitely require initial parenteral therapy. However, some patients may not yet have evidence of cerebral or cardiac dysfunction or rapidly deteriorating renal function and therefore do not require instantaneous control of blood pressure. These patients often can be managed with an intensive oral regimen, often with a ^-blocker and minoxidil, designed to bring the blood pressure under control within 12 to 24 hours. After the immediate crisis has resolved and the patient's blood pressure has been controlled with initial parenteral therapy, oral therapy, or both, lifelong surveillance of blood pressure is mandatory. If blood pressure control lapses, malignant hypertension can recur even after years of successful antihypertensive therapy. Triple therapy with a diuretic, ^-blocker, and a vasodilator often is required to maintain satisfactory long-term blood pressure control.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...