HYPERTENSIVE CRISIS: HYPERTENSIVE EMERGENCIES AND URGENCIES

Pridady*

Keywords: : hypertensive, emergencies, urgencies

Abstact

Hypertension affects an estimated 50 million people in the United States, and it contributed to more than 250,000 deaths in the year 2000 because of end-organ damage. Normal blood pressure is defined as a systolic blood pressure of less than 120 mm Hg and diastolic blood pressure of less than 80 mm Hg. Hypertension is defined as a sys- tolic blood pressure of 140 mm Hg or higher or a diastolic blood pressure of 90 mm Hg or higher. A systolic blood pressure of 120 to 139 mm Hg or a diastolic blood pressure of 80 to 89 mm Hg is considered prehypertension, because people in this range of blood pressure have higher tendency to develop hypertension over time. There is a con- tinuous, graded relationship between hypertension and cardiovascular risk; even a slightly elevated blood pressure increases risk for cardiovascular disease. The maximum blood pressure as well as the duration of elevated pressure determines the outcome. Most patients who have chronically uncontrolled hypertension suffer end-organ dam- age over time. Patients with previously untreated or inadequately treated high blood pressures are most prone to acute rises in their blood pressures. Patients with secondary causes of hypertension are at higher risk of acute rises of blood pressure than patients who have essential hypertension. The terms ‘‘malignant hypertension, ‘hypertensive emergency,’’ and ‘‘hypertensive urgency’’ were instituted to describe these acute rises in blood pressure and resulting end-organ damage. Hypertensive crisis includes hypertensive emer- gencies and urgencies. Hypertensive emergency is defined as severe hypertension with acute end- organ damage, such as aortic dissection, heart failure, papilledema, or stroke. Although there is no blood pressure threshold for the diagnosis of hypertensive emergency, most end-organ damage is noted with diastolic blood pressures exceeding 120 to 130 mm Hg. In these patients, immediate but monitored reduction, often accomplished with parenteral medications, is essential in preventing long-term damage. Hypertensive urgency, on the other hand, describes significantly elevated blood pressure but without evidence of acute end-organ damage. These patients also need reductions in their blood pressures; but these reductions can be achieved over a period of days, with oral medi- cations and usually without an intensive monitoring setting.

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