Management of Hypertensive Crises

Abstract

Hypertensive emergencies are life-threatening conditions because their course is complicated with acute target organ damage. They can present with neurological, renal, cardiovascular, microangiopathic hemolytic anemia, and obstetric complications. After diagnosis, they require the immediate reduction of blood pressure (in <1 hour) with intravenous drugs such as sodium nitroprusside, administered in an intensive care unit. These patients present with a mean arterial pressure >140 mm Hg and grade III to IV retinopathy. Only occasionally do they have hypertensive encephalopathy, reflecting cerebral hyperperfusion, loss of autoregulation, and disruption of the blood-brain barrier. In hypertensive emergencies, blood pressure should be reduced about 10% during the first hour and another 15% gradually over the next 2 to 3 hours to prevent cerebral hypoperfusion. The exception to this management strategy is aortic dissection, for which the target is systolic blood pressure <120 mm Hg after 20 minutes. Oral antihypertensive therapy can usually be instituted after 6 to 12 hours of parenteral therapy. Hypertensive urgencies are severe elevations of blood pressure without evidence of acute and progressive dysfunction of target organs. They demand adequate control of blood pressure within 24 hours to several days with use of orally administered agents. The purpose of this review is to provide a rational approach to hypertensive crisis management.

Clinical Presentation of Hypertensive Crises in Emergency Medical Services

“…Depending on whether there is damage to vital organs or not, we can distinguish between hypertensive emergency and hypertensive urgency. Hypertensive emergencies are life-threatening conditions because their outcome is complicated by acute damage to vital organs, and can be presented with neurological, renal, cardiovascular, microangiopathic and obstetric complications (5). Hypertensive emergencies include hypertensive encephalopathy, hypertensive acute left ventricular relaxation associated with acute myocardial infarction or unstable angina, aortic dissection, subarhnoic hemorrhage, ischemic stroke, and severe pre-eclampsia or eclampsia (2).…”

Evaluation and Treatment of Hypertensive Urgencies and Emergencies

“…It is easily titrated, is inexpensive, and has a long record of effectiveness in treating hypertensive emergencies of nearly all types. 6,8,10,19 Limitations of nitroprusside use include the need for invasive BP monitoring and its metabolic products (thiocyanate and cyanide), which contraindicate its use in pregnancy and limit the time used (48 hours) in patients with renal or hepatic dysfunction. Nitroprusside is reported to increase intracranial pressure in high doses, to obliterate cerebral autoregulation, and to reduce regional coronary blood flow, which could limit its usefulness in patients with neurologic complications or acute coronary syndromes.…”

Pharmacokinetics and tissue distribution of clevidipine and its metabolite in dogs and rats

“… Chronic hypertension is among the most common medical conditions [1] , which is usually well-controlled through oral antihypertensive drugs. However, subjects with acute, severe hypertension or in the cases of cardiac surgery require intravenous therapy when rapid, controlled blood pressure reduction is necessary and the administration of oral agents is not feasible [2][3][4] . The ideal therapeutic profile for an intravenous antihypertensive agent consists of rapid action, predictability, easy titratability, short duration after discontinuation, and minimal risk of side effects [4][5][6][7] .…”