Hypertensive crisis

Hypertensive crises have historically been classified as hypertensive emergency or hypertensive urgency, although the latter term is potentially misleading. When evaluating patients with severe elevations in blood pressure, the primary consideration in determining the need for rapid treatment is the presence of acute target-organ dysfunction. Target organs affected predominately include those of the cardiovascular, renal, or central nervous systems. Although severe hypertension is commonly defined as blood pressure greater than 180/120 mm Hg, there is no absolute value of blood pressure that dictates urgent treatment. Patients with hypertensive emergency and associated end-organ damage will benefit from aggressive reductions in blood pressure, while patients with isolated severe hypertension may be harmed by similarly aggressive treatment measures.

Nearly one in four US emergency department (ED) patients have a hypertension-related diagnosis. Although severe hypertension is frequently seen in the ED, true hypertensive emergencies account for less than 1% of ED visits. Cardiac and neurologic emergencies are the most common manifestations of target-organ damage associated with hypertensive emergency.

Most cases of hypertensive crisis occur in patients with a known diagnosis of hypertension and are a result of medication non-adherence. Severe hypertension may also occur with the use of illicit drugs (e.g., cocaine, methamphetamines) and nonillicit drugs (e.g., nasal decongestants, nonsteroidal anti-inflammatory drugs, glucocorticoids). Various withdrawal syndromes (alcohol, benzodiazepines, clonidine) may present with severe hypertension. Further precipitating factors may include excessive sodium intake, acute psychiatric emergencies, acute pain syndromes, strokes, heart failure, and renal failure. Preeclampsia or eclampsia with severe hypertension may occur in pregnancy or in the early postpartum period. Less common causes of acute severe hypertension include pheochromocytoma, endocrine emergencies such as thyrotoxicosis or Cushing’s syndrome, and scleroderma renal crisis.

Acute severe hypertension may be either the precipitating factor or a consequence of various hypertensive emergencies. Life-threatening manifestations of target-organ dysfunction associated with severe hypertension include acute coronary syndrome, acute heart failure, aortic dissection, ischemic stroke, intracranial hemorrhage, hypertensive encephalopathy, including the posterior reversible leukoencephalopathy syndrome (PRES), renal failure, and eclampsia. These syndromes may occur in patients with or without a preexisting hypertension diagnosis.

A detailed history is helpful in assessing patients with hypertensive crisis and should elucidate the presence or absence of symptoms suggesting target-organ damage. Obtain a thorough medication history, including timing, dosages, and compliance with both prescribed and over-the-counter medications. The social history will include screening for the use of illicit substances and alcohol, as well as an assessment of social determinants of health that may impact adherence to therapies and dietary recommendations. A full review of systems may elucidate less common precipitating factors of severe hypertension (e.g., thyrotoxicosis). Past medical history is helpful in evaluating for preexisting conditions associated with organ damage or risk of developing organ damage, including current or recent pregnancies.