Laboratory Studies
Hypertensive encephalopathy is a diagnosis of exclusion; other potential causes of the symptoms must be evaluated in the workup as indicated by the clinical findings. Evaluation includes determining the extent of hypertensive damage and excluding intracranial processes. Laboratory and radiologic studies do not take the place of a careful history and physical examination (see Presentation).
Obtain a complete blood count (CBC) to determine whether microangiopathic hemolytic anemia is present. Perform a urinalysis, and measure blood urea nitrogen (BUN) and creatinine levels; with hypertensive nephropathy, an elevated creatinine with hematuria and casts may be present. Order cardiac enzyme studies to exclude myocardial ischemia. Perform a urine toxicology screen to help exclude drug-induced hypertensive encephalopathy.
CT, MRI, Plain Radiography, and ECG
Consider computed tomography (CT) or magnetic resonance imaging (MRI) of the head to look for indications of stroke, hemorrhage, or intracranial masses.
Obtain chest radiographs to evaluate for possible complications of hypertensive encephalopathy, including aspiration due to altered mentation. Chest radiographs can also be used to evaluate for other conditions, such as acute pulmonary edema and aortic dissection.
Perform electrocardiography (ECG) to evaluate for the presence of cardiac ischemia.
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Papilledema. Note the swelling of the optic disc, with blurred margins.
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Hypertensive retinopathy. Note the flame-shaped hemorrhages, soft exudates, and early disc blurring.
