Evaluation and Management of Hypertension in the ICU

Benjamin M. Scirica

I. DEFINITIONS

A. Hypertensive crisis is defined as a severe elevation in blood pressure (BP).

1. The Joint National Committee (JNC) on Detection, Evaluation, and Treatment of High BP defines systolic blood pressure (SBP) >180 mm Hg and diastolic blood pressure (DBP) >120 mm Hg as hypertensive crises.

2. Hypertensive emergencies and urgencies are potentially life threatening and may occur with chronic essential hypertension, with secondary forms of hypertension, or de novo (Table 30-1).

B. Hypertensive emergencies and urgencies can be considered a continuum of disease but are differentiated by the presence or absence of acute and progressive target organ damage.

1. In hypertensive emergencies, BP elevation is associated with ongoing central nervous system (e.g., encephalopathy or hemorrhage), myocardial (e.g., ischemia, pulmonary edema), hematologic (e.g., hemolysis), or renal (e.g., acute renal failure) damage.

2. In hypertensive urgencies, the potential for organ damage is great and likely if BP is not soon controlled. These may be associated with symptoms such as headache, shortness of breath, or anxiety.

C. Accelerated hypertension and malignant hypertension traditionally referred to a hypertensive crisis with either early retinopathy (accelerated) or encephalopathy or nephropathy (malignant). These terms should not be used in current practice but rather referred to as acute severe hypertension or hypertensive emergencies.

II. APPROACH TO THE PATIENT

A. Immediate identification of both hypertension and potential organ damage is critical to properly triage patients. Patients with hypertensive emergencies should be admitted to an ICU setting for continuous monitoring and treatment.

B. In the ICU, therapy must often begin before a comprehensive patient evaluation is completed. A systematic approach offers the opportunity to be both expeditious and inclusive (Table 30-2).

TABLE 30-1 Examples of Hypertensive Crises and End Organ Damage

Generalized	Cardiovascular	Neurologic	Renal	Surgical
Accelerated and malignant hypertension	Acute left ventricular failure	Hypertensive encephalopathy	Acute renal failure	Postoperative hypertension
Microangiopathic hemolytic anemia/disseminated intravascular coagulation	Acute coronary syndrome	Subarachnoid hemorrhage	Acute glomerulonephritis	Postoperative bleeding after surgery
Eclampsia	MI	Intracerebral hemorrhage	Collagen vascular crisis	Severe body burns
Catecholamine excess (drugs, rebound syndrome, pheochromocytoma)	Aortic dissection	Cerebrovascular accident	End-stage renal disease	Severe epistaxis
Vasculitis
Monoamine oxidase inhibitor interactions
Adapted from Vidt DG, Gifford RW. A compendium for the treatment of hypertensive emergencies. Cleve Clin Q 1984;51:421.

TABLE 30-2 Initial Evaluation of Hypertensive Crisis in the Intensive Care Unit

1. Continuous BP monitoring

Direct (intra-arterial) preferred or indirect (cuff)

2. Brief initial evaluation—history and physical examination with attention to

Neurologic including fundoscopic exam, cardiac, and pulmonary system
Assessment of organ perfusion and function (e.g., mental status, heart failure, urine output)

3. Blood and urine studies: electrolytes, blood urea nitrogen (BUN), creatinine, complete blood count (CBC) with differential, urinalysis with sediment; if indicated, serum catecholamines and cardiac enzymes

4. ECG (examine for LV strain or ischemia)

5. Chest radiograph (assess for size of aorta, cardiomegaly, pulmonary edema)

6. Initiation of therapy (within 1 h of presentation for hypertensive emergencies)

7. Further evaluation of etiology once BP is stabilized

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