Hypertensive emergency

What it is

Severe hypertension is a blood pressure over 180 mm Hg systolic or over 110 mm Hg diastolic. Severe hypertension with end-organ damage constitutes a hypertensive emergency. The same readings without signs or symptoms of acute target organ injury are known as severe asymptomatic hypertension in one source; the national guideline calls this hypertensive urgency, defined as SBP >=180 mmHg and/or DBP >=110 mmHg without HMOD. The first step in the management of severe hypertension is determining whether a hypertensive emergency is present.

How it presents

Hypertensive emergency takes six forms, each with its own findings on history, physical examination and initial investigations:

• Hypertensive encephalopathy: altered mental status, headache, seizures, visual disturbance, nausea, vomiting and papilledema.
• Intracranial haemorrhage: severe headache, dizziness, confusion, slurred speech, seizures, body side weakness or numbness, or other focal neurologic deficits.
• Acute pulmonary edema: SOB, chest pain or pressure, orthopnoea and haemoptysis, with inspiratory crackles on lung exam and a chest x-ray that shows cardiomegaly and signs of pulmonary edema.
• Acute coronary syndrome: chest pain, SOB, elevated troponin and CK-MB, and an ECG with ischemic changes.
• Aortic dissection: severe chest and/or back pain, often of a tearing quality, unequal pulses, a blood pressure difference of more than 20 mmHg between arms, a new aortic insufficiency murmur, and a chest x-ray with a wide mediastinum.
• Acute renal failure: decreased urine output, that is oliguria or anuria, SOB, hematuria, peripheral edema, urinalysis positive for protein and RBCs with or without casts, and acutely elevated urea and creatinine.