Hypertensive emergencies

Hypertensive encephalopathy

Acute ischemic stroke

Acute intracerebral hemorrhage

Aortic dissection

Unstable angina/acute myocardial infarction

Acute pulmonary edema

Preeclampsia/HELLP syndrome/eclampsia

Acute renal failure

Diagnosis and evaluation

History
- Ask for symptoms related to specific organ dysfunction:
  - Neurological symptoms: headache, altered mental status, visual changes.
  - Cardiovascular symptoms: chest pain, dyspnea.
  - Renal failure: oliguria, anuria, altered mental status, symptoms related to electrolyte abnormalities.
Elements of the past medical history, including coronary artery disease, prior cerebrovascular events, and renal disease should be obtained.
Patients should also be asked about current prescription medications for blood pressure control, as well as recent changes in their medications or dose.
Always consider pregnancy as a possible etiology for hypertensive symptoms in women of childbearing age.
Investigate potential use of recreational drugs such as cocaine, amphetamines, or phencyclidine.
Physical examination
- Confirm blood pressure measurement using an appropriately sized cuff.
- If there is a concern for aortic dissection, the blood pressure should be taken in both upper extremities and compared for discrepancies.
- An elevated temperature may suggest thyrotoxicosis or an underlying infection.
- Tachypnea and hypoxia may suggest an underlying pulmonary dysfunction or acute pulmonary edema.
- Clinical signs of congestive heart failure such as elevated jugular venous pressure, a third heart sound, or rales may be present as well.
- The fundoscopic examination evaluating for arteriolar changes may reveal papilledema, retinal hemorrhage, and exudates.
- A full neurological examination should be performed to assess for mental status changes, focal neurological deficits, and visual changes.
Laboratory tests and imaging
- Complete blood count and peripheral smear to assess for hemolysis and microangiopathic anemia.
- Complete serum chemistry panel to assess for renal function and presence of electrolyte derangements.
- Liver panel, particularly in pregnant patients, to help rule out the HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count.)
- Urinalysis with microscopic examination of the urine for presence of proteinuria, red blood cells, and/or casts.
- Electrocardiogram (ECG) to look for signs of ischemia or left ventricular hypertrophy.
- For patients with dyspnea or chest pain, a chest radiograph (CXR) may demonstrate pulmonary edema or mediastinal widening.
- A computed tomography (CT) of the chest has higher sensitivity and specificity than CXR and may provide additional information if aortic dissection is suspected.
- For patients presenting with a headache, changes in mental status, or abnormal neurological findings, a non-contrast CT of the brain should be performed to rule out an acute intracerebral hemorrhage.
- An MRI may be needed to identify an ischemic stroke and should be ordered in consultation with a neurologist.

Critical management

Critical management will depend on the presence of end-organ damage. Only patients with a diagnosis of hypertensive emergency will require immediate interventions in the emergency department for blood pressure lowering.
Patients with chronically elevated blood pressure may suffer detrimental consequences if their blood pressure is lowered too quickly. Dramatic and rapid decreases in blood pressure can result in critical hypoperfusion of the brain, heart, and kidneys, resulting in ischemia or infarction.
Patients with hypertensive urgency can be managed as outpatients as long as reliable follow-up can be arranged. They are usually started on oral antihypertensives with a goal of lowering their blood pressure to less than 160/100 mmHg over 12–48 hours.
Admission may be considered for patients with multiple medical problems, or those without access to follow-up care.
If there is evidence of end-organ dysfunction on history, physical examination, or laboratory evaluation, the diagnosis of hypertensive emergency is made.
Correction of blood pressure in a hypertensive emergency should be via continuous infusion of medications that have a rapid onset and are both short-acting and titratable.
The immediate goal is to reduce the mean arterial pressure (MAP) by no more than 20–25%, or to reduce the diastolic blood pressure to 100–110 mmHg within 2–6 hours. There are certain exceptions, however, and these are detailed in the “Special considerations” section below.
Agents should be chosen based on the specific organ(s) being damaged (Tables 27.2 and 27.3).