Hypertensive Urgencies & Emergencies

Essentials of Diagnosis

• Hypertensive crisis is typically defined as systolic blood pressure (BP) > 220 mm Hg or diastolic BP > 125 mm Hg

• However, the development of acute end organ damage depends on

  • Rate of rise in BP

  • Magnitude of increase in BP

  • Presence of underlying conditions

General Considerations

• Hypertensive urgency usually has systolic BP > 220 mm Hg or diastolic BP > 125 mm Hg without evidence of acute end-organ damage

• Hypertensive emergency defined as acute hypertensive injury to heart, brain, retina, kidneys, aorta and/or eclampsia

• Encephalopathy or nephropathy accompanying hypertensive retinopathy has historically been termed malignant hypertension, but the therapeutic approach is identical to that used in other hypertensive emergencies

Demographics

• Occurs in any age, gender, or racial/ethnic group

• Usually occurs in people with preexisting hypertension

• Often due to abrupt cessation of antihypertensive therapy

• Also occurs in setting of acute kidney injury or use of high doses of sympathomimetics

Symptoms and Signs

• Symptoms depend on the end organ involved

• Headaches, irritability, confusion, and somnolence are signs of encephalopathy

• Chest pain or dyspnea occurs with cardiopulmonary involvement

• Back pain occurs with aortic dissection

• Blurry or diminished vision occurs with retinal involvement

• Cardiac examination may reveal low A2, an S4, or a murmur of aortic regurgitation

• Papilledema is indicative of elevated intracranial pressure

• Crackles on lung examination occur with heart failure

Differential Diagnosis

• Any of the many causes of hypertension can lead to severe hypertension (see Hypertension, Chronic)

• The underlying causes most likely to present in this way include

  • Poorly controlled or undiagnosed hypertension

  • Withdrawal from antihypertensive medications

  • Chronic kidney disease

  • Renal artery stenosis (atherosclerotic or fibromuscular dysplasia)

  • Sympathomimetic drug use

  • Scleroderma crisis

  • Pheochromocytoma

Laboratory Tests

• Complete blood count (microangiopathic smear with thrombocytopenia due to platelet consumption)

• Urinalysis

• Serum creatinine, blood urea nitrogen, troponin, creatine kinase

• ECG

• Chest radiograph

• Consider urine screen for cocaine

Diagnostic Procedures

• If CNS symptoms, head CT to rule out bleed/infarct

• If chest pain, ECG (to rule out coronary syndrome), chest radiograph (thoracic aortic dissection)

• If kidney dysfunction, renal ultrasound to rule out obstruction or chronic kidney disease

Medications

Hypertensive urgency

• Goal is to relieve symptoms and bring BP to reasonable level within 24–48 hours, aiming for gradual attainment of optimal control over several weeks

• Effective oral agents are clonidine, captopril, and slow-release nifedipine

• Avoid beta-blockers if cocaine use

• Avoid angiotensin-converting enzyme (ACE) inhibitors if renal artery stenosis suspected

• Avoid short-acting dihydropyridine calcium channel blockers because BP reduction is often precipitous

Hypertensive emergency

• Treatment goal is to reduce mean arterial pressure by 25% in 1–2 h; then to reduce BP to 160/100 mm Hg over next 6–12 h

• If ischemic stroke, only treat if systolic BP exceeds 180–200 mm Hg; aim to reduce by only 10–15%

• If thrombolytic agents are to be used to treat ischemic stroke, target BP is < 185/110 mm Hg

• Avoid excessive reduction in BP because this can lead to coronary, cerebral, or renal hypoperfusion

• Key to pharmacologic therapy is to use an agent with predictable, dose-dependent, transient effect

• Sodium nitroprusside is no longer the treatment of choice

• In most situations, appropriate BP control is best achieved by using combinations of nicardipine or clevidipine, labetolol and esmolol

• Fenoldopam, a peripheral dopamine agonist, is also effective

• ACE inhibitors are specifically indicated in scleroderma crisis

Therapeutic Procedures

• Treatment algorithm differs for hypertensive urgency and hypertensive emergency

• Goal is similar: reduce BP to "safe" range without causing end-organ damage

• Table 11–15 summarizes treatment by primary site of end organ damage and Table 11–16 lists treatment options for hypertensive emergencies and urgencies

• In women who are pregnant or of child-bearing age, preeclampsia or eclampsia should be excluded; if diagnosed, proper management plans should be instituted promptly

Follow-Up

• Patients with hypertensive urgency whose BP is brought under control should be seen within 48–72 h for a recheck of BP and tolerability of the antihypertensive regimen

• Patients with hypertensive emergency, once discharged from the hospital, should be followed-up in 48–72 h to ensure good compliance with BP medication and adequate BP control

Complications

• Stroke

• Myocardial infarction

• Heart failure

• Retinal vasculopathy

• Aortic dissection

• Acute kidney injury

When to Refer

• Refer patients with hypertensive urgency or emergency to expert in management of severe hypertension

• Hypertensive crises in pregnancy must be managed by expert in high-risk obstetrics

When to Admit

• Hospitalization for hypertensive urgency rarely needed

• Hospitalize all patients with hypertensive emergency, in particular patients with following

  • Encephalopathy

  • Neurologic deficits

  • Chest pain

  • Dyspnea

  • Papilledema

  • Hematuria

  • Kidney dysfunction

  • ECG changes

  • Eclampsia

• Usually such patients need ICU admission for close monitoring of BP and clinical symptoms and signs