What are the treatment guidelines for hypertensive (high blood pressure) urgency vs emergency?

Hypertensive Urgency vs Emergency: Definitions and Treatment Guidelines

Critical Distinction

The fundamental difference between hypertensive urgency and emergency is the presence or absence of acute target organ damage, not the absolute blood pressure number. 1

Definitions

Hypertensive Emergency

• Blood pressure >180/120 mmHg WITH evidence of new or worsening target organ damage 1, 2
• The actual BP level may be less important than the rate of BP rise; patients with chronic hypertension often tolerate higher levels than previously normotensive individuals 1
• Untreated 1-year mortality rate exceeds 79% with median survival of only 10.4 months 1, 2

Hypertensive Urgency

• Severe BP elevation (>180/120 mmHg) in otherwise stable patients WITHOUT acute or impending target organ damage 1
• No clinical or laboratory evidence of acute end-organ injury 1
• Often occurs in patients who have withdrawn from or are noncompliant with antihypertensive therapy 1

Target Organ Damage Examples

Target organ damage defining a hypertensive emergency includes: 1, 2

• Neurologic: Hypertensive encephalopathy, intracranial hemorrhage, acute ischemic stroke
• Cardiac: Acute myocardial infarction, acute left ventricular failure with pulmonary edema, unstable angina
• Vascular: Aortic dissection
• Renal: Acute renal failure, thrombotic microangiopathy
• Obstetric: Eclampsia or severe preeclampsia

Management Approach

Hypertensive Emergency Management

Patients with hypertensive emergencies require immediate ICU admission with continuous BP monitoring and parenteral antihypertensive therapy. 1, 2

BP Reduction Targets (varies by clinical scenario):

For patients WITH compelling conditions (aortic dissection, severe preeclampsia/eclampsia, pheochromocytoma): 1

• Reduce SBP to <140 mmHg during the first hour
• For aortic dissection specifically: reduce SBP to <120 mmHg within the first hour 1

For patients WITHOUT compelling conditions: 1

• Reduce SBP by no more than 25% within the first hour
• Then, if stable, reduce to 160/100 mmHg within the next 2-6 hours
• Then cautiously reduce to normal during the following 24-48 hours

Alternative European guideline approach: 1

• Reduce mean arterial pressure (MAP) by 20-25% over several hours for most hypertensive emergencies
• Specific conditions require different targets (see condition-specific section below)

First-Line IV Medications:

Labetalol and nicardipine are the preferred first-line agents for most hypertensive emergencies. 1

• Nicardipine: Initial 5 mg/hr, increase every 5 minutes by 2.5 mg/hr to maximum 15 mg/hr 1, 3
• Labetalol: First-line for malignant hypertension, hypertensive encephalopathy, and most stroke presentations 1
• Clevidipine: Initial 1-2 mg/hr, doubling every 90 seconds until BP approaches target 1
• Sodium nitroprusside: Initial 0.3-0.5 mcg/kg/min, but use with extreme caution due to cyanide toxicity risk 1

Condition-Specific Targets:

• Acute aortic dissection: SBP <120 mmHg and heart rate <60 bpm immediately; use esmolol plus nitroprusside or labetalol 1
• Acute pulmonary edema: SBP <140 mmHg immediately; use nitroprusside or nitroglycerin with loop diuretic 1
• Acute coronary syndrome: SBP <140 mmHg immediately; use nitroglycerin as first-line 1
• Acute ischemic stroke with BP >220/120 mmHg: Reduce MAP by 15% over 1 hour 1
• Acute hemorrhagic stroke with SBP >180 mmHg: Target systolic 130-180 mmHg immediately 1
• Malignant hypertension/hypertensive encephalopathy: Reduce MAP by 20-25% over several hours 1

Hypertensive Urgency Management

Patients with hypertensive urgency should NOT be referred to the emergency department, do not require immediate BP reduction in the ED, and do not require hospitalization. 1

• Treat by reinstitution or intensification of oral antihypertensive drug therapy 1
• Address anxiety if applicable 1
• Oral agents such as captopril, labetalol, or nifedipine retard (extended-release) can be used 1
• Avoid short-acting nifedipine due to unpredictable rapid BP falls and reflex tachycardia 1, 4, 5
• Observe for at least 2 hours after medication administration to evaluate efficacy and safety 1
• Controlled BP reduction to safer levels without risk of hypotension is the goal 1

Critical Pitfalls to Avoid

• Never use oral therapy for hypertensive emergencies 1
• Avoid excessive BP reduction that may precipitate renal, cerebral, or coronary ischemia 1, 2
• Do not use immediate-release nifedipine for any hypertensive crisis 1, 4, 5
• Avoid sodium nitroprusside when possible due to cyanide toxicity risk; if used, keep duration <30 minutes and dose <4 mcg/kg/min 1, 4, 5
• Do not treat hypertensive urgency as an emergency—rapid BP lowering can cause cardiovascular complications 1
• In acute ischemic stroke, generally avoid BP lowering unless BP exceeds 220/120 mmHg 1, 2

Diagnostic Workup for Hypertensive Emergency

Essential laboratory tests include: 1, 2

• Complete blood count (hemoglobin, platelets)
• Creatinine, sodium, potassium
• Lactate dehydrogenase (LDH) and haptoglobin (to detect hemolysis)
• Urinalysis for protein and urine sediment
• Troponins if chest pain present
• ECG
• Fundoscopy

Additional imaging based on presentation: 1, 2

• Chest X-ray for pulmonary edema
• Echocardiogram for cardiac function
• CT/MRI brain for neurologic symptoms
• CT-angiography for suspected aortic dissection

Screen for secondary hypertension after stabilization, as 20-40% of patients with malignant hypertension have an underlying secondary cause. 1, 2