What are the diagnostic criteria and recommended management for hypertensive emergency versus hypertensive urgency?

Hypertensive Crisis: Diagnostic Criteria and Management

Definition and Critical Distinction

Hypertensive emergency is defined by blood pressure >180/120 mmHg WITH acute target-organ damage, whereas hypertensive urgency has the same pressure elevation WITHOUT organ injury—the presence of organ damage, not the absolute BP number, determines management. 1

• The rate of BP rise may be more clinically important than the absolute value; patients with chronic hypertension often tolerate higher pressures than previously normotensive individuals 1
• Untreated hypertensive emergencies carry a 1-year mortality >79% and median survival of only 10.4 months 1

Rapid Bedside Assessment for Target-Organ Damage

Within minutes of presentation, perform a focused evaluation to identify acute organ injury:

Neurologic Assessment

• Altered mental status, severe headache with vomiting, visual disturbances, seizures, or focal deficits suggest hypertensive encephalopathy or stroke 1, 2
• Somnolence or lethargy may precede seizures and coma 1

Cardiac Evaluation

• Chest pain or dyspnea with pulmonary edema indicates acute coronary syndrome, aortic dissection, or left-ventricular failure 1, 2
• Obtain ECG and troponin for all patients with chest pain 1

Ophthalmologic Examination

• Fundoscopy is mandatory—bilateral retinal hemorrhages, cotton-wool spots, or papilledema (grade III-IV retinopathy) define malignant hypertension 1, 3
• Isolated subconjunctival hemorrhage is NOT acute target-organ damage 1

Renal Assessment

• Acute rise in creatinine, oliguria, or new proteinuria indicates renal injury 1, 3
• Check hemoglobin, platelets, LDH, and haptoglobin to detect thrombotic microangiopathy 1

Vascular Evaluation

• Sudden severe chest or back pain radiating posteriorly raises suspicion for aortic dissection 1
• Consider CT angiography if dissection is suspected 3

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Management of Hypertensive Emergency

Admit immediately to ICU with continuous arterial-line monitoring (Class I recommendation). 1

Blood-Pressure Reduction Targets

Standard Approach (No Compelling Conditions)

• First hour: Reduce mean arterial pressure by 20–25% (or systolic ≤25%) 1, 3
• Hours 2–6: Lower to ≤160/100 mmHg if stable 1, 3
• Hours 24–48: Gradually normalize BP 1, 3
• Avoid systolic drops >70 mmHg—this can precipitate cerebral, renal, or coronary ischemia in chronic hypertensives with altered autoregulation 1, 3

Condition-Specific Targets

Condition	Target BP	Timeframe
Aortic dissection	SBP <120 mmHg	Within 20 minutes [1,3]
Severe preeclampsia/eclampsia	SBP <140 mmHg	Within first hour [1,3]
Acute coronary syndrome or pulmonary edema	SBP <140 mmHg	Immediately [1,3]
Acute intracerebral hemorrhage (SBP ≥220)	SBP 140–180 mmHg	Within 6 hours [1]
Acute ischemic stroke (BP >220/120)	Reduce MAP by 15%	Within 1 hour [1,3]

First-Line Intravenous Medications

Nicardipine (Preferred for Most Emergencies)

• Start 5 mg/h IV, titrate by 2.5 mg/h every 15 minutes, maximum 15 mg/h 1, 3
• Preserves cerebral blood flow, does not raise intracranial pressure, allows predictable titration 1
• Onset 5–15 minutes, duration 30–40 minutes 1
• Avoid in acute heart failure due to reflex tachycardia 1

Labetalol (Preferred for Aortic Dissection, Eclampsia, Renal Involvement)

• 10–20 mg IV bolus over 1–2 minutes, repeat/double every 10 minutes (max cumulative 300 mg) 1, 3
• Alternative: continuous infusion 2–8 mg/min 1
• Contraindicated in reactive airway disease, COPD, heart block, bradycardia, decompensated heart failure 1, 3

Clevidipine (Alternative Rapid-Acting CCB)

• Start 1–2 mg/h, double every 90 seconds until near target, then increase <2-fold every 5–10 minutes; max 32 mg/h 1
• Contraindicated in soy/egg allergy 1

Sodium Nitroprusside (Last Resort Only)

• 0.25–10 µg/kg/min IV infusion 1
• Requires thiosulfate co-administration when ≥4 µg/kg/min or >30 minutes to prevent cyanide toxicity 1
• Avoid in renal insufficiency 1

Condition-Specific Regimens

Acute Coronary Syndrome / Pulmonary Edema

• Nitroglycerin IV 5–100 µg/min ± labetalol 1, 3
• Avoid nicardipine monotherapy—reflex tachycardia worsens ischemia 1

Aortic Dissection

• Esmolol loading 500–1000 µg/kg, then 50–200 µg/kg/min BEFORE any vasodilator 1, 3
• Add nitroprusside or nitroglycerin to achieve SBP ≤120 mmHg and HR <60 bpm 1, 3

Eclampsia / Severe Preeclampsia

• Labetalol, hydralazine, or nicardipine 1, 3
• ACE inhibitors, ARBs, and nitroprusside are absolutely contraindicated 1, 3

Hypertensive Encephalopathy

• Nicardipine is superior—preserves cerebral perfusion without raising intracranial pressure 1
• Labetalol is an acceptable alternative 1

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Management of Hypertensive Urgency

Hospitalization is NOT required; manage with oral agents and outpatient follow-up within 2–4 weeks. 1, 4

Blood-Pressure Reduction Strategy

• Gradual reduction to <160/100 mmHg over 24–48 hours 1, 4
• Then aim for <130/80 mmHg over subsequent weeks 1, 4
• Rapid lowering is discouraged—can precipitate cerebral, renal, or coronary ischemia in chronic hypertensives 1, 4

Preferred Oral Agents

• Extended-release nifedipine 30–60 mg PO 1, 4
• Captopril 12.5–25 mg PO (caution in volume-depleted patients) 1, 4
• Labetalol 200–400 mg PO (avoid in reactive airway disease, heart block, bradycardia) 1, 4

Follow-Up

• Arrange outpatient visit within 2–4 weeks 1, 4
• Observe patient for at least 2 hours after medication administration 4
• Monthly visits until target BP <130/80 mmHg is achieved 1, 4

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Critical Pitfalls to Avoid

• Do not admit patients with severe hypertension WITHOUT evidence of acute target-organ damage—this is urgency, not emergency 1, 4
• Do not use immediate-release nifedipine—causes unpredictable precipitous drops, stroke, and death 1, 4, 3
• Do not use IV medications for hypertensive urgency—oral therapy is safer 1, 4
• Do not rapidly lower BP in urgency—gradual reduction is essential 1, 4
• Do not normalize BP acutely in chronic hypertensives—altered autoregulation predisposes to ischemic injury 1, 4
• Do not use hydralazine as first-line—unpredictable response and prolonged duration 1
• Reserve nitroprusside for last resort—cyanide toxicity risk 1
• Up to one-third of patients with diastolic BP >95 mmHg normalize before follow-up; overly aggressive reduction can be harmful 1

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Post-Stabilization Management

• Screen for secondary causes—20–40% of malignant hypertension cases have identifiable etiologies (renal artery stenosis, pheochromocytoma, primary aldosteronism, renal parenchymal disease) 1, 3
• Address medication non-adherence—the most common trigger for hypertensive emergencies 1, 3
• Transition to oral regimen combining RAS blocker, calcium-channel blocker, and diuretic 1
• Monthly follow-up until target BP achieved and organ damage regressed 1, 4
• Patients with prior emergency remain at markedly increased cardiovascular and renal risk 1, 3