Guidelines for Hypertensive Urgency, Hypertensive Emergency, and White-Coat Hypertension
Hypertensive Emergency vs. Hypertensive Urgency
The critical distinction is the presence or absence of acute target-organ damage, not the absolute blood pressure number. 1
Hypertensive Emergency
- Defined as blood pressure ≥180/120 mmHg WITH acute target-organ damage requiring immediate intervention and ICU admission. 2, 1
- Target-organ damage includes:
- Neurologic: hypertensive encephalopathy, intracranial hemorrhage, acute ischemic stroke, altered mental status, seizures 1
- Cardiac: acute myocardial infarction, unstable angina, acute left ventricular failure with pulmonary edema 1
- Vascular: aortic dissection or aneurysm 1
- Renal: acute kidney injury, thrombotic microangiopathy 1
- Ophthalmologic: bilateral retinal hemorrhages, cotton-wool spots, papilledema (malignant hypertension) 1
- Obstetric: severe preeclampsia or eclampsia 1
- Without treatment, carries a 1-year mortality >79% and median survival of only 10.4 months. 1
Hypertensive Urgency
- Defined as blood pressure ≥180/120 mmHg WITHOUT acute target-organ damage. 1, 3
- Can be managed with oral medications and outpatient follow-up; hospitalization is NOT required. 1, 4
- Up to one-third of patients with elevated blood pressure normalize before follow-up, and rapid lowering may be harmful. 1
Management of Hypertensive Emergency
Blood Pressure Reduction Targets
For patients WITHOUT compelling conditions:
- Reduce mean arterial pressure by 20-25% (or systolic BP by ≤25%) within the first hour 1
- Then reduce to ≤160/100 mmHg over 2-6 hours if stable 1
- Cautiously normalize over 24-48 hours 1
- Avoid systolic drops >70 mmHg as this precipitates cerebral, renal, or coronary ischemia, especially in chronic hypertensives with altered autoregulation 1
For patients WITH compelling conditions:
- Aortic dissection: SBP <120 mmHg within 20 minutes 1
- Severe preeclampsia/eclampsia or pheochromocytoma: SBP <140 mmHg within first hour 1
- Acute coronary syndrome or pulmonary edema: SBP <140 mmHg immediately 1
- Acute hemorrhagic stroke with SBP ≥220 mmHg: carefully lower to <180 mmHg 2
- Acute ischemic stroke with BP >220/120 mmHg: reduce MAP by approximately 15% over first hour 2
First-Line Intravenous Medications
Nicardipine (preferred for most emergencies except acute heart failure):
- Start 5 mg/hr IV infusion, titrate by 2.5 mg/hr every 15 minutes to maximum 15 mg/hr 1
- Preserves cerebral blood flow and does not increase intracranial pressure 1
- Onset 5-15 minutes, duration 30-40 minutes 1
Labetalol (preferred for aortic dissection, eclampsia, malignant hypertension with renal involvement):
- 10-20 mg IV bolus over 1-2 minutes, repeat/double every 10 minutes (max cumulative 300 mg) 1
- OR continuous infusion 2-8 mg/min 1
- Contraindicated in reactive airway disease, COPD, heart block, bradycardia, decompensated heart failure 1
Clevidipine (alternative rapid-acting calcium channel blocker):
- Start 1-2 mg/hr IV infusion, double every 90 seconds until near target, then increase <2-fold every 5-10 minutes 1
- Maximum 32 mg/hr 1
Sodium nitroprusside (last-resort only):
- 0.25-10 µg/kg/min IV infusion 1
- Risk of cyanide toxicity with prolonged use (>48-72 hours) or renal insufficiency 1
Condition-Specific Regimens
- Acute coronary syndrome/pulmonary edema: IV nitroglycerin 5-100 µg/min ± labetalol; avoid nicardipine monotherapy due to reflex tachycardia 1
- Aortic dissection: Esmolol loading 500-1000 µg/kg, then 50-200 µg/kg/min BEFORE any vasodilator (nitroprusside or nitroglycerin) 1
- Eclampsia/preeclampsia: Labetalol, hydralazine, or nicardipine; ACE inhibitors, ARBs, and nitroprusside are absolutely contraindicated 1
- Hypertensive encephalopathy: Nicardipine preferred (preserves cerebral blood flow); labetalol acceptable alternative 1
Management of Hypertensive Urgency
Blood Pressure Reduction Strategy
- Gradual reduction over 24-48 hours to <160/100 mmHg 1, 4
- Do NOT rapidly lower blood pressure as this may cause cerebral, renal, or coronary ischemia in chronic hypertensives 1
Preferred Oral Agents
- Captopril 12.5-25 mg PO (caution in volume-depleted patients) 1
- Extended-release nifedipine 30-60 mg PO 1
- Labetalol 200-400 mg PO (avoid in reactive airway disease, heart block, bradycardia) 1
- NEVER use immediate-release nifedipine due to unpredictable precipitous drops, stroke, and death 1
Follow-Up
- Arrange outpatient follow-up within 2-4 weeks 2, 1
- Target BP <130/80 mmHg (or <140/90 mmHg in elderly/frail) within 3 months 1
White-Coat Hypertension (Newer Terminology)
White-coat hypertension is now defined using ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) as:
- Office BP ≥130/80 mmHg but out-of-office (home or daytime ambulatory) BP <130/80 mmHg after 3 months of diet and lifestyle modification 2
- Should be considered in drug-naïve individuals with office BP 130-159/80-99 mmHg 2
Diagnostic Confirmation
- ABPM or HBPM should be used to confirm the diagnosis and detect white-coat hypertension versus masked hypertension 2
- White-coat hypertension is associated with CVD risk approximating that of normal BP 2
- Prevalence is approximately 20% among mild hypertensives and increases with age 5
Corresponding BP Values
The ACC/AHA provides equivalent values for office and out-of-office measurements: 2
- Office 130/80 mmHg = Home 130/80 mmHg = Daytime ambulatory 130/80 mmHg
- Office 140/90 mmHg = Home 135/85 mmHg = Daytime ambulatory 135/85 mmHg
Management
- Patients with white-coat hypertension and high cardiovascular risk or proven target-organ damage should be pharmacologically treated 6
- Uncomplicated white-coat hypertension does NOT require immediate medication but warrants close follow-up with regular assessment of risk factors and BP monitoring every 6 months (office) and every 1-2 years (ambulatory) 6
Post-Stabilization and Long-Term Management
- Screen for secondary causes as 20-40% of malignant hypertension cases have identifiable etiologies (renal artery stenosis, pheochromocytoma, primary aldosteronism, renal parenchymal disease) 1
- Address medication non-adherence, the most common trigger for hypertensive emergencies 1
- Monthly follow-up until target BP achieved and organ damage regressed 1
- Transition to oral regimen combining renin-angiotensin system blocker, calcium channel blocker, and diuretic 1
Critical Pitfalls to Avoid
- Do NOT admit asymptomatic patients with severe hypertension without target-organ damage (urgency, not emergency) 1
- Do NOT use oral agents for hypertensive emergencies; IV therapy is mandatory 1
- Do NOT use immediate-release nifedipine due to risk of precipitous BP fall, stroke, and death 1
- Do NOT rapidly lower BP in hypertensive urgency; gradual reduction is essential 1
- Do NOT normalize BP acutely in chronic hypertensives; altered autoregulation predisposes to ischemic injury 1