How should an adult patient with no prior history of hypertension and presenting with hypertension be managed in the emergency room?

Management of Hypertension in the Emergency Department

For an adult presenting to the ED with newly discovered hypertension and no prior history, the critical first step is determining whether acute target organ damage is present—this distinction alone determines whether immediate IV therapy in the ICU is required versus oral medications with outpatient follow-up. 1

Immediate Assessment: Hypertensive Emergency vs. Urgency

The presence or absence of acute target organ damage—not the blood pressure number itself—is the sole deciding factor in ED management. 1, 2

Define the Clinical Scenario

Hypertensive Emergency (requires ICU admission):

• BP >180/120 mmHg WITH evidence of acute target organ damage 1, 2
• 1-year mortality >79% if untreated 1
• Requires immediate IV therapy 1

Hypertensive Urgency (outpatient management):

• BP >180/120 mmHg WITHOUT acute target organ damage 1, 2
• Managed with oral medications and follow-up within 2-4 weeks 2
• Hospitalization NOT required 3

Assess for Target Organ Damage

Perform focused evaluation for:

Neurologic:

• Altered mental status, somnolence, lethargy (hypertensive encephalopathy) 1
• Headache with vomiting, visual disturbances, seizures 1
• Focal neurologic deficits suggesting stroke 1

Cardiac:

• Chest pain suggesting acute myocardial ischemia/infarction 1
• Acute pulmonary edema with dyspnea 1
• Signs of acute heart failure 1

Renal:

• Acute deterioration in renal function 1
• Oliguria or signs of acute kidney injury 1

Ophthalmologic:

• Fundoscopy for bilateral retinal hemorrhages, cotton wool spots, or papilledema (malignant hypertension) 1
• Note: isolated subconjunctival hemorrhage is NOT target organ damage 1

Vascular:

• Signs/symptoms of aortic dissection 1

Laboratory screening:

• CBC, creatinine, electrolytes, LDH, haptoglobin, urinalysis, troponins (if chest pain) 1
• ECG to assess for ischemia or left ventricular hypertrophy 1

Management Algorithm

If Target Organ Damage Present: Hypertensive Emergency

Immediate actions:

• Admit to ICU with continuous arterial line BP monitoring (Class I recommendation) 1, 2
• Initiate IV antihypertensive therapy immediately 1

Blood pressure targets:

• Standard approach: Reduce mean arterial pressure by 20-25% within the first hour, then if stable reduce to 160/100 mmHg over 2-6 hours, then cautiously normalize over 24-48 hours 1, 2
• Compelling conditions requiring more aggressive targets:
  • Aortic dissection: SBP <120 mmHg within 20 minutes 1, 2
  • Acute coronary syndrome/pulmonary edema: SBP <140 mmHg immediately 1
  • Severe preeclampsia/eclampsia: SBP <140 mmHg within first hour 2

Critical pitfall: Avoid excessive acute drops >70 mmHg systolic, as this precipitates cerebral, renal, or coronary ischemia, particularly in patients with chronic hypertension who have altered autoregulation. 1

First-line IV medications:

Nicardipine (preferred for most emergencies):

• Dose: 5 mg/hr IV, titrate by 2.5 mg/hr every 15 minutes, maximum 15 mg/hr 1, 2
• Onset: 5-10 minutes 2
• Advantages: Maintains cerebral blood flow, predictable titration 1
• Avoid as monotherapy in acute coronary syndrome (causes reflex tachycardia) 1

Labetalol (preferred for encephalopathy, eclampsia, aortic dissection):

• Dose: 10-20 mg IV bolus over 1-2 minutes, repeat/double every 10 minutes, maximum cumulative 300 mg 1, 2
• Alternative: 2-8 mg/min continuous infusion 1
• Onset: 5-10 minutes, duration 3-6 hours 1
• Contraindications: reactive airway disease, COPD, heart block, bradycardia, decompensated heart failure 1, 4

Condition-specific selections:

• Acute coronary syndrome/pulmonary edema: Nitroglycerin IV 5-100 mcg/min, often combined with labetalol 1
• Aortic dissection: Esmolol plus nitroprusside/nitroglycerin (beta blockade must precede vasodilator to prevent reflex tachycardia) 1
• Eclampsia/preeclampsia: Hydralazine, labetalol, or nicardipine (ACE inhibitors, ARBs, nitroprusside absolutely contraindicated) 1
• Hypertensive encephalopathy: Nicardipine preferred (preserves cerebral blood flow) or labetalol 1

Medications to avoid:

• Immediate-release nifedipine (unpredictable precipitous drops, reflex tachycardia) 1
• Sodium nitroprusside except as last resort (cyanide toxicity risk) 1, 4
• Hydralazine as first-line (unpredictable response, prolonged duration) 1

If NO Target Organ Damage: Hypertensive Urgency

Key evidence: Up to one-third of patients with diastolic BP >95 mmHg normalize before arranged follow-up, and rapidly lowering BP in asymptomatic patients may be harmful (Level B recommendation). 3

Management approach:

• Do NOT admit to hospital 2
• Do NOT use IV medications 3
• Initiate or adjust oral antihypertensive therapy 2
• Arrange outpatient follow-up within 2-4 weeks 2
• Target BP <130/80 mmHg (or <140/90 mmHg in elderly/frail), achieve within 3 months 1

Oral medication selection:

For non-Black patients:

• Start low-dose ACE inhibitor or ARB 1
• Add dihydropyridine calcium channel blocker if needed 1
• Add thiazide/thiazide-like diuretic as third-line 1

For Black patients:

• Start ARB plus dihydropyridine calcium channel blocker OR calcium channel blocker plus thiazide diuretic 1
• Add missing component as third-line 1

Critical pitfall: Patients can be discharged even if BP remains >180/110 mmHg IF there is no evidence of acute target organ damage and oral therapy is initiated. 1

Post-Stabilization Management (After Hypertensive Emergency)

• Screen for secondary hypertension (present in 20-40% of malignant hypertension cases): renal artery stenosis, pheochromocytoma, primary aldosteronism 1
• Address medication non-adherence (most common trigger) 1
• Transition to oral combination therapy: RAS blockers, calcium channel blockers, diuretics 1
• Frequent follow-up (at least monthly) until target BP reached and organ damage regressed 1

Common Clinical Pitfalls

1. Do not treat the BP number alone without assessing for true hypertensive emergency—many patients with acute pain or distress have transiently elevated BP that normalizes when the underlying condition is treated. 1

2. Do not rapidly lower BP in hypertensive urgency—this may cause cerebral, renal, or coronary ischemia in patients with chronic hypertension who have altered autoregulation. 1

3. Do not normalize BP acutely in hypertensive emergencies—the rate of BP rise is more important than the absolute value, and patients with chronic hypertension cannot tolerate acute normalization. 1

4. Do not initiate treatment for asymptomatic hypertension in the ED when patients have follow-up—this is unnecessary and may be harmful (Level B recommendation). 3

5. Do not overlook subtle signs of organ damage in asymptomatic patients with severely elevated BP—perform brief neurologic exam, cardiac assessment, and fundoscopic exam. 1