What is the management of hypertensive emergencies?

Management of Hypertensive Emergencies

Hypertensive emergencies require immediate blood pressure reduction with intravenous medications to prevent progressive target organ damage, with labetalol being the first-line treatment for most presentations. 1

Definition and Classification

• Hypertensive Emergency: Severe BP elevation (usually >200/120 mmHg) with evidence of acute target organ damage
• Hypertensive Urgency: Severe BP elevation without acute end-organ damage

Initial Assessment and Monitoring

• Evaluate for target organ damage:

  • Retina: Advanced retinopathy
  • Brain: Encephalopathy, stroke (ischemic or hemorrhagic)
  • Heart: Acute coronary syndrome, pulmonary edema
  • Kidneys: Acute renal failure
  • Blood: Thrombotic microangiopathy

• Continuous monitoring of vital signs every 30 minutes during the first 2 hours is essential 1

• Bradycardia with severe hypertension should raise immediate concern for increased intracranial pressure 1

Treatment Approach

Medication Selection by Clinical Presentation

Clinical Presentation	Time Frame & Target	First-Line Treatment	Alternative Options
Malignant hypertension with/without TMA or acute renal failure	Several hours, MAP -20% to -25%	Labetalol	Nitroprusside, Nicardipine, Urapidil
Hypertensive encephalopathy	Immediate, MAP -20% to -25%	Labetalol	Nitroprusside, Nicardipine
Acute ischemic stroke and BP >220/120 mmHg	1 hour, MAP -15%	Labetalol	Nitroprusside, Nicardipine
Acute ischemic stroke with indication for thrombolysis and BP >185/110 mmHg	1 hour, MAP -15%	Labetalol	Nicardipine, Nitroprusside
Acute hemorrhagic stroke and SBP >180 mmHg	Immediate, SBP 130-180 mmHg	Labetalol	Urapidil, Nicardipine
Acute coronary event	Immediate, SBP <140 mmHg	Nitroglycerin	Urapidil, Labetalol
Acute cardiogenic pulmonary edema	Immediate, SBP <140 mmHg	Nitroprusside or Nitroglycerin (with loop diuretic)	Urapidil (with loop diuretic)
Acute aortic disease	Immediate, SBP <120 mmHg and HR <60 bpm	Esmolol and Nitroprusside or Nitroglycerin	Labetalol or Metoprolol, Nicardipine

Key Medication Administration Guidelines

Nicardipine Administration 2

• Administer by slow continuous infusion via central line or large peripheral vein
• Dilute 25 mg in 240 mL of compatible IV fluid (concentration 0.1 mg/mL)
• Compatible with: Dextrose 5%, Normal saline, combinations of these
• Not compatible with: Sodium bicarbonate 5% or Lactated Ringer's
• Initial dose: 5 mg/hr
• Titration: Increase by 2.5 mg/hr every 15 minutes (or every 5 minutes for more rapid reduction)
• Maximum dose: 15 mg/hr
• Change infusion site every 12 hours if using peripheral vein

Clevidipine Administration 3

• Available as 0.5 mg/mL sterile emulsion in single-use vials
• No dilution required
• Photosensitive - store in cartons until use
• Once stopper is punctured, use within 12 hours
• Dose is titratable based on blood pressure response

Important Principles

1. Blood Pressure Reduction Rate:

   • Avoid acute reduction in systolic BP >70 mmHg from initial levels within 1 hour 1
   • Target 20-25% reduction in mean arterial pressure in most emergencies

2. Medication Selection Considerations:

   • Avoid sodium nitroprusside when possible due to toxicity 4
   • Avoid immediate-release nifedipine, nitroglycerin, and hydralazine as first-line agents due to significant toxicities and adverse effects 4

3. Special Populations:

   • For patients with volume overload, consider ultrafiltration and IV loop diuretics 1
   • For patients with renal impairment, monitor closely when titrating medications 2

4. Transition to Oral Therapy:

   • When switching to oral nicardipine, administer first dose 1 hour prior to discontinuing infusion 2
   • For other oral agents, initiate upon discontinuation of IV therapy

Common Pitfalls to Avoid

• Excessive BP reduction: Too rapid or excessive lowering can lead to organ hypoperfusion, particularly in patients with chronic hypertension who have shifted autoregulation curves
• Inadequate monitoring: Failure to continuously monitor BP during initial treatment can lead to overshooting target BP
• Inappropriate medication selection: Using short-acting nifedipine or other inappropriate agents increases risk of precipitous BP decline
• Neglecting volume status: Many patients with malignant hypertension may be volume depleted due to pressure natriuresis 1
• Overlooking underlying causes: Failing to identify and address the underlying cause of hypertensive emergency

By following these evidence-based guidelines and selecting appropriate medications based on the specific clinical presentation, hypertensive emergencies can be effectively managed to minimize target organ damage and improve outcomes.