What is the management of a hypertensive emergency?

Management of Hypertensive Emergency

Hypertensive emergency requires immediate hospitalization with intravenous antihypertensive therapy to reduce blood pressure in a controlled manner, targeting a 20-25% reduction in mean arterial pressure within the first hour to prevent further target organ damage. 1, 2

Definition and Diagnosis

• Hypertensive emergency is defined as severely elevated blood pressure (often >180/120 mmHg) with evidence of acute hypertension-mediated organ damage requiring immediate blood pressure reduction 1, 2
• The diagnosis is based not only on the absolute blood pressure value but on the presence of acute end-organ damage 2
• Patients without acute end-organ damage have hypertensive urgency, not emergency, and can be treated with oral medications 2

Target Organ Damage Assessment

• Cardiac damage: Acute cardiogenic pulmonary edema, coronary ischemia/acute myocardial infarction, heart failure 1, 2
• Brain damage: Hypertensive encephalopathy, acute stroke (ischemic or hemorrhagic) 1, 3
• Retinal damage: Advanced hypertensive retinopathy (Grade III-IV) with bilateral flame-shaped hemorrhages, cotton wool spots, and papilledema 1, 2
• Kidney damage: Acute renal failure, thrombotic microangiopathy (TMA) 1, 3
• Large artery damage: Acute aortic disease (aneurysm or dissection) 1, 2

General Treatment Principles

• Admit patients to intensive care unit for close monitoring and intravenous BP-lowering therapy 1, 3
• Initial goal: Reduce mean arterial pressure by 20-25% within the first hour (except in specific conditions) 1, 3
• If stable, further reduce BP to 160/100 mmHg within 2-6 hours, then gradually to normal over 24-48 hours 3
• Avoid excessive BP reduction as it can lead to organ hypoperfusion (cerebral, cardiac, or renal ischemia) 1, 3

Medication Selection by Clinical Presentation

First-Line Medications for Specific Conditions

• Malignant hypertension with/without TMA or acute renal failure: Labetalol 2, 3
• Hypertensive encephalopathy: Labetalol 2, 3
• Acute ischemic stroke with BP >220/120 mmHg: Labetalol 2, 3
• Acute ischemic stroke with indication for thrombolysis and BP >185/110 mmHg: Nicardipine 1
• Acute hemorrhagic stroke with systolic BP >180 mmHg: Labetalol 2, 3
• Acute coronary event: Nitroglycerin 1, 2
• Acute cardiogenic pulmonary edema: Nitroprusside or Nitroglycerin 1, 2
• Acute aortic disease: Esmolol plus Nitroprusside or Nitroglycerin 1, 2, 3
• Eclampsia/severe pre-eclampsia: Labetalol or Nicardipine plus Magnesium sulfate 1, 3

Practical Administration of Key Medications

• Nicardipine:

  • Administer by slow continuous infusion via central line or large peripheral vein 4
  • Start at 5 mg/h, increase by 2.5 mg/h every 5-15 minutes to maximum 15 mg/h 2, 4
  • Change infusion site every 12 hours if administered via peripheral vein 4
  • Produces dose-dependent decreases in blood pressure 4

• Labetalol:

  • Initial 20 mg IV over 2 minutes, then 20-80 mg every 10 minutes up to 300 mg total 2
  • Particularly useful in hypertensive encephalopathy as it preserves cerebral blood flow 1

• Nitroprusside:

  • Start with 0.3-0.5 μg/kg/min, increase in steps of 0.5 μg/kg/min to maximum 10 μg/kg/min 2
  • Treatment duration should be as short as possible 2
  • Most reliable antihypertensive activity, begins immediately and ends when infusion stops 5

Common Pitfalls to Avoid

• Using short-acting nifedipine, which can cause unpredictable blood pressure drops 1, 3
• Excessive rapid BP reduction, which can precipitate cerebral, cardiac, or renal ischemia 3
• Delayed transition to oral therapy once stabilized 1
• Failure to recognize medication non-compliance as a common underlying cause 3

Post-Emergency Management

• Transition to oral antihypertensive therapy once stabilized 1, 3
• Investigate potential secondary causes of hypertension 3
• Continue monitoring for at least 24-48 hours to ensure stable blood pressure control 3