What is the management of a hypertensive emergency?

Management of Hypertensive Emergency

Hypertensive emergency requires immediate blood pressure reduction with intravenous medications tailored to the specific type of end-organ damage present. 1

Definition and Diagnosis

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

Target Organ Damage Assessment

• Heart: acute pulmonary edema, coronary ischemia/infarction, heart failure 1, 2
• Brain: hypertensive encephalopathy, acute ischemic or hemorrhagic stroke 1, 3
• Retina: advanced hypertensive retinopathy (grade III-IV) with flame-shaped hemorrhages, cotton-wool spots, papilledema 1, 2
• Kidneys: acute kidney failure, thrombotic microangiopathy (TMA) 1, 3
• Large arteries: acute aortic disease (aneurysm or dissection) 1, 2

General Treatment Principles

• Admit patients to ICU for close monitoring and intravenous BP-lowering medications 1, 4
• Initial goal: reduce mean arterial pressure by no more than 25% within minutes to 1 hour 3
• If stable, further reduce BP to 160/100-110 mmHg within 2-6 hours 3
• Gradually normalize BP over the next 24-48 hours if well tolerated 3
• Avoid excessive BP reduction which can precipitate renal, cerebral, or coronary ischemia 3, 4

First-Line Medications by Clinical Presentation

Malignant Hypertension with/without TMA or Acute Renal Failure

• Target: Reduce MAP by 20-25% over several hours 5
• First-line: Labetalol IV 5, 1
• Alternatives: Nitroprusside, Nicardipine, Urapidil 5

Hypertensive Encephalopathy

• Target: Reduce MAP by 20-25% immediately 5
• First-line: Labetalol IV 5, 1
• Alternatives: Nitroprusside, Nicardipine 5

Acute Ischemic Stroke

• For BP >220/120 mmHg or with thrombolytic therapy (BP >185/110 mmHg)
• Target: Reduce MAP by 15% within 1 hour 5, 3
• First-line: Labetalol IV 5, 1
• Alternatives: Nicardipine, Nitroprusside 5

Acute Hemorrhagic Stroke

• Target: Maintain systolic BP between 130-180 mmHg immediately 5
• First-line: Labetalol IV 5, 1
• Alternatives: Urapidil, Nicardipine 5

Acute Coronary Event

• Target: Reduce systolic BP <140 mmHg immediately 5
• First-line: Nitroglycerin IV 5, 1
• Alternatives: Urapidil, Labetalol 5

Acute Cardiogenic Pulmonary Edema

• Target: Reduce systolic BP <140 mmHg immediately 5
• First-line: Nitroprusside or Nitroglycerin (with loop diuretic) 5, 1
• Alternative: Urapidil (with loop diuretic) 5

Acute Aortic Disease

• Target: Reduce systolic BP <120 mmHg and heart rate <60 bpm immediately 5
• First-line: Esmolol plus Nitroprusside or Nitroglycerin 5, 1
• Alternatives: Labetalol or Metoprolol, Nicardipine 5

Eclampsia and Severe Pre-eclampsia/HELLP

• Target: Maintain systolic BP <160 mmHg and diastolic BP <105 mmHg immediately 5
• First-line: Labetalol or Nicardipine plus Magnesium sulfate 5, 1

Medication Administration

Nicardipine IV

• Start with 5 mg/hr, increase by 2.5 mg/hr every 5 minutes to maximum 15 mg/hr 1, 6
• Administer by slow continuous infusion via central line or large peripheral vein 6
• Change infusion site every 12 hours if administered via peripheral vein 6
• Compatible with most IV fluids except Sodium Bicarbonate and Lactated Ringer's 6

Labetalol IV

• Initial 20 mg IV over 2 minutes, then 20-80 mg every 10 minutes up to total dose of 300 mg 1
• Preferred in patients with hypertensive encephalopathy as it leaves cerebral blood flow relatively intact 5

Nitroprusside IV

• Start with 0.3-0.5 μg/kg/min, increase in steps of 0.5 μg/kg/min, maximum 10 μg/kg/min 1
• Keep treatment duration as short as possible due to potential toxicity 1, 7
• Use with caution in patients with increased intracranial pressure or renal dysfunction 7, 8

Important Caveats

• Never use short-acting nifedipine for hypertensive emergencies 1, 3
• Excessive BP reduction can lead to ischemic stroke and death 1, 4
• Patients often have medication non-compliance as an underlying cause 3
• After stabilization, investigate potential secondary causes of hypertension 3
• Monitor for at least 24-48 hours to ensure stable BP control 3