What is the treatment for a hypertensive crisis?

Treatment of Hypertensive Crisis

The treatment of hypertensive crisis requires immediate blood pressure reduction with parenteral antihypertensive agents for hypertensive emergencies (BP >180/120 mmHg with evidence of target organ damage), while hypertensive urgencies can be managed with oral antihypertensive medications. 1, 2

Definition and Classification

• Hypertensive crisis is defined as severe blood pressure elevation (>180/120 mmHg) and is categorized into two types based on the presence of target organ damage 2:

  • Hypertensive emergency: Severe BP elevation with evidence of new or worsening target organ damage requiring immediate BP reduction 1, 2
  • Hypertensive urgency: Severe BP elevation without progressive target organ damage 1, 2

• Without treatment, hypertensive emergencies carry a 1-year mortality rate >79% and median survival of only 10.4 months 2

Initial Management Approach

• Hypertensive emergencies require:

  • Immediate admission to an intensive care unit (ICU) for continuous monitoring 1, 2
  • Parenteral administration of titratable intravenous antihypertensive agents 1, 2
  • Specific drug choice and BP target determined by the type of end-organ damage 1

• Hypertensive urgencies can be managed with:

  • Oral BP-lowering agents 1
  • Outpatient treatment in most cases 3

Blood Pressure Reduction Goals

• For hypertensive emergencies:

  • Reduce mean arterial pressure by no more than 25% within the first hour 1
  • Then reduce to 160/100-110 mmHg within the next 2-6 hours 1
  • Further gradual reduction toward normal BP over the following 24-48 hours 1

• Special situations with different BP targets:

  • Aortic dissection: Reduce SBP to <120 mmHg and heart rate <60 bpm 1
  • Acute pulmonary edema: Reduce SBP to <140 mmHg 1
  • Pre-eclampsia/eclampsia: Reduce SBP to <160 mmHg and DBP to <105 mmHg 1

First-Line Intravenous Medications for Hypertensive Emergencies

• Labetalol: 20-80 mg IV bolus every 10 minutes or 0.4-1.0 mg/kg/h IV infusion 1, 4

  • Blocks both alpha and beta receptors, reducing blood pressure without significant reduction in heart rate 4
  • Particularly useful for hypertensive encephalopathy and malignant hypertension with renal failure 2

• Nicardipine: Initial dose of 5 mg/h, increasing every 5 minutes by 2.5 mg/h to maximum 15 mg/h 1, 5

  • Potent arteriolar vasodilator without significant direct depressant effect on myocardium 5, 6
  • Must be diluted before infusion (except for premixed bags) 5

• Sodium nitroprusside: Indicated for immediate reduction of blood pressure in hypertensive crises 7

  • Has reliable antihypertensive activity that begins immediately and ends when infusion is stopped 8
  • However, due to its toxicity, newer guidelines suggest avoiding it as first-line therapy 9, 6, 3

• Clevidipine: Newer agent with advantages in the management of hypertensive crises 9, 6

Laboratory Evaluation

• Essential tests in hypertensive crisis include:
  • Complete blood count (hemoglobin, platelets) 2
  • Basic metabolic panel (creatinine, sodium, potassium) 2
  • Lactate dehydrogenase (LDH) and haptoglobin 2
  • Urinalysis for protein and urine sediment examination 2
  • Troponins for patients with chest pain 2
  • Electrocardiogram (ECG) 2

Common Pitfalls to Avoid

• Excessive rapid BP reduction, which can lead to cerebral, renal, or coronary ischemia 1, 2
• Using short-acting nifedipine, which is no longer considered acceptable in the initial treatment of hypertensive emergencies 1, 9, 6
• Delayed laboratory testing - immediate assessment is crucial for appropriate management 2
• Overlooking secondary hypertension, which requires specific diagnostic workup after stabilization 2
• Sodium nitroprusside should be used with caution due to its toxicity 9, 6, 3
• Hydralazine, immediate release nifedipine, and nitroglycerin should not be considered first-line therapies 9, 3

Special Considerations

• For acute ischemic stroke: Avoid BP reduction within the first 5-7 days unless BP exceeds 220/120 mmHg 2
• For acute hemorrhagic stroke: Carefully lower systolic BP to 140-160 mmHg if presenting with systolic BP ≥220 mmHg 2
• For ischemic stroke patients eligible for reperfusion therapy: Maintain BP <180/105 mmHg for at least the first 24 hours after treatment 2
• Volume depletion from pressure natriuresis may occur, and intravenous saline may be needed to correct precipitous BP falls 2