What is the management of a hypertensive crisis?

Management of Hypertensive Crisis

The management of hypertensive crisis requires immediate intervention with a controlled blood pressure reduction strategy based on whether it is a hypertensive emergency (with end-organ damage) or hypertensive urgency (without end-organ damage). 1, 2

Definition and Classification

Hypertensive crisis is defined as severe blood pressure elevation (>180/120 mmHg) that requires prompt clinical attention and is classified into two categories:

• Hypertensive Emergency: Severe BP elevation with evidence of new or worsening target organ damage
• Hypertensive Urgency: Severe BP elevation without evidence of target organ damage

Signs of End-Organ Damage (Emergency)

• Neurological: Hypertensive encephalopathy, stroke, intracranial hemorrhage
• Cardiovascular: Acute coronary syndrome, acute heart failure, pulmonary edema, aortic dissection
• Renal: Acute kidney injury, acute renal failure
• Other: Eclampsia, microangiopathic hemolytic anemia

Assessment and Diagnosis

• Evaluate for end-organ damage with:

  • Physical examination (fundoscopy, neurological exam, cardiac exam)
  • Laboratory tests (renal panel, urinalysis)
  • ECG
  • Additional testing based on symptoms (echocardiogram, neuroimaging, chest CT)

• Warning sign: Bradycardia with severe hypertension may indicate increased intracranial pressure 2

Treatment Approach

Hypertensive Emergency

1. Immediate hospitalization in ICU with continuous BP monitoring
2. IV antihypertensive therapy with titratable short-acting agents
3. BP reduction targets:
   • For most conditions: Reduce BP by no more than 25% within first hour, then to 160/100 mmHg within 2-6 hours, then cautiously to normal over 24-48 hours 1, 2
   • For specific conditions (aortic dissection, severe preeclampsia/eclampsia, pheochromocytoma crisis): Reduce SBP to <140 mmHg during first hour and to <120 mmHg in aortic dissection 1

Hypertensive Urgency

1. Outpatient management with oral antihypertensive medications
2. Gradual BP reduction over 24-48 hours
3. Close follow-up within 1-7 days

Medication Selection for Hypertensive Emergency

First-Line IV Medications

Clinical Presentation	First-Line Treatment	Alternative
Most hypertensive emergencies	Labetalol	Nicardipine
Acute coronary event	Nitroglycerin	Labetalol
Acute pulmonary edema	Nitroglycerin + loop diuretic	Labetalol + loop diuretic
Aortic dissection	Esmolol + Nitroprusside	Labetalol, Nicardipine

Specific IV Medication Dosing

• Labetalol: 10 mg IV over 1-2 min, may repeat or double every 10-20 min to max 300 mg 2
• Nicardipine: Initial 5 mg/h, increasing every 5 min by 2.5 mg/h to max 15 mg/h 1
• Clevidipine: Initial 1-2 mg/h, doubling every 90 sec until BP approaches target 1
• Sodium nitroprusside: Initial 0.3-0.5 mcg/kg/min; increase in increments of 0.5 mcg/kg/min; max 10 mcg/kg/min; use for shortest duration possible 1, 3
• Nitroglycerin: Initial 5 mcg/min; increase in increments of 5 mcg/min every 3-5 min to max 20 mcg/min 1

Special Populations

Pregnancy-Related Hypertensive Crisis

• IV labetalol or nicardipine with magnesium 2

Acute Stroke

• For ischemic stroke with BP >220/120 mmHg: Labetalol or nicardipine
• For hemorrhagic stroke with SBP >180 mmHg: Labetalol or nicardipine 2

Stimulant Intoxication

• Start with benzodiazepines before antihypertensive therapy 2

Transition to Oral Therapy and Follow-up

1. Monitoring: Check BP every 1-2 hours initially
2. Transition: When BP is stable, overlap IV and oral therapy briefly
3. Observation: Monitor for several hours with vital signs every 30 minutes during first 2 hours
4. Follow-up: Schedule within 24 hours for urgencies, continue monthly until target BP is reached 2

Potential Pitfalls

• Avoid overly aggressive BP reduction - can lead to cerebral, cardiac, or renal hypoperfusion 2
• Avoid sublingual nifedipine - risk of precipitous BP decline 2
• Avoid hydralazine as first-line - unpredictable response and prolonged duration 1
• Use sodium nitroprusside cautiously - risk of cyanide toxicity with prolonged use 1, 4
• Don't miss underlying causes - pheochromocytoma, renovascular disease, medication non-adherence

The untreated 1-year mortality rate for hypertensive emergencies exceeds 79%, with median survival of only 10.4 months, highlighting the critical importance of prompt and appropriate management 1.