What is the initial treatment for a hypertensive emergency?

Initial Treatment for Hypertensive Emergency

For patients with hypertensive emergency, admission to an intensive care unit is recommended for continuous monitoring of blood pressure and target organ damage, with parenteral administration of appropriate intravenous antihypertensive medications. 1, 2

Definition and Assessment

• A hypertensive emergency is defined as severe blood pressure elevation (>180/120 mmHg) associated with evidence of new or worsening target organ damage 1, 2
• Target organ damage may include hypertensive encephalopathy, intracerebral hemorrhage, acute ischemic stroke, acute myocardial infarction, acute left ventricular failure with pulmonary edema, unstable angina pectoris, dissecting aortic aneurysm, acute renal failure, or eclampsia 1, 2
• The 1-year mortality rate associated with untreated hypertensive emergencies exceeds 79%, with a median survival of only 10.4 months 1, 2
• The actual blood pressure level may not be as important as the rate of blood pressure rise; patients with chronic hypertension often tolerate higher blood pressure levels than previously normotensive individuals 2

Initial Management Approach

• Immediate blood pressure reduction (not necessarily to normal) is required to prevent or limit further target organ damage 1
• Oral therapy is generally discouraged for hypertensive emergencies 1, 2
• For patients with compelling conditions (aortic dissection, severe preeclampsia/eclampsia, pheochromocytoma crisis), systolic blood pressure should be reduced to less than 140 mmHg during the first hour and to less than 120 mmHg in aortic dissection 1
• For patients without compelling conditions, systolic blood pressure should be reduced by no more than 25% within the first hour; then, if stable, to 160/100 mmHg within the next 2-6 hours; and then cautiously to normal during the following 24-48 hours 1, 2

First-Line Parenteral Medications

Calcium Channel Blockers

• Nicardipine: Initial 5 mg/h, increasing every 5 min by 2.5 mg/h to maximum 15 mg/h 1, 2
• Clevidipine: Initial 1-2 mg/h, doubling every 90 seconds until BP approaches target, then increasing by less than double every 5-10 min; maximum dose 32 mg/h; maximum duration 72 hours 1, 3

Vasodilators

• Sodium nitroprusside: Initial 0.3-0.5 μg/kg/min; increase in increments of 0.5 μg/kg/min to achieve BP target; maximum dose 10 μg/kg/min; duration of treatment should be as short as possible 1, 2
• Nitroglycerin: Initial 5 μg/min; increase in increments of 5 μg/min every 3-5 min to a maximum of 20 μg/min; particularly useful in patients with coronary ischemia or acute pulmonary edema 1, 2

Adrenergic Blockers

• Labetalol: Initial 0.3-1.0 mg/kg dose (maximum 20 mg) slow IV injection every 10 min or 0.4-1.0 mg/kg/h IV infusion up to 3 mg/kg/h 1, 2
• Esmolol: Loading dose 500-1000 μg/kg/min over 1 min followed by a 50-μg/kg/min infusion; for additional dosing, the bolus dose is repeated and the infusion increased in 50-μg/kg/min increments as needed to a maximum of 200 μg/kg/min 1

Medication Selection Based on Target Organ Damage

• Malignant Hypertension with/without TMA or Acute Kidney Failure: Initial therapy with Labetalol 2
• Hypertensive Encephalopathy: Initial therapy with Labetalol 2
• Acute Ischemic Stroke with BP >220 mmHg systolic or >120 mmHg diastolic: Initial therapy with Labetalol 2
• Acute Hemorrhagic Stroke with systolic BP >180 mmHg: Initial therapy with Labetalol 2
• Acute Coronary Syndrome: Initial therapy with Nitroglycerin 1, 2
• Acute Cardiogenic Pulmonary Edema: Initial therapy with Nitroprusside or Nitroglycerin 2
• Acute Aortic Disease: Initial therapy with Esmolol and Nitroprusside or Nitroglycerin 2

Important Precautions

• Excessive blood pressure reductions that can lead to renal, cerebral, or coronary ischemia should be avoided 1, 2
• Short-acting Nifedipine is no longer acceptable for the initial treatment of hypertensive emergencies or urgencies 1, 2, 4
• Sodium nitroprusside should be used with caution due to its toxicity, particularly with prolonged use 4, 5
• Large blood pressure reductions (more than 50% decrease in mean arterial pressure) have been associated with ischemic stroke and death 2
• Differentiate between hypertensive emergency (requiring immediate IV therapy) and hypertensive urgency (severe hypertension without acute end-organ damage, which can be managed with oral medications) 4, 5, 6