What is the treatment approach for hypertensive emergency and urgency?

Treatment Approach for Hypertensive Emergency and Urgency

In hypertensive emergencies, patients should be admitted to an intensive care unit for continuous monitoring of blood pressure and target organ damage, with parenteral administration of appropriate antihypertensive agents. 1

Definitions and Classification

• Hypertensive emergency: Severe BP elevation (>180/120 mmHg) with evidence of new or worsening target organ damage 1
• Hypertensive urgency: Severe BP elevation without evidence of acute or impending target organ damage 1

Management of Hypertensive Emergency

Initial Approach

• Admit to intensive care unit for continuous monitoring and parenteral therapy 1
• Choose antihypertensive agent based on specific type of target organ damage 1

BP Reduction Goals

• For most hypertensive emergencies: Reduce BP by no more than 25% within the first hour 1
• If stable after initial reduction, aim for 160/100 mmHg within the next 2-6 hours 1
• Cautiously normalize BP over the following 24-48 hours 1

Special Conditions (Compelling Indications)

• Aortic dissection: Reduce SBP to <140 mmHg in first hour, then to <120 mmHg 1, 2
• Severe preeclampsia/eclampsia: Reduce SBP to <140 mmHg in first hour 1, 2
• Pheochromocytoma crisis: Reduce SBP to <140 mmHg in first hour 1

Parenteral Medications for Hypertensive Emergencies

1. Calcium Channel Blockers

   • Nicardipine: Initial 5 mg/h, increasing every 5 min by 2.5 mg/h to maximum 15 mg/h 1, 3
   • Clevidipine: Initial 1-2 mg/h, doubling every 90 seconds until BP approaches target 1

2. Nitric Oxide-Dependent Vasodilators

   • Sodium nitroprusside: Initial 0.3-0.5 mcg/kg/min; increase in increments of 0.5 mcg/kg/min 1, 4
     • Caution: For infusion rates ≥4-10 mcg/kg/min or duration >30 min, thiosulfate can be coadministered to prevent cyanide toxicity 1
   • Nitroglycerin: Initial 5 mcg/min; increase in increments of 5 mcg/min every 3-5 min to maximum 20 mcg/min 1
     • Particularly useful in patients with coronary ischemia 5

3. Direct Vasodilators

   • Hydralazine: Initial 10 mg via slow IV infusion (maximum initial dose 20 mg); repeat every 4-6 h as needed 1

4. Adrenergic Blockers

   • Esmolol: Loading dose 500-1000 mcg/kg/min over 1 min followed by 50 mcg/kg/min infusion 1, 6
   • Labetalol: Initial 0.3-1.0 mg/kg dose (maximum 20 mg) slow IV injection every 10 min 1
   • Phentolamine: IV bolus dose 5 mg, additional boluses every 10 min as needed 1

Management of Hypertensive Urgency

• Do not require ICU admission 1
• Can be treated with oral antihypertensive medications 1, 4
• Reinstitute or intensify oral antihypertensive drug therapy 1
• Arrange appropriate follow-up 1

Important Considerations and Pitfalls

• Avoid excessive falls in BP that may precipitate renal, cerebral, or coronary ischemia 1, 5
• Short-acting nifedipine is no longer considered acceptable in the initial treatment of hypertensive emergencies or urgencies 1, 6
• Patients with chronic hypertension often tolerate higher BP levels than previously normotensive individuals 1
• The 1-year mortality rate for untreated hypertensive emergencies exceeds 79%, with median survival of only 10.4 months 1
• Non-adherence to antihypertensive medications is a common precipitating factor for hypertensive crises 1, 4
• When transferring to oral therapy, initiate oral medication upon discontinuation of IV therapy 3

Target Organ Damage in Hypertensive Emergencies

• Hypertensive encephalopathy 1
• Intracerebral hemorrhage 1
• Acute ischemic stroke 1
• Acute myocardial infarction 1
• Acute left ventricular failure with pulmonary edema 1
• Unstable angina pectoris 1
• Dissecting aortic aneurysm 1
• Acute renal failure 1
• Eclampsia 1