What is the management of a hypertensive emergency?

From the Guidelines

Hypertensive emergency is a severe elevation in blood pressure (typically >180/120 mmHg) with evidence of acute end-organ damage requiring immediate treatment with intravenous antihypertensive medications, such as nicardipine, clevidipine, or labetalol, to reduce blood pressure by no more than 25% within the first hour, then to 160/100-110 mmHg within the next 2-6 hours, as recommended by the 2020 international society of hypertension global hypertension practice guidelines 1.

Key Considerations

• The choice of antihypertensive treatment is predominantly determined by the type of organ damage, as outlined in the 2019 esc council on hypertension position document on the management of hypertensive emergencies 1.
• Patients with acute hypertension-mediated organ damage, such as stroke, acute hypertensive microangiopathy, and encephalopathy, require rapid BP lowering, whereas those with ischaemic stroke may not require immediate BP lowering, as stated in the 2019 esc council on hypertension position document on the management of hypertensive emergencies 1.
• The therapeutic goal is to minimize target organ damage safely by rapid recognition of the problem and early initiation of appropriate antihypertensive treatment, as emphasized in the 2017 acc/aha/aapa/abc/acpm/ags/apha/ash/aspc/nma/pcna guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1.

Treatment Options

• First-line medications include:
  • Nicardipine (initial dose 5 mg/hr IV, titrated by 2.5 mg/hr every 5-15 minutes, maximum 15 mg/hr)
  • Clevidipine (1-2 mg/hr IV, doubled every 90 seconds until near target, maximum 32 mg/hr)
  • Labetalol (20-80 mg IV bolus every 10 minutes, or 0.5-2 mg/min infusion)
• Sodium nitroprusside (0.25-10 μg/kg/min IV) is effective but requires careful monitoring for cyanide toxicity, as noted in the example answer.

Important Notes

• Hypertensive emergency occurs when severely elevated blood pressure overwhelms autoregulatory mechanisms, causing endothelial damage, fibrinoid necrosis of arterioles, and subsequent organ ischemia, particularly affecting the brain, heart, kidneys, and eyes, as described in the example answer.
• The 1-year death rate associated with hypertensive emergencies is >79%, and the median survival is 10.4 months if the emergency is left untreated, highlighting the importance of prompt recognition and treatment, as stated in the 2017 acc/aha/aapa/abc/acpm/ags/apha/ash/aspc/nma/pcna guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1.

From the FDA Drug Label

Titration For a gradual reduction in blood pressure, initiate therapy at a rate of 5 mg/hr. If desired blood pressure reduction is not achieved at this dose, increase the infusion rate by 2. 5 mg/hr every 15 minutes up to a maximum of 15 mg/hr, until desired blood pressure reduction is achieved. For more rapid blood pressure reduction, titrate every 5 minutes.

Hypertensive Emergency Treatment:

• The initial infusion rate for nicardipine hydrochloride is 5 mg/hr.
• The infusion rate can be increased by 2.5 mg/hr every 15 minutes for gradual reduction or every 5 minutes for more rapid reduction, up to a maximum of 15 mg/hr.
• The goal is to achieve the desired blood pressure reduction while monitoring the patient closely 2.

From the Research

Definition and Classification of Hypertensive Emergency

• Hypertensive emergencies are characterized by the presence of acute end-organ damage, requiring immediate reduction in blood pressure with titratable, short-acting, intravenous antihypertensive agents 3.
• Hypertensive crises are categorized as either hypertensive emergencies or urgencies, depending on the degree of blood pressure elevation and presence of end-organ damage 3, 4.

Treatment of Hypertensive Emergency

• The primary goal of intervention in a hypertensive crisis is to safely reduce blood pressure, with the appropriate therapeutic approach depending on the patient's clinical presentation 3, 4.
• Patients with hypertensive emergencies are best treated in an intensive care unit with titratable, intravenous, hypotensive agents, such as labetalol, esmolol, fenoldopam, nicardipine, and clevidipine 3, 4, 5.
• Sodium nitroprusside, nifedipine, nitroglycerin, and hydralazine are not recommended as first-line therapies due to their potential adverse effects and toxicities 3, 5.

Management Strategies

• Rapid recognition and initiation of therapy are key to minimizing end-organ damage in patients with hypertensive emergency, with tailoring of drug selection according to individual patient characteristics optimizing management and potential outcomes 4, 6.
• An appreciation of cerebral autoregulation is crucial in treatment decisions, and hypertensive emergencies require intravenous antihypertensive medication, most safely given in high dependency or intensive care settings 6.

Comparison of Antihypertensive Agents

• Nicardipine and clevidipine are both dihydropyridine calcium channel blockers that provide unique benefits for blood pressure control, with no difference between agents for initial blood pressure control in the treatment of hypertensive crisis 7.
• Nicardipine achieved more sustained systolic blood pressure control, with a lower risk of rebound hypertension and significant cost savings compared to clevidipine 7.