IV agent choice in hypertensive emergency with AKI and TMA

Question

A 57-year-old man with a history of hypertension and coronary artery disease presents to the emergency department with headache and blurry vision for the last 24 hours. He denies chest pain. Medications include amlodipine, hydrochlorothiazide, and lisinopril. He notes that he was recently traveling and forgot several doses of his medications. Home BP is typically 150–160/90–100 mm Hg. BP is 224/122 mm Hg, heart rate is 62/min, and body mass index is 38 kg/m². Heart examination is notable for an S4 gallop. Lung examination reveals fine crackles at both bases. Fundoscopic examination shows papilledema. Laboratory data: hemoglobin 11 g/dL (reference 14–18); platelet count 120,000/μL (150,000–450,000); haptoglobin 60 mg/dL (83–267); lactate dehydrogenase 420 U/L (80–225); troponin I 0.04 ng/mL (≤0.04); creatinine 2.1 mg/dL (baseline, 1.3) (0.7–1.3). EKG shows left ventricular hypertrophy but no ST segment deviations or T-wave abnormalities. Chest x-ray shows increased opacities at both lung bases and a normal mediastinum. Which of the following is the next BEST step in management?

Accepted Answer

D. Nicardipine — The next best step in management of this patient presenting with a hypertensive emergency is nicardipine.

This patient presents with hypertensive emergency, characterized by uncontrolled hypertension (systolic BP ≥180 mm Hg and/or diastolic BP ≥120 mm Hg) with evidence of end-organ damage. This patient has AKI and evidence of microangiopathic hemolytic anemia. Nonadherence to treatment of chronic hypertension is a common precipitant of hypertensive emergency. IV therapy is indicated for the management of hypertensive emergencies. Generally, the choice of medication is directed at the specific clinical presentation. Nicardipine may be used in most hypertensive emergencies, with the notable exception of acute decompensated heart failure. Reflex tachycardia can occur so control of heart rate may be necessary, particularly if there is concomitant cardiac ischemia.

Patients with chronic hypertension may tolerate high BP without cerebral edema, but because of impaired autoregulation, may be at risk for cerebral hypoperfusion and ischemia with overly rapid BP correction. Thus, a reasonable goal would be to titrate nicardipine IV continuous infusion to decrease BP by 20–25% in the first hour and then resume the oral antihypertensive regimen 6–12 hours later, with BP reaching target at approximately 48 hours.

Hydralazine may cause unpredictable BP responses and by itself may be deleterious in patients with underlying coronary artery disease, as reflex tachycardia and sympathetic stimulation may provoke coronary ischemia.

Nitroglycerin (NTG) IV would be most appropriate in patients with an acute coronary syndrome, which is not present here. NTG commonly provokes or exacerbates headache and would not be preferred in this patient whose presenting complaint included headache.

Nitroprusside is a rapid-acting antihypertensive agent suitable for hypertensive emergencies but should be avoided in patients with AKI or advanced CKD because of risk of cyanide toxicity.

Note that hypertension-induced thrombotic microangiopathy may indicate an underlying complement disorder.

IV agent choice in hypertensive emergency with AKI and TMA

Explanation

Why each option

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