A 43-year-old man comes to the emergency department due to a 3-day history of persistent headaches. The patient has a history of hypertension and has had poor medical follow-up. Blood pressure is 224/115 mm Hg and pulse is 67/min. He appears mildly confused during the physical examination, but no focal neurologic deficits are noted. Funduscopic examination shows bilateral papilledema. Serum creatinine is 1.4 mg/dL. An intravenous medication is initiated that causes arteriolar dilation while also improving renal perfusion and increasing natriuresis. Which of the following agents is most likely being used in this patient?

Question

A 43-year-old man comes to the emergency department due to a 3-day history of persistent headaches.  The patient has a history of hypertension and has had poor medical follow-up.  Blood pressure is 224/115 mm Hg and pulse is 67/min.  He appears mildly confused during the physical examination, but no focal neurologic deficits are noted.  Funduscopic examination shows bilateral papilledema.  Serum creatinine is 1.4 mg/dL.  An intravenous medication is initiated that causes arteriolar dilation while also improving renal perfusion and increasing natriuresis.  Which of the following agents is most likely being used in this patient?

Quizplus · Accepted Answer

11ec160b_3b93_1986_9249_17df1655d3b2_MD0001_00 This patient has severe hypertension. In addition, he has clinical evidence of secondary end-organ damage, including encephalopathy (eg, confusion), papilledema, and acute kidney injury (eg, elevated creatinine). This presentation is consistent with hypertensive emergency and requires aggressive treatment with immediate but controlled blood pressure reduction to minimize organ damage. Intravenous agents are preferred in hypertensive emergency due to their rapid action and dose titration ability. Fenoldopam is a short-acting, selective, peripheral dopamine-1 receptor agonist with little to no effect on alpha- or beta-adrenergic receptors. Dopamine-1 receptor stimulation activates adenylyl cyclase and raises intracellular cyclic AMP, resulting in vasodilation of most arterial beds with a corresponding decrease in systemic blood pressure. Renal vasodilation is particularly prominent and leads to increased renal perfusion, increased urine output, and natriuresis (ie, sodium excretion). This makes fenoldopam especially beneficial in patients with hypertensive emergency and renal insufficiency. (Choice A) Esmolol is a short-acting, cardioselective beta-1 receptor antagonist. It works by reducing heart rate and myocardial contractility. Esmolol is not a vasodilator and does not increase renal perfusion. (Choice C) Hydralazine is a direct arteriolar vasodilator; however, it does not dilate renal arterioles and may decrease renal perfusion and encourage sodium and fluid retention. It is not often used in hypertensive emergency because it is associated with reflex sympathetic activation, resulting in increased heart rate and contractility. (Choice D) Nitroglycerin is a rapid-acting venodilator that decreases preload and cardiac output. It causes only minimal arterial dilation and does not improve renal perfusion. Nitroglycerin is primarily used to reduce myocardial oxygen demand in acute coronary syndrome. (Choice E) Phenylephrine is an alpha-adrenergic agonist that causes an increase in systemic vascular resistance due to arterial vasoconstriction. It is used in patients with hypotension or shock and is contraindicated in hypertensive emergency. Educational objective: Fenoldopam is a selective peripheral dopamine-1 receptor agonist. It causes vasodilation of systemic and renal arterioles to lower blood pressure while also increasing renal perfusion, urine output, and natriuresis, making it useful in the treatment of hypertensive emergency in patients with renal insufficiency. __________ References: Fenoldopam. (http://www.ncbi.nlm.nih.gov/pubmed/30252314)

A 43-Year-Old Man Comes to the Emergency Department Due to a 3-Day