During a routine follow-up appointment, a 34-year-old female is evaluated for persistently… — USMLE Step 3

During a routine follow-up appointment, a $34$ -year-old female is evaluated for persistently elevated blood pressure. She was diagnosed with hypertension six months ago and is currently adherent to a regimen of maximum-dose amlodipine, chlorthalidone, and lisinopril. Despite this therapy, her home blood pressure readings consistently range from $160/100$ to $175/110 \text{ mm Hg}$ . The patient mentions occasional mild headaches but otherwise feels well. She does not smoke or consume alcohol. Family history is notable for hypertension in her father, diagnosed at age $55$ .

Vital signs in the office today show a blood pressure of $168/104 \text{ mm Hg}$ and a heart rate of $76/\text{min}$ . Physical examination reveals a thin adult with a body mass index of $22 \text{ kg/m}^2$ . Cardiopulmonary examination is unremarkable. Auscultation of the abdomen reveals a soft, high-pitched systolic bruit over the right upper quadrant.

Laboratory studies are obtained and compared to baseline values from three weeks ago, just prior to the addition of lisinopril to her regimen:

Laboratory Parameter	Current Value	Baseline (3 weeks ago)
Serum sodium	$139 \text{ mEq/L}$	$140 \text{ mEq/L}$
Serum potassium	$4.1 \text{ mEq/L}$	$4.0 \text{ mEq/L}$
Serum creatinine	$1.8 \text{ mg/dL}$	$0.9 \text{ mg/dL}$
Blood urea nitrogen	$24 \text{ mg/dL}$	$12 \text{ mg/dL}$

Which of the following is the most appropriate next step in the diagnostic workup?

Renal duplex ultrasonographyCevap
B
Computed tomography angiography of the abdomen
C
Catheter-directed renal arteriography
D
Plasma aldosterone concentration to plasma renin activity ratio
E
Measurement of 24-hour urine fractionated metanephrines

Cevap

Renal duplex ultrasonography

The correct approach for a patient with high clinical suspicion for renovascular hypertension (indicated by young age, resistant hypertension, an abdominal bruit, and an ACE inhibitor-induced acute kidney injury) is to perform non-invasive vascular imaging. Because this patient has a significantly elevated serum creatinine (

1.8 \text{ mg/dL}

), tests requiring iodinated contrast pose a high risk of contrast-induced nephropathy. Renal duplex ultrasonography provides excellent sensitivity for detecting renal artery stenosis without utilizing nephrotoxic agents, making it the ideal initial test in this diagnostic sequence.

Adım Adım Çözüm

Analyze the clinical presentation and identify the underlying syndrome.

The patient is a young female with resistant hypertension, an abdominal bruit, and an acute doubling of serum creatinine after starting an ACE inhibitor (lisinopril).

This constellation of findings is highly specific for bilateral renal artery stenosis or severe unilateral stenosis, likely due to fibromuscular dysplasia in this demographic.

Evaluate the current physiological state to guide safe test selection.

The patient has acute kidney injury, evidenced by the jump in serum creatinine from

0.9 \text{ mg/dL}

1.8 \text{ mg/dL}

Recognizing the acute kidney injury is critical because it dictates which imaging modalities are safe to use.

Determine the optimal sequence for diagnostic imaging.

Renal duplex ultrasonography is selected as the next step.

It is a highly sensitive and specific non-invasive screening tool that does not utilize nephrotoxic iodinated contrast or gadolinium, making it the safest initial test for a patient with compromised renal function.

Anahtar Kavram

In patients with suspected renovascular hypertension and impaired renal function (such as an ACE inhibitor-induced acute kidney injury), renal duplex ultrasonography is the preferred initial diagnostic imaging modality because it avoids the risk of contrast-induced nephropathy associated with CTA.

Tahmini Süre:1m 15s

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

Bu konudan daha fazla soru