ITE Nephrology and Hypertension 5

Question 1

A 52-year-old man with diabetes presents with serum creatinine rising from 1.0 to 1.8 mg/dL after starting lisinopril. Renal artery duplex shows elevated resistive indices bilaterally with post-stenotic turbulence. What should be done?

Accepted Answer

Discontinue lisinopril and pursue further imaging to assess for bilateral renal artery stenosis

Answer

A >30% rise in creatinine after ACE inhibitor initiation suggests bilateral renal artery stenosis or stenosis in a solitary kidney; ACE inhibitor should be stopped and vascular imaging pursued.

Question 2

A 28-year-old woman with systemic lupus erythematosus presents with serum creatinine of 2.1 mg/dL, 4+ proteinuria, red cell casts, C3 18 mg/dL (low), and anti-dsDNA titer of 1:640. Kidney biopsy shows diffuse proliferative lesions in >50% of glomeruli. What is the LN class?

Accepted Answer

Class IV

Answer

Diffuse proliferative lupus nephritis involving >50% of glomeruli is classified as class IV (diffuse) by the ISN/RPS classification.

Question 3

A 68-year-old man on hydrochlorothiazide presents with serum sodium of 122 mEq/L. He appears euvolemic. Urine osmolality is 450 mOsm/kg and urine sodium is 55 mEq/L. TSH and morning cortisol are normal. What is the most appropriate treatment?

Accepted Answer

Discontinue thiazide and fluid restrict to 1 L/day

Answer

Thiazide-induced SIADH-like hyponatremia requires stopping the offending drug and fluid restriction; thiazides impair renal diluting capacity making them a common cause.

Question 4

A 44-year-old man with alcohol use disorder presents with acute kidney injury. Urine microscopy shows muddy brown granular casts and renal tubular epithelial cells. FENa is 3.2%. What is the most likely diagnosis?

Accepted Answer

Acute tubular necrosis

Answer

Muddy brown granular casts and RTECs on urinalysis with FENa >2% are the hallmark of acute tubular necrosis.

Question 5

A 61-year-old woman with resistant hypertension (BP 158/96 mmHg on ACEI, amlodipine, and chlorthalidone) has plasma aldosterone-to-renin ratio of 35 (ng/dL)/(ng/mL/h). CT adrenals are normal. What is the next step?

Accepted Answer

Adrenal vein sampling

Answer

An elevated ARR with biochemically confirmed primary hyperaldosteronism requires adrenal vein sampling to distinguish unilateral adenoma (surgical) from bilateral hyperplasia (medical).

ITE - Internal Medicine In-Training Exam Practice Test

ITE - Internal Medicine In-Training Exam Practice Test

ITE Nephrology and Hypertension 5