ABIM Nephrology

Question 1

A 60-year-old diabetic patient has proteinuria of 3.5 g/day, hypoalbuminemia, and peripheral edema. Serum creatinine is normal. What is the diagnosis?

Accepted Answer

Nephrotic syndrome

Answer

Nephrotic syndrome is defined by proteinuria >3.5 g/day, hypoalbuminemia, edema, and hyperlipidemia, often with lipiduria.

Question 2

A patient presents with oliguria after surgery. BUN is 42 mg/dL, creatinine is 1.4 mg/dL (BUN:Cr ratio = 30). Urine sodium is 8 mEq/L and FENa is 0.5%. What is the most likely diagnosis?

Accepted Answer

Prerenal azotemia

Answer

Prerenal azotemia is characterized by elevated BUN:Cr ratio (>20), low urine sodium (<20 mEq/L), and FENa <1%, reflecting intact tubular function with avid sodium reabsorption.

Question 3

A patient with CKD stage 4 has a serum potassium of 6.2 mEq/L with peaked T waves on ECG. What is the immediate treatment?

Accepted Answer

IV calcium gluconate

Answer

IV calcium gluconate stabilizes the cardiac membrane immediately in hyperkalemia with ECG changes, though it does not lower potassium levels.

Question 4

Which acid-base disorder is most commonly associated with diarrhea?

Accepted Answer

Non-anion gap metabolic acidosis

Answer

Diarrhea causes loss of bicarbonate-rich intestinal secretions, resulting in non-anion gap (hyperchloremic) metabolic acidosis.

Question 5

A 35-year-old woman with SLE develops nephrotic-range proteinuria and hematuria. Renal biopsy shows wire-loop lesions on light microscopy. What is the most likely diagnosis?

Accepted Answer

Lupus nephritis class IV (diffuse proliferative)

Answer

Wire-loop lesions on renal biopsy represent subendothelial immune complex deposits and are pathognomonic of diffuse proliferative (class IV) lupus nephritis.

ABIM - American Board of Internal Medicine Practice Test

ABIM - American Board of Internal Medicine Practice Test

ABIM Nephrology