ITE Nephrology and Hypertension 3

Question 1

A 25-year-old woman is found to have BP of 170/100 mmHg on routine exam. Labs show hypokalemia, suppressed plasma renin activity, and elevated aldosterone. CT shows no adrenal mass. What is the best next diagnostic step?

Accepted Answer

Adrenal vein sampling

Answer

Adrenal vein sampling is the gold standard for differentiating unilateral aldosterone-producing adenoma from bilateral adrenal hyperplasia when CT is non-diagnostic.

Question 2

A 58-year-old man on hemodialysis for 8 years presents with bone pain and a serum calcium of 11.2 mg/dL, phosphorus of 5.8 mg/dL, and intact PTH of 850 pg/mL. What is this condition called and what surgical intervention may be needed?

Accepted Answer

Tertiary hyperparathyroidism; parathyroidectomy if refractory to cinacalcet

Answer

Tertiary hyperparathyroidism occurs in long-term dialysis patients when autonomous PTH hypersecretion persists and may require parathyroidectomy if calcimimetics fail.

Question 3

A 48-year-old HIV-positive man on tenofovir disoproxil fumarate presents with a proximal renal tubular acidosis, glucosuria with normal serum glucose, hypophosphatemia, and hypokalemia. What syndrome does this represent?

Accepted Answer

Fanconi syndrome

Answer

Tenofovir disoproxil fumarate can cause mitochondrial toxicity in proximal tubular cells, leading to Fanconi syndrome with global proximal tubule dysfunction.

Question 4

A 35-year-old woman with lupus nephritis class IV on mycophenolate and prednisone has a serum creatinine rise from 1.1 to 2.4 mg/dL over 3 months with worsening proteinuria. What is the best next step?

Accepted Answer

Repeat kidney biopsy

Answer

A repeat kidney biopsy in lupus nephritis is essential to determine whether the class has transformed, activity has increased, or chronic scarring has developed before changing therapy.

Question 5

A 66-year-old man with hypertension is started on chlorthalidone. Two weeks later he reports muscle cramps. Labs: Na 138 mEq/L, K 3.0 mEq/L, Cl 94 mEq/L, HCO3 29 mEq/L, urine Cl 60 mEq/L. What acid-base disorder is present?

Accepted Answer

Metabolic alkalosis with appropriate respiratory compensation

Answer

Thiazide diuretics cause metabolic alkalosis via volume contraction, increased aldosterone, and direct H+ and K+ loss in the collecting duct.

ITE - Internal Medicine In-Training Exam Practice Test

ITE - Internal Medicine In-Training Exam Practice Test

ITE Nephrology and Hypertension 3