Nephrology

Question 1

What electrolyte derangements are associated with too much HCTZ?

Answer 1

Low K
Low Na
High Cr
High bicarb (metabolic alkalosis)
Orthostatic Hypotension

Question 2

What is Pyroglutamic acidosis?

Answer 2

This a HAGMA (with appropriate compensation) associated with chronic, XS Tylenol use.

Pyroglutamic acidosis occurs in patients receiving therapeutic doses of acetaminophen on a chronic basis in the setting of critical illness, poor nutrition, liver disease, chronic kidney disease, or a strict vegetarian diet; diagnosis can be confirmed by measuring urine levels of pyroglutamic acid.

Presents as mental status change.

Question 3

How can you differentiate HELLP from Pre-eclampsia in a woman in the 3rd trimester with HTN, low platelets, and elevated LFTs?

Answer 3

HELLP is a microangiopathic hemolytic anemia, and you would need schistocytes, high bili

Question 4

What can patient do to prevent Ca oxalate stones from recurring?

Answer 4

1. Increase fluid intake
2. Potassium citrate

Note: Low Protein and Low Ca actually INCREASES calciuria and will make stones worse

Note: Patients with chronic diarrhea and malabsorption are at increased risk for forming calcium oxalate stones for three reasons. First, because of the diarrhea and concomitant metabolic acidosis, urine citrate, an inhibitor of crystallization, is often reduced. In addition, volume depletion from the diarrhea decreases urine volume and thus increases the concentration of calcium and oxalate in the urine. Finally, in malabsorption, especially fat malabsorption as occurs in chronic pancreatitis, enteric calcium binds to fat as opposed to oxalate, leaving oxalate free to be absorbed and excreted in the urine.

Question 5

What is the most likely composition of a kidney stone in a patient with crohn’s disease?

Answer 5

Ca Oxalate.

Patients with diarrhea who are volume depleted and have a metabolic acidosis are at increased risk for developing a kidney stone, particularly stones composed of calcium oxalate and uric acid. In a patient with Crohn disease and chronic diarrhea, the most likely composition of the stone is calcium oxalate because the chronic metabolic acidosis (suggested by the low serum bicarbonate concentration and relatively low urine pH) increases calcium loss from bone and decreases citrate excretion.

Question 6

An 81-year-old man is hospitalized for an acute onset of edema in his legs and abdomen. History is significant for chronic back pain, for which he takes daily ibuprofen. He has no other symptoms.

VSS. No rash. Cardiac exam wnl. Estimated CVP wnl. The lungs are clear on examination. Ascites is noted. There is 3-mm pitting edema of the extremities to the mid thigh.

Laboratory studies:
Albumin: 2.1 g/dL (low)
Creatinine: 2.9 mg/dL (256.4 µmol/L)
Electrolytes: Normal
Urinalysis: No blood; 4+ protein
Urine protein-creatinine ratio: 7200 mg/g (<30)
24-Hour urine output: 1.5 L
Doppler ultrasound of the kidneys is unremarkable.

What is the most likely dx?
What is the next step in mgmt?

Answer 6

Dx: Minimal Change Disease

Mgmt: Kidney Biopsy

MCG is the cause of the nephrotic syndrome in 10% to 15% of adults, with a significantly higher incidence in elderly patients (≥65 years of age) and very elderly patients (≥80 years of age). Most cases are idiopathic, but secondary causes must be considered in adults, including medications such as NSAIDs.

You need a biopsy to make the dx.

Question 7

What FEna value supports a diagnosis of hypovolemia in the setting of an oliguric patient?

Answer 7

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