Renal and Urological Systems Flashcards

A patient with chronic kidney disease stage 4 develops anemia. Which is the primary mechanism of anemia in CKD?

Answer: Decreased erythropoietin production by damaged kidneys

The peritubular fibroblasts of the kidney produce erythropoietin; CKD-related fibrosis and destruction reduce EPO synthesis, causing normocytic normochromic anemia.

On COMSAE, which acid-base disorder is expected in a patient with vomiting and nasogastric tube suctioning?

Answer: Metabolic alkalosis (hypochloremic, hypokalemic)

Loss of gastric HCl through vomiting or NG suction results in hypochloremic metabolic alkalosis with compensatory potassium loss via kidney aldosterone stimulation.

A 45-year-old woman with lupus develops worsening proteinuria and hematuria. Biopsy shows diffuse proliferative glomerulonephritis with subendothelial deposits (Class IV LN). What is the initial treatment?

Answer: High-dose corticosteroids plus mycophenolate or cyclophosphamide

Class IV lupus nephritis (diffuse proliferative) is the most severe form and requires aggressive immunosuppression with high-dose corticosteroids combined with mycophenolate mofetil or cyclophosphamide.

Which finding on renal ultrasound is most characteristic of autosomal dominant polycystic kidney disease (ADPKD)?

Answer: Bilaterally enlarged kidneys with multiple cysts

ADPKD is characterized by bilateral renal enlargement due to progressive replacement of normal parenchyma by numerous fluid-filled cysts derived from PKD1 or PKD2 mutations.

A hospitalized patient develops oliguria after receiving aminoglycoside antibiotics for 7 days. Urinalysis shows muddy brown granular casts. What type of acute kidney injury is present?

Answer: Acute tubular necrosis (ATN)

Aminoglycosides are directly nephrotoxic to proximal tubular cells, causing ATN characterized by muddy brown granular casts from sloughed tubular epithelial cells.

In a patient with chronic kidney disease, which dietary modification helps prevent secondary hyperparathyroidism?

Answer: Phosphate restriction and phosphate binders

Phosphate retention in CKD stimulates PTH secretion; dietary phosphate restriction combined with oral phosphate binders prevents secondary hyperparathyroidism and renal osteodystrophy.