Renal and Urinary Systems Flashcards

A patient with chronic kidney disease has a GFR of 22 mL/min/1.73 m². According to KDIGO staging, what CKD stage is this?

Answer: Stage 4

KDIGO defines CKD Stage 4 as GFR 15–29 mL/min/1.73 m², which corresponds to severely decreased kidney function.

Which urinalysis finding is most characteristic of nephrotic syndrome?

Answer: Massive proteinuria (>3.5 g/day)

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

A patient presents with oliguria, flank pain, and hematuria after starting an NSAID. Urinalysis shows muddy brown casts and elevated BUN/creatinine. What type of acute kidney injury is this?

Answer: Intrinsic renal AKI (ATN)

NSAIDs reduce prostaglandin-mediated afferent arteriole dilation, causing ischemia and acute tubular necrosis, characterized by muddy brown granular casts.

Which feature best distinguishes prerenal AKI from intrinsic renal AKI?

Answer: BUN:creatinine ratio >20:1 and FeNa <1%

In prerenal AKI the tubules are intact so they avidly reabsorb sodium (FeNa <1%) and urea, raising the BUN:creatinine ratio above 20:1.

The sympathetic nervous system innervates the kidney via which spinal levels, relevant to osteopathic viscerosomatic reflexes?

Answer: T10–L1

Renal sympathetic innervation originates from T10–L1, and somatic dysfunction at these levels can reflect renal pathology through viscerosomatic reflex arcs.

Which diuretic class acts on the thick ascending limb of the loop of Henle and is most potent for volume removal in acute pulmonary edema?

Answer: Loop diuretics

Loop diuretics (e.g., furosemide) inhibit the Na-K-2Cl cotransporter in the thick ascending loop, producing the greatest diuresis of any diuretic class.