Renal, Urinary System and Electrolytes

Question 1

Acute Tubular Necrosis features

Answer 1

Can follow hypovolemic shock

BUN:Crea 10-15

Urine Osml 300-350

FeNa > 2%

NaU > 20 mEq/L

Muddy brown granular casts

Question 2

White Blood Cell Casts

Answer 2

Interstitial nephritis / Pyelonephritis

Question 3

Fatty Casts

Answer 3

Neprhotic syndrome

Question 4

Contrast Induced Nephropathy

Answer 4

Direct contrast insult leading to acute tubular necrosis

Renal vasoconstriction, leading to pre-renal injury, even in the absence of volume depletion

Question 5

Water deprivation test effects

Answer 5

Diabetes insipidus: there’s resistance to ADH, so after deprivation, the urine remains diulted

Primary Polydipsia: ADH kicks in and urine gets concentrated (Osm > 600)