IM Essentials: Ch. 70 - Acute Kidney Injury

Question 1

Intrinsic AKI is divided into two categories: ______________.

Answer 1

oliguric (<400 mL/day) and non-oliguric (>400 mL/day)

The lower the output, the worse the prognosis.

Question 2

Hepatorenal syndrome results in _____________.

Answer 2

extreme vasoconstriction of the renal vasculature; it cannot be reversed by fluid administration

Question 3

Describe an approach to suspected intrinsic AKI by HPI.

Answer 3

•Examine the patient’s history for features of things that might clue you into the diagnosis:

• AIN: recent medications (penicillins, cephalosporins in particular)
• ATN: recent contrast, rhabdo, aminoglycosides, or hypovolemia
• GN: nephritic/nephrotic features,

Question 4

What labs would you order to work up suspected intrinsic AKI?

Answer 4

• AIN:
- urine microscopy (“spin the urine”): WBCs and eosinophils

•GN:

• urine microscopy: RBC casts and dysmorphic RBCs
• urinalysis: proteinuria
• vasculitis panel if systemic symptoms: ANCA, complement, anti-ds-DNA ab, anti-GBM antibody, HBV surface Ag, HCV ab, ASO

•ATN:

• urine microscopy: muddy casts
• BMP: electrolyte abnormalities per phase