"I Can't Pee"

Dr. Josh Liu presented an interesting case today of an older gentleman with a history of CKD, HFpEF, PAD, and BPH who presented with subacute oliguria which progressed to anuria in the setting of recent treatment for prostatitis, found to have AKI on CKD and eventually diagnosed with ATN. We spent the majority of our time focusing on both differential diagnosis and initial management.

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Learning Points:

  • The DDx for AKI is expansive!! It can be divided into pre-renal, intrinsic, and post-renal causes -- each of which have long lists of differentials!

Pre-renal:

Decreased effective arterial volume (hypovolemia, cardiorenal, systemic vasodilatation), renal vasoconstriction (NSAIDs, ACEI/ARB, contrast, etc), large vessel disease (RAS, thrombosis, dissection, vasculitis, etc)

Intrinsic renal disease:

ATN (ischemia, toxins, contrast-induced), AIN (allergic, infection, infiltrative, autoimmune), small vessel disease (cholesterol emboli, HUS/TTP, DIC, etc), glomerulonephritis.

Post-renal disease:

bladder neck obstruction (BPH, prostate cancer, neurogenic bladder, etc), bilateral ureteral obstruction (malignancy, retroperitoneal fibrosis, nephrolithiasis, etc).

Work up including a detailed history and physical, electrolytes, UA, FeNa, renal ultrasound and potentially serologies or renal biopsy can be helpful when evaluating AKI.

Immediate management should focus on whether the patient needs urgent/emergent dialysis, including:

fluid overload, hyperkalemia, uremia, severe metabolic acidosis, or intoxication/toxins

We discussed management options including alternative imaging (when ultrasound is not available), when to call renal, temporizing measures, etc. This case actually presented at 6 pm near sign out time, thus we emphasized the importance of a safe, warm handoff to the night team as well.

Dr. Liu had several teaching points after reviewing a recent article published in Kidney & Blood Pressure Research, including: 1. AKI and certain risk factors (DM2, heart disease, severe Cr elevations) may increase risk of future AKI episodes, 2. AKIs are associated with worse CV and mortality outcomes, and 3. don't underestimate the effect of medications on the kidney!