Acute Kidney Injury Flashcards
7 cards from real Internal Medicine Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Acute Kidney Injury flashcards as text
A 50-year-old diabetic man develops AKI after starting an ACE inhibitor. Renal artery duplex shows >70% stenosis bilaterally. What is the mechanism of AKI in this patient?
Answer: Loss of efferent arteriolar tone causing drop in glomerular perfusion pressure
In bilateral renal artery stenosis, glomerular filtration depends on angiotensin II–mediated efferent vasoconstriction; ACE inhibitors remove this compensation, causing GFR to fall precipitously.
Which of the following is an ABSOLUTE indication for emergent dialysis in AKI?
Answer: Uremic pericarditis with friction rub
Uremic pericarditis is an absolute indication for urgent dialysis, as it indicates severe uremia that can progress to life-threatening pericardial effusion or tamponade.
A 65-year-old man with hypertension develops AKI with blood pressure of 240/130 mmHg. Urinalysis shows RBC casts and 3+ proteinuria. LDH is elevated and peripheral smear shows schistocytes. What diagnosis best explains his AKI?
Answer: Thrombotic microangiopathy (malignant hypertension)
Malignant hypertension causes thrombotic microangiopathy with schistocytes on peripheral smear, hemolysis (elevated LDH), and glomerular injury (RBC casts, proteinuria).
Which of the following parameters is used to calculate the Fractional Excretion of Urea (FEUrea), and when is it preferred over FENa?
Answer: Preferred in patients on diuretics; less affected by diuretic-induced natriuresis than FENa
FEUrea <35% suggests prerenal AKI and is preferred over FENa in patients receiving diuretics, since diuretics artificially raise urine sodium excretion independent of volume status.
A 40-year-old woman presents with AKI, bilateral uveitis, and granulomas on biopsy. Which diagnosis should be considered?
Answer: Sarcoidosis with granulomatous interstitial nephritis
Sarcoidosis can cause AKI through granulomatous interstitial nephritis and hypercalcemia-mediated nephrocalcinosis, and is associated with uveitis.
A patient in the ICU receives tobramycin for 10 days. On day 8, creatinine begins rising. Urine shows β2-microglobulinuria. What pattern of AKI is expected?
Answer: Proximal tubular necrosis with non-oliguric AKI
Aminoglycosides preferentially accumulate in proximal tubular cells, causing non-oliguric ATN; β2-microglobulinuria reflects proximal tubular dysfunction.
After successful kidney transplantation, a recipient develops AKI on day 3 with oliguria and a biopsy showing interstitial edema, lymphocytic infiltration, and tubulitis. What is the most likely cause?
Answer: Acute cellular rejection (T-cell mediated)
Acute cellular rejection occurring days to weeks post-transplant is characterized by tubulitis and lymphocytic interstitial infiltration on biopsy and requires augmented immunosuppression.