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 55-year-old man with multiple myeloma presents with AKI, hypercalcemia, and Bence Jones proteinuria. Which mechanism directly causes AKI in this condition?
Answer: Light chain cast nephropathy obstructing tubular lumens
Myeloma cast nephropathy occurs when light chains (Bence Jones proteins) precipitate with Tamm-Horsfall protein in distal tubules, forming obstructing casts that cause AKI.
Which approach to fluid resuscitation in AKI has been shown to be superior to normal saline in reducing the risk of hyperchloremic metabolic acidosis and worsening renal function?
Answer: Balanced crystalloids (Lactated Ringer's or PlasmaLyte)
Balanced crystalloids have lower chloride content than normal saline and have been shown in trials (SMART, SALT-ED) to reduce rates of major adverse kidney events.
A 35-year-old pregnant woman at 36 weeks gestation develops AKI with thrombocytopenia, microangiopathic hemolytic anemia, and elevated liver enzymes. What is the most likely diagnosis?
Answer: HELLP syndrome
HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) can cause AKI through TMA and is a severe complication of pre-eclampsia requiring urgent delivery.
A 70-year-old man with AKI, low complement (C3, C4), RBC casts, and a history of recent streptococcal skin infection is most likely experiencing:
Answer: Post-infectious (post-streptococcal) glomerulonephritis
Post-streptococcal glomerulonephritis presents 1–4 weeks after skin or throat infection with RBC casts, complement consumption (low C3), and nephritic syndrome.
During evaluation of AKI, a renal ultrasound shows bilateral small echogenic kidneys. What does this finding most likely indicate?
Answer: Chronic kidney disease as the underlying condition, not true AKI
Small echogenic kidneys on ultrasound indicate chronic scarring and fibrosis, suggesting the elevated creatinine reflects CKD rather than a true acute process.
Which renal replacement therapy modality is preferred in hemodynamically unstable ICU patients with AKI?
Answer: Continuous renal replacement therapy (CRRT)
CRRT is preferred in hemodynamically unstable patients because it removes solutes and fluid slowly and continuously, minimizing hypotension compared to intermittent hemodialysis.
A patient recovering from AKI due to sepsis now has a urine output of 4 L/day with a fixed urine osmolality of 310 mOsm/kg. This pattern is most consistent with which phase of AKI recovery?
Answer: Polyuric recovery phase with impaired tubular concentrating ability
The polyuric phase of ATN recovery shows high urine volume but isosthenuria (fixed osmolality ~300 mOsm/kg) due to persistent tubular dysfunction before full recovery.