Match each clinical patient presentation with the most likely corresponding urinalysis sediment finding.
- A 68-year-old man develops oliguria and a rapidly rising serum creatinine level two days after an emergency repair of a ruptured abdominal aortic aneurysm that was complicated by profound intraoperative hypotension.Muddy brown granular casts and renal tubular epithelial cells
- A 45-year-old woman presents with newly developed periorbital edema, dark-colored urine, and hypertension two weeks after recovering from a severe streptococcal pharyngeal infection.Red blood cell casts and dysmorphic erythrocytes
- A 52-year-old man develops a low-grade fever, a pruritic maculopapular rash, and acute kidney injury one week after starting treatment with a cephalosporin antibiotic for a skin infection.White blood cell casts and urinary eosinophils
- A 60-year-old man with a 20-year history of poorly controlled type 2 diabetes mellitus is evaluated for progressive lower extremity edema, significant proteinuria, and severe hypoalbuminemia.Oval fat bodies and fatty casts
Answer
The ischemic presentation matches with muddy brown granular casts; the post-infectious nephritic presentation matches with red blood cell casts; the medication-induced allergic presentation matches with white blood cell casts; and the diabetic nephrotic presentation matches with oval fat bodies.
Each correct pairing links a classic clinical presentation to its definitive microscopic urinary finding based on the compartment of the kidney affected. Ischemia affects the tubules (muddy brown casts), inflammation of the glomeruli allows RBC leakage (RBC casts), drug allergies inflame the interstitium (WBC casts), and severe podocyte damage causes massive lipiduria (fatty casts).
Step-by-Step Solution
Key Concept
Correlation of distinct acute kidney injury and glomerular disease mechanisms with their classic urinalysis sediment patterns.