Match each clinical presentation of acute kidney injury (AKI) to the most appropriate primary differential diagnosis based on the history and diagnostic findings.
- A 68-year-old male with a history of benign prostatic hyperplasia presents with lower abdominal discomfort, absent urine output for 12 hours, and a palpably distended bladder.Obstructive uropathy
- A 45-year-old female in the intensive care unit receiving intravenous gentamicin for sepsis develops a progressively rising serum creatinine; urinalysis reveals muddy brown granular casts.Acute tubular necrosis
- A 25-year-old male presents with acute onset of hemoptysis and dark-colored urine; urinalysis is notable for dysmorphic red blood cells and red blood cell casts.Glomerulonephritis
- A 55-year-old male with a history of severe systolic heart failure presents with orthopnea; laboratory studies show a blood urea nitrogen to creatinine ratio of 32:1 and a fractional excretion of sodium of 0.6%.Prerenal azotemia
Answer
The presentations match as follows: The patient with benign prostatic hyperplasia and anuria matches with obstructive uropathy. The patient receiving gentamicin with muddy brown casts matches with acute tubular necrosis. The patient with hemoptysis and red blood cell casts matches with glomerulonephritis. The patient with heart failure and a low fractional excretion of sodium matches with prerenal azotemia.
Each clinical vignette provides classic, pathognomonic findings for the distinct categories of acute kidney injury. Proper differentiation ensures appropriate subsequent management, such as volume status optimization for prerenal causes versus prompt catheterization for postrenal obstructive causes.
Step-by-Step Solution
Key Concept
Formulating a differential diagnosis for acute kidney injury requires categorizing the etiology into prerenal, intrinsic, and postrenal causes based on the patient's medical history, physical examination, and characteristic urinary indices.
Estimated Time:1m 30s