Acute Kidney Injury USMLE Step 1 Practice Question
A 56-year-old man with a 10-year history of type 2 diabetes and hypertension presents to the emergency department with progressive nausea, malaise, and dyspnea over 2 days. He denies chest pain, fever, or recent infections. Vital signs show BP 168/98 mmHg, HR 102/min, RR 24/min. Laboratory studies reveal: Serum creatinine: 4.8 mg/dL (baseline 1.0 mg/dL 3 months ago)
BUN: 68 mg/dL
Serum glucose: 156 mg/dL
Serum pH: 7.18
HCO3−: 13 mEq/L
Anion gap: 18 mEq/L
Serum ketones: Negative
Urinalysis: No ketones, muddy brown casts, proteinuria
Arterial blood gas shows metabolic acidosis with appropriate respiratory compensation Which of the following is the most likely diagnosis?
Answer choices
- ADiabetic ketoacidosis with concurrent acute kidney injury
- BHyperglycemic hyperosmolar state complicated by sepsis
- CUremic metabolic acidosis due to acute kidney injuryCorrect answer
- DLactic acidosis secondary to cardiogenic shock
- EMixed metabolic acidosis from concurrent diabetic ketoacidosis and uremia
- FSalicylate toxicity with metabolic acidosis
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