A 72-year-old man is admitted to the ICU with a 3-day history of worsening shortness of breath and edema. He is found to have pulmonary edema with severe hypoxia requiring intubation and mechanical ventilation. Medical history is significant for ischemic cardiomyopathy, coronary artery disease, myocardial infarction, hypertension, hyperlipidemia, and benign prostatic hyperplasia. Medications on admission are aspirin, lisinopril, carvedilol, atorvastatin, and as-needed furosemide.
On physical examination, the patient is afebrile, blood pressure is 92/60 mm Hg, and pulse rate is 112/min. Estimated central venous pressure is 14 cm H2O. Diffuse crackles are heard throughout both lung fields. Cardiovascular examination reveals an S3 gallop. There is lower extremity edema to the knees.
A dobutamine infusion is started. A urinary catheter is inserted, and he is given intravenous furosemide with a urine output of 230 mL over the next 4 hours.
Blood urea nitrogen | 76 mg/dL (27.1 mmol/L) |
Serum creatinine | 3.0 mg/dL (265.2 µmol/L) (baseline: 1.9 mg/dL [168 µmol/L]) |
Serum electrolytes | Normal |
Urine sodium | 64 mEq/L (64 mmol/L) |
Fractional excretion of sodium | 1.9% |
Fractional excretion of urea | 8.8% |
Urinalysis | Specific gravity 1.018; pH 5.5; 1+ protein; 1-2 erythrocytes/hpf; 2-4 leukocytes/hpf; moderate hyaline and fine granular casts |
Which of the following is the most likely diagnosis?