A 73-year-old man underwent esophageal resection for cancer. He had a history of hypertension that was treated with an angiotensin receptor blocker. Preoperative estimated glomerular filtration rate (GFR) was 98 mL/min/1.73 m2. On the second postoperative day, body temperature was 38.6°C. Chest x-ray revealed bilateral lung consolidations consistent with pneumonia. Blood pressure decreased from 145/72 mm Hg to 96/53 mm Hg with a heart rate of 105/min. The patient was admitted to the intensive care unit (ICU) with acute respiratory failure and was placed on mechanical ventilation. In the ICU, urine output was 50 mL over 3 hours. On day 3, he received 4.5 L of Ringer lactate over 12 hours. Laboratory values are shown in the Table.