When the Cause Is Not Crystal Clear

A 55-year-old woman with a history of chronic renal insufficiency presented to the emergency department with recurrent falls, dizziness, and lethargy over a period of several days. She had been vomiting repeatedly during this time and was unable to keep down liquids or food. She reported that she did not have chest pain, shortness of breath, a change in bowel habits, dysuria, or hematuria. On examination, the patient's blood pressure was 64/40 mm Hg, and the heart rate was 100 beats per minute. The body-mass index (the weight in kilograms divided by the square of the height in meters) was 43. The serum creatinine level was 1041 μmol per liter (11.8 mg per deciliter), the estimated glomerular filtration rate (GFR) was 3 ml per minute per 1.73 m2 of body-surface area, the blood urea nitrogen (BUN) level was 57.8 mmol per liter (162 mg per deciliter), and the potassium level was 8.1 mmol per liter, as compared with her most recent values for creatinine (120 μmol per liter [1.4 mg per deciliter]), estimated GFR (40 ml per minute per 1.73 m2), and BUN (5.5 mmol per liter [15 mg per deciliter]). The urine output was only 5 to 15 ml per hour. Blood and urine cultures were sent. © 2020 Massachusetts Medical Society.