A 43-year-old man is evaluated in the emergency department for abdominal pain. He has a history of alcohol abuse, with repeated episodes of acute intoxication requiring medical therapy. He also has a history of several episodes of acute pancreatitis, but no history of seizure disorder. He takes no medications.
On physical examination, temperature is 37.4 °C (99.3 °F), blood pressure is 112/66 mm Hg, and pulse rate is 76/min. BMI is 20. There is no evidence of trauma or head injury. There is no evidence of ascites. The abdomen is tender to palpation. Neurologic examination reveals normal pupillary and corneal reflexes, normal muscle tone, and a downgoing plantar reflex.
Blood urea nitrogen | 28 mg/dL (10 mmol/L) |
Calcium | 8.6 mg/dL (2.2 mmol/L) |
Creatinine | 1.2 mg/dL (106.1 µmol/L) (baseline, 0.8 mg/dL [70.7 µmol/L]) |
Electrolytes: | |
Sodium | 135 mEq/L (135 mmol/L) |
Potassium | 4.9 mEq/L (4.9 mmol/L) |
Chloride | 96 mEq/L (96 mmol/L) |
Bicarbonate | 12 mEq/L (12 mmol/L) |
Ethanol | 62 mg/dL (0.062 g/dL) |
Glucose | 72 mg/dL (4 mmol/L) |
Lactate | 0.8 mEq/L (0.8 mmol/L) |
Plasma osmolality | 293 mOsm/kg H2O |
Phosphorus | 3.7 mg/dL (1.2 mmol/L) |
Urinalysis | pH 5.5; specific gravity 1.020; no blood, ketones, or cells |
Which of the following is the most likely cause of this patient's acidosis?