Review Question - QID 214494

A 24-year-old man with an unknown past medical history presents to the emergency department with altered mental status. He was found stumbling around the mall profoundly confused until he passed out in a store. The patient is not able to offer a history but is protecting his airway. His temperature is 97.9°F (36.6°C), blood pressure is 114/64 mmHg, pulse is 110/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals a profoundly stuporous man with slurred speech who is unable to walk without assistance. He has fruity-smelling breath, and his clothes are covered in urine. Laboratory studies are ordered as seen below.

Hemoglobin: 13 g/dL
Hematocrit: 39%
Leukocyte count: 6,720/mm^3 with normal differential
Platelet count: 222,400/mm^3

Serum:
Na+: 130 mEq/L
Cl-: 99 mEq/L
K+: 4.3 mEq/L
HCO3-: 22 mEq/L
BUN: 15 mg/dL
Glucose: 129 mg/dL
Creatinine: 1.0 mg/dL
Ca2+: 10.2 mg/dL
Serum ethanol: 5 mg/dL
Osmolar gap: 16.4
Acetone: 10 mmol/L (normal < 3 mmol/L)

The patient is actively vomiting while in the department and complains of abdominal pain. Which of the following is the most likely etiology of this patient’s symptoms?