Alcoholic ketoacidosis is a metabolic complication of alcohol use and starvation characterized by hyperketonemia and anion gap metabolic acidosis without significant hyperglycemia. Alcoholic ketoacidosis causes nausea, vomiting, and abdominal pain. Diagnosis is by history and findings of ketoacidosis without hyperglycemia. Treatment is IV saline solution and dextrose infusion.
Alcoholic ketoacidosis is attributed to the combined effects of alcohol and starvation on glucose metabolism.
Pathophysiology of Alcoholic Ketoacidosis
Alcohol diminishes hepatic gluconeogenesis and leads to decreased insulin secretion, increased lipolysis, impaired shunting of fatty acids to mitochondria, fatty acid oxidation, and subsequent ketogenesis, causing an elevated anion gap metabolic acidosis. Growth hormone, epinephrine, cortisol, and glucagon are all increased. Plasma glucose levels are usually low or normal, but mild hyperglycemia sometimes occurs.
Symptoms and Signs of Alcoholic Ketoacidosis
Typically, an alcohol binge leads to vomiting and the cessation of alcohol or food intake for ≥ 24 hours. During this period of starvation, vomiting continues and abdominal pain develops, leading the patient to seek medical attention. Pancreatitis may occur.
Diagnosis of Alcoholic Ketoacidosis
Calculation of anion gap
Exclusion of other disorders
Diagnosis requires a high index of suspicion; similar symptoms in a patient with alcohol use disorder may result from acute pancreatitis, methanol or ethylene glycol poisoning (see table Symptoms and Treatment of Specific Poisons), or diabetic ketoacidosis (DKA). Often, blood alcohol levels are no longer elevated when patients present with alcoholic ketoacidosis.
In patients suspected of having alcoholic ketoacidosis, serum electrolytes (including magnesium), blood urea nitrogen (BUN) and creatinine, glucose, ketones, amylase, lipase, and plasma osmolality should be measured. Urine should be tested for ketones. Patients who appear significantly ill and those with positive ketones should have arterial blood gas and serum lactate measurements.
The absence of hyperglycemia makes diabetic ketoacidosis improbable. Patients with mild hyperglycemia may have underlying diabetes mellitus, which may be recognized by elevated levels of glycosylated hemoglobin (HbA1C).
Typical laboratory findings include
Ketonemia and ketonuria
Detection of acidosis may be complicated by concurrent metabolic alkalosis due to vomiting, resulting in a relatively normal pH; the main clue is the elevated anion gap. If history does not rule out toxic alcohol ingestion as a cause of the elevated anion gap, serum methanol and ethylene glycol levels should be measured.
Calcium oxalate crystals in the urine also suggests ethylene glycol poisoning.
Lactic acid levels are often elevated because of hypoperfusion and the altered balance of reduction and oxidation reactions in the liver.
Treatment of Alcoholic Ketoacidosis
Wernicke encephalopathy or Korsakoff psychosis
Ketoacidosis and gastrointestinal symptoms usually respond rapidly. Use of insulin is appropriate only if there is any question of atypical diabetic ketoacidosis or if hyperglycemia > 300 mg/dL (> 16.7 mmol/L) develops.
Key Points
Alcoholic ketoacidosis is caused by the combined effects of alcohol and starvation on glucose metabolism; it is characterized by hyperketonemia and elevated anion gap metabolic acidosis without significant hyperglycemia.
Measure serum and urine ketones and electrolytes and calculate a serum anion gap.
