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Emergency and Acute Medicine – Alcoholic ketoacidosis
Basics description
Alcoholic ketoacidosis is caused by increased ketone body production resulting from dehydration due to nausea and vomiting with inhibition of antidiuretic hormone, leading to elevated stress hormone release and ketogenesis. Hepatic glycogen stores are depleted because of malnutrition or reduced carbohydrate intake. Ethanol metabolism increases the NADH/NAD ratio, promoting free fatty acid production and favoring β-hydroxybutyrate over acetoacetate as the predominant ketone.
Etiology
Alcoholic ketoacidosis typically occurs in malnourished chronic alcohol users following a recent episode of heavy alcohol consumption. Nausea, vomiting, or abdominal pain lead to abrupt cessation of alcohol intake. Presentation usually occurs within 12–72 hours.
Diagnosis signs and symptoms
Dehydration is common. Fever is usually absent unless infection is present. Tachycardia frequently occurs due to hypovolemia with orthostatic changes and concurrent alcohol withdrawal. Tachypnea is common, often with deep, rapid Kussmaul respirations. Nausea, vomiting, and abdominal pain are the most frequent symptoms and are usually diffuse with nonspecific tenderness; epigastric pain is common. Rebound tenderness, abdominal distension, and hypoactive bowel sounds are uncommon and should prompt evaluation for alternative pathology. Urine output is decreased due to hypovolemia. Mental status is typically minimally altered; significant alteration requires evaluation for head injury, cerebrovascular accident, intracranial hemorrhage, hypoglycemia, alcohol withdrawal, encephalopathy, or toxic ingestion. Visual disturbances may occur.
History often reveals chronic alcohol use with a recent binge followed by abrupt cessation. Physical examination commonly shows dehydration, ketotic breath odor, Kussmaul respirations, and palmar erythema.
Essential workup
An increased anion gap metabolic acidosis due to ketone accumulation should be identified. Toxic alcohol ingestion and other causes of anion gap metabolic acidosis must be excluded.
Diagnosis tests and interpretation
Laboratory findings demonstrate increased anion gap metabolic acidosis as the hallmark. Mixed acid–base disorders are common and may include respiratory alkalosis, metabolic alkalosis from vomiting, hyperchloremic acidosis, and mild lactic acidosis related to dehydration and ethanol metabolism. Severe lactic acidosis suggests alternative pathology such as hypoxia, seizures, or shock. Urine and serum nitroprusside tests are positive but underestimate severity because β-hydroxybutyrate predominates and is not detected; results may paradoxically increase during treatment. Electrolyte abnormalities include low bicarbonate, hypokalemia, hypocalcemia, hypophosphatemia, and hypomagnesemia. Glucose levels are usually normal or mildly elevated, though hypoglycemia may occur. Alcohol levels may be negative. BUN and creatinine are mildly elevated due to dehydration. CBC may show mild leukocytosis, anemia, and thrombocytopenia related to chronic alcohol use. Urinalysis shows ketonuria without glucosuria. Amylase and lipase may be elevated with pancreatitis. Liver enzymes may be mildly elevated. The osmolal gap may be increased; values greater than 20 mOsm/kg warrant evaluation for methanol or ethylene glycol ingestion, correcting for ethanol by dividing the ethanol level by 4.6.
Chest radiography is indicated if pneumonia is suspected. Abdominal imaging is considered for acute abdomen. CT of the head is required with trauma or unexplained altered mental status.
Differential diagnosis
Causes of elevated anion gap metabolic acidosis include alcoholic ketoacidosis, toxic ingestions, acetaminophen toxicity, fulminant hepatic failure, antiretroviral toxicity, toluene, methanol, metformin, uremia, diabetic ketoacidosis, paraldehyde, iron, isoniazid, lactic acidosis, ethylene glycol, salicylates, and starvation ketosis. Other considerations include hypovolemia from GI bleeding or sepsis and abdominal pain from pancreatitis, gastritis, hepatitis, perforated ulcer, alcohol withdrawal, viral illness, or bowel obstruction.
Treatment pre hospital
Provide supportive care with IV access, 0.9% normal saline, oxygen, and cardiac monitoring. Evaluate for toxic ingestion, diabetic history, and coexisting illness such as gastrointestinal bleeding.
Initial stabilization therapy
Initiate cardiac monitoring and supplemental oxygen. Administer naloxone, thiamine, and dextrose if mental status is altered. Begin IV normal saline with a 500 mL–1 L bolus and continue resuscitation as needed to promote renal ketone clearance.
Ed treatment procedures
Administer antiemetics and benzodiazepines for alcohol withdrawal. Begin dextrose-containing fluids such as D5NS, which resolve metabolic abnormalities more rapidly than saline alone by restoring glycogen stores and stimulating endogenous insulin. Avoid dextrose if significant hyperglycemia is present. Administer IV thiamine before glucose to prevent Wernicke encephalopathy. Sodium bicarbonate is rarely indicated and reserved for severe acidosis with cardiovascular compromise. Anticipate and correct electrolyte shifts, particularly hypokalemia, hypophosphatemia, and hypomagnesemia. Insulin is not indicated and may cause hypoglycemia.
Medication
Dextrose 50%: 25 g IV
Lorazepam: 2 mg IV, titrate to effect
Naloxone: 2 mg IV
Ondansetron: 4–8 mg IV
Prochlorperazine: 5–10 mg IV slowly
Promethazine: 12.5–25 mg IV
Thiamine: 100 mg IV
Follow up disposition
Admission is indicated for persistent metabolic acidosis, hypovolemia, ongoing vomiting, unclear abdominal pain, comorbid illness, or electrolyte abnormalities requiring monitoring. Many patients can be managed in an observation unit for 12–24 hours if tolerating oral intake, metabolic abnormalities resolve, and no additional illness is present.
Follow up recommendations
Provide counseling and referral for alcohol cessation.
Pearls and pitfalls
Aggressive volume resuscitation with dextrose-containing fluids is essential. Always administer thiamine before glucose. Monitor electrolytes and glucose closely. Evaluate unexplained elevated osmolal gaps. Continuous cardiac monitoring is required due to the risk of dysrhythmias, electrolyte disturbances, and alcoholic cardiomyopathy.
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