Should labs be started in a patient with severe alcohol intoxication?

Laboratory Testing in Severe Alcohol Intoxication

Laboratory testing should be initiated in patients with severe alcohol intoxication to assess for complications and guide management. 1, 2

Initial Assessment

• Blood alcohol concentration (BAC) should be measured to confirm intoxication and guide treatment decisions, particularly when alcohol use is combined with altered mental status, multiple drug overdose, head trauma, coma, seizures, or psychosis 3
• Complete blood count should be obtained to assess for neutrophilia (common in alcoholic hepatitis) and thrombocytopenia (may indicate advanced liver disease) 4, 1
• Liver function tests including AST, ALT, alkaline phosphatase, and bilirubin are essential to evaluate for alcohol-related liver injury 4, 1
  • An AST/ALT ratio >2 is highly suggestive of alcoholic liver disease, with ratios >3 being even more specific 1
  • AST levels are typically elevated 2-6 times the upper limit of normal in alcoholic hepatitis but rarely exceed 300 IU/mL 4

Additional Testing

• Electrolytes, glucose, and renal function tests should be performed to identify hypoglycemia, electrolyte imbalances, and renal dysfunction that may require correction 2
• Coagulation studies (PT/INR) are important to assess liver synthetic function and risk of bleeding, especially in patients with suspected alcoholic hepatitis 4
• Venous blood gas should be considered to evaluate acid-base status, as patients may develop metabolic acidosis with compensatory respiratory alkalosis 5
• Toxicology screening is indicated when multiple drug ingestion is suspected or when the clinical presentation is inconsistent with the degree of alcohol intoxication 3

Risk Stratification

• For patients with suspected alcoholic hepatitis, calculate the Maddrey Discriminant Function (mDF) using bilirubin and PT/INR to identify severe forms (mDF ≥32) 4
• The MELD score can also be used to assess severity, with scores between 17-20 indicating severe alcoholic hepatitis 4
• AUDIT questionnaire should be administered to screen for alcohol use disorder once the patient is stable 4, 1

Special Considerations

• Direct biomarkers such as ethyl glucuronide (EtG) in urine or hair may be useful for monitoring abstinence but are not necessary in the acute setting 4, 1
• Liver biopsy (preferably transjugular) should be considered in cases of diagnostic uncertainty or when precise staging is required, but is not routinely necessary in the emergency setting 4
• Imaging studies (ultrasound, CT, or MRI) may be indicated to evaluate for complications such as cirrhosis or to rule out other causes of liver disease 4

Common Pitfalls

• Normal liver function tests do not exclude significant alcohol-related liver disease 1
• Up to 20% of patients with alcohol use disorder and abnormal LFTs have coexisting liver disease etiologies 1
• GGT loses specificity for alcohol in advanced liver disease 1
• The AST/ALT ratio becomes less specific in the cirrhotic stage 1
• Failure to screen for dangerous behaviors (depression, suicidal ideation) is common but critical for patient safety 6

Follow-up Testing

• Patients should be referred to an alcohol addiction unit for follow-up to reduce the risk of relapse and complications related to alcohol abuse 2, 7
• Repeat liver function tests should be performed to monitor response to abstinence, which is the most effective intervention to reduce liver enzyme abnormalities 1