Lab

Blood Alcohol

search

Blood Alcohol, Blood Alcohol Level, Blood Alcohol Content, Blood Alcohol Concentration, Serum Ethanol, Alcohol Breath Test, Breathalyzer, Biomarkers of Alcohol Use, Urine Ethyl Glucuronide, Urine Ethyl Sulfate, Phospatidylethanol

  • See Also
  1. Alcohol Use Disorder
  2. Alcohol Intoxication
  3. Cirrhosis
  4. Alcoholic Hepatitis
  5. Urine Drug Screen
  • Definitions
  1. Blood Alcohol Content (BAC, Blood Alcohol Concentration)
    1. Measure of Alcohol content (and Intoxication) in blood
    2. Measured in grams of Alcohol per 100 ml of blood (expressed as percent)
    3. Example: 0.10% = 0.10 g Alcohol per 100 ml blood = 100 mg/dl = 22 mmol/L
  2. Alcohol Breath Test (Breathalyzer)
    1. Measured as grams Alcohol per 210 Liters of breath
  • Labs
  • Blood Alcohol Level
  1. Blood Alcohol Effects in non-habitual drinkers
    1. Blood Alcohol Content 0.02% to 0.05% (20 to 50 mg/dl, 4.4 to 11 mmol/L)
      1. Decreased fine motor coordination
    2. Blood Alcohol Content 0.05% to 0.10% (50 to 100 mg/dl, 11 to 22 mmol/L)
      1. Impaired judgement
      2. Impaired concentration
    3. Blood Alcohol Content 0.10% to 0.15% (100 to 150 mg/dl, 22 to 33 mmol/L)
      1. Altered gait and balance
    4. Blood Alcohol Content 0.15% to 0.25% (150 to 250 mg/dl, 33 to 55 mmol/L)
      1. Lethargy
      2. May need assistance to sit upright
    5. Blood Alcohol Content 0.30% (300 mg/dl, 66 mmol/L)
      1. Coma
    6. Blood Alcohol Content 0.40% (400 mg/dl, 88 mmol/L)
      1. Respiratory Depression
    7. References
      1. Marx (2002) Rosen Emergency Medicine, Elsevier, p. 2513
      2. (2022) Clinical Effects of Blood Alcohol Concentration, UpToDate, accessed 4/21/2022
  2. Blood Alcohol Metabolism
    1. Blood Alcohol decreases 0.02 g/dl/h in non-Alcoholics
    2. Blood Alcohol decreases 0.03 g/dl/h in Alcoholics
  • Labs
  • Biomarkers of Alcohol Use
  1. Ethyl Glucuronide
    1. Urine Alcohol biomarker
      1. Positive if Alcohol use in last 3 days (longer if Renal Insufficiency)
      2. Detects ingestions of as little as 5 g of Alcohol
    2. Test Sensitivity: 76%
    3. Test Specificity: 93%
  2. Ethyl Sulfate
    1. Urine Alcohol biomarker
      1. Positive if Alcohol use in last 3 days (longer if Renal Insufficiency)
    2. Test Sensitivity: 82%
    3. Test Specificity: 86%
  3. Phospatidylethanol
    1. Blood Alcohol biomarker
      1. Positive if Alcohol use in last 2 to 3 weeks
      2. No major confounding factors (e.g. age, BMI, gender, renal or liver disease)
      3. More expensive than the urine biomarkers
    2. Test Sensitivity: 100%
    3. Test Specificity: 96%
  • References
  1. Stewart (2013) Alcohol Clin Exp Res 37(1): 150-5 [PubMed]
  2. Andresen-Streichert (2017) 30(6): 611-20 [PubMed]