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    Patent Pending

    Estimated Ethanol (and Toxic Alcohol) Serum Concentration Based on Ingestion

    Predicts ethanol concentration based on ingestion of alcohol.
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    INSTRUCTIONS

    Allows estimation of maximal predicted serum concentration of alcohol based on volume and concentration ingested. Assumes 0.6 L/kg volume of distribution.

    When to Use
    Pearls/Pitfalls
    Why Use

    Predicting serum concentration of toxic alcohols.

    • The formula makes several assumptions to approximate maximal predicted serum concentration:
      • Complete alcohol absorption.
      • Absence of alcohol metabolism or elimination.
      • Absence of volume contraction effects.
      • Alcohol specific gravity disregarded.
      • Gender and age differences in pharmacokinetics discounted.
    • The estimated serum concentration from ingestion of a given volume of alcohol will differ depending on which alcohol is ingested.

    Estimates maximal predicted serum concentration of alcohol based on volume and concentration ingested.

    lbs
    %
    mL
    Ethanol
    Methanol
    Ethylene glycol
    Diethylene glycol

    Result:

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    Next Steps
    Evidence
    Creator Insights

    Advice

    Amounts of alcohol ingested reported by history are often inaccurate (especially in children).

    Management

    Recommendations for starting treatment:

    Overdose

    Treatment

    Methanol

    • Concentration ≥20 mg/dL (6.2 mmol/L), OR
    • Documented recent history of ingestion and osmolal gap >10 mOsm/L, OR
    • Suspected methanol ingestion and at least two of the following: arterial pH <7.3, serum carbon dioxide level <20 mmol/L, and osmolal gap >10 mOsm/L.

    Ethylene glycol

    • Concentration ≥20 mg/dL (3.2 mmol/L), OR
    • Documented history of ingestion an osmolal gap >10 mOsm/L, OR
    • Suspected ethylene glycol ingestion and at least three of the following: arterial pH <7.3, serum carbon dioxide level <20 mmol/L, osmolal gap >10 mOsm/L, and oxalate crystalluria.

    Diethylene glycol

    Immediate treatment recommended for any history of diethylene glycol ingestion.

    Isopropyl alcohol and propylene glycol

    No recommendations for treating with fomepizole, as it would prolong the symptoms of intoxication. The treatment is supportive for both and neither is generally toxic unless massive ingestions requiring vasopressor support.

    From Brent 2009.

    Critical Actions

    • Seemingly small ingestions of alcohols can lead to significant serum concentrations (i.e., methanol/ethylene glycol concentrations that require treatment with fomepizole).
    • Toxic alcohols (methanol, ethylene glycol) have different concentrations depending on the product. Concentration of the ingested product must be known in order to estimate serum concentration.

    Formula

    [C] = Dose / (Vd × Weight); where:

    • [C] is serum concentration (mg/L).
    • Dose is amount ingested (mg).
    • Vd is volume of distribution (L/kg).
    • Weight is patient body weight (kg).

    Example: a 3-year-old boy (15 kg) ingests 30 mL of windshield washer fluid (50% methanol). Maximal predicted serum methanol concentration:

    • [C] = Dose / (Vd × Weight)
    • Dose:
      • 50% methanol = 50 g/100 mL = 500 mg/mL and
      • 500 mg/mL × 30 mL ingested = 15,000 mg methanol
    • [C] = 15,000 mg / (0.6 L/kg × 15 kg) = 1,667 mg/L
    • 1,667 mg/L × 1 L/10 dL = 167 mg/dL
      (a concentration requiring treatment with fomepizole)

    Example: a 21-year-old man (70 kg) ingests 750 mL of 15% wine. Maximal predicted serum ethanol concentration:

    • [C] = Dose / (Vd × Weight)
    • Dose:
      • 15% ethanol = 15 g/100 mL = 150 mg/mL and
      • 150 mg/mL × 750 mL ingested = 112,500 mg ethanol
    • [C] = 112,500 mg / (0.6 L/kg × 70 kg) = 2,679 mg/L
    • 2,679 mg/L × 1 L/10 dL = 268 mg/dL

    Facts & Figures

    To convert mg/dL to mmol/L:

    • Ethanol: divide ethanol concentration in mg/dL by 4.6
    • Methanol: divide methanol concentration in mg/dL by 3.2
    • Ethylene glycol: divide ethylene glycol concentration in mg/dL by 6.2
    Dr. Mary Ann Howland

    About the Creator

    Mary Ann Howland, PharmD, is an adjunct professor at the Ronald O. Perelman Department of Emergency Medicine at NYU Langone Health and a clinical professor at the College of Pharmacy and Health Sciences at St. John's University. She specializes in clinical toxicology, poison control, and clinical toxicological management. Dr. Howland's work has been published in many books and journals, including Goldfrank's Toxicologic Emergencies.

    To view Dr. Mary Ann Howland's publications, visit PubMed

    Content Contributors
    • Scott Lucyk, MD
    • Jonathan De Olano, MD
    About the Creator
    Dr. Mary Ann Howland
    Content Contributors
    • Scott Lucyk, MD
    • Jonathan De Olano, MD