Case #2 Toxin and Discussion

QUESTIONS and CONTROVERSIAL ISSUES

What is this patient's anion gap?

Na -(Cl + HCO3) NL= 8-12

145 - (105 + 5) = 35

II) What is the differential for a patient with an elevated anion gap acidosis?

• A= Alcoholic ketoacidosis
• C= Cyanide, Carbon monoxide
• A= ASA (salicylates)
• T= Toluene

• M= Methanol
• U= Uremia
• D= DKA
• P= Paraldehyde
• I= INH, Iron
• L= Lactic acidosis
• E= Ethylene glycol

III) What is the patients osmol gap? Differential?

• 2(Na) + Glucose/18 + BUN/2.8 + ETOH/4.6
• 290 + 10 + 10 + 10 = 320

The osmol gap is the difference between the measured and calculated osmol (normal less than 10): 370 - 320 = 50

Differential:

• M= Methanol
• E= Ethanol
• D= Diuretics
• I= Isopropanol
• E= Ethylene glycol

IV) What urine tests may assist the clinician in establishing this patient's poison?

• A) Urinary calcium oxalate crystals with ethylene glycol
• B) "Wood's Lamp test"

V) While awaiting the toxic alcohol results (methanol, ethylene glycol, isopropanol) what therapeutic interventions are essential in the management of this patient?

• Correction of acidosis with sodium bicarbonate

• Ethanol- competitively binds to alcohol dehydrogenase

Indications:

• Suspicion for toxic alcohol ingestion
• Methanol/Ethylene glycol levels over 20mg/dl

Goal: Ethanol levels of 100-150 mg/dl

Renal consult for hemodialysis

Indications:

• Metabolic acidosis not responsive to bicarb
• Eye findings (methanol)
• Renal failure/pulmonary edema (ethylene glycol)
• Peak serum levels > 50mg/dl

VI) Is there an antidote available for the toxic alcohols?

4-Methylpyrazole: direct alcohol dehydrogenase inhibitor Currently available in Europe Substitute for ethanol therapy, may circumvent need for hemodialysis Clinical investigations underway in U.S. (awaiting FDA approval)