methanol intoxication
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Etiology
- ingestion of methanol
Epidemiology
- windshield washing fluid
- commercial solvents
- paints
- some antifreezes
- 2 teens die of Ingestion of a racing fuel* and carbonated soft drink mixture
* racing fuel is ~100% methanol
Pathology
- when ingested, methanol is rapidly metabolized to formaldehyde & to formic acid
- formic acid is slowly metabolized & causes the pathology
- major damage occurs at the retrolaminar optic nerve with intra-axonal swelling & organelle destruction
- little to no change is seen in the retina
- affects the basal ganglia; with severe intoxication, hemorrhagic & nonhemorrhagic damage of the putamen
Clinical manifestations
- metabolic acidosis
- central nervous system dysfunction
- optic disc congestion, papilledema
- mydriasis
- afferent pupillary defect
- pupillary response to light is compromised &, subsequently, is lost
- afferent pupillary defect
- complete blindness is common
- hypotension[1]
- abdominal pain, pancreatitis
- inebriation less prominent than with ethylene glycol
Laboratory
- anion gap metabolic acidosis
- arterial blood gas
- Chem7 or basic metabolic panel (calculate anion gap)
- serum Na+
- serum K+ (not used in calculation of anion gap)
- serum bicarbonate (< 10 meq/L)
- serum chloride
- serum osmolality, osmolal gap (> 10 mOsm/kg H2O)
- serum ketones are negative
- measurement of methanol in serum
- labs with Loincs
Complications
Differential diagnosis
- isopropanol intoxication does not show anion gap[1]
- ethylene glycol toxicity (renal manifestations)
Management
- fomepizole (Antizol) agent of choice[1]
- ethanol 10% solution
- hemodialysis
- blindness sometimes responds to therapy[2]
- sodium bicarbonate
- folic acid
More general terms
Additional terms
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15, 16, 17, 18. American College of Physicians, Philadelphia 1998, 2006, 2009, 2012, 2012, 2018.
- ↑ 2.0 2.1 eMedicine: Medicine http://www.emedicine.com/NEURO/topic217.htm
- ↑ Kruse JA Methanol and ethylene glycol intoxication. Crit Care Clin. 2012 Oct;28(4):661-711 PMID: https://www.ncbi.nlm.nih.gov/pubmed/2299899
- ↑ Fill MA, Seger DL, Dunn JR, Schaffner W, Jones TF. Notes from the Field: Intoxication and Deaths Associated with Ingestion of a Racing Fuel and Carbonated Soft Drink Mixture - Tennessee, January 2016. MMWR Morb Mortal Wkly Rep 2016;65:585-586 http://www.cdc.gov/mmwr/volumes/65/wr/mm6522a4.htm
- ↑ Kruse JA. Methanol and ethylene glycol intoxication. Crit Care Clin. 2012 Oct;28(4):661-711. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/22998995