Early Hemodialysis in Methanol Poisoning Without Severe Acidosis or End-Organ Damage: A Case for Preemptive Intervention

Introduction: Methanol is an alcohol found in household and industrial products. While not inherently toxic, its hepatic metabolites—formaldehyde and formic acid—are highly toxic. As little as 15 mL can cause severe toxicity, including vision loss, coma, and death. Symptoms include visual changes, metabolic acidosis, CNS depression, and seizures. Treatment involves fomepizole and hemodialysis. Dialysis is generally reserved for methanol >50 mg/dL, severe acidosis, AKI, visual changes, or hemodynamic instability. Case Description: An 82-year-old female with dementia presented after potential ingestion of methanol-containing gel fuel. She was asymptomatic, with pH 7.34, anion gap 15, osmolality 321 mOsm/kg H2O, and osmolal gap 25. Salicylate and ethanol levels were undetectable. Methanol level was sent but not immediately available. Given high clinical suspicion and elevated osmolal gap, fomepizole was started. Despite the absence of acidosis or organ dysfunction, early hemodialysis was initiated. After dialysis, the osmolal gap dropped to 4. Methanol level returned two days later at 55 mg/dL. Discussion: This case emphasizes the value of early hemodialysis in methanol poisoning, even without classic indications. Most hospitals lack timely methanol testing, risking treatment delay. Around 5,000 U.S. cases are reported annually. Exposure may be via ingestion, inhalation, or dermal contact. Toxicity arises from formic acid, causing tissue hypoxia and acidosis. An early osmolal gap and later anion gap may guide diagnosis. These depend on exposure timing. Gas chromatography is confirmatory but often delayed. Fomepizole blocks metabolism but prolongs methanol’s half-life to over 50 hours. Hemodialysis rapidly clears methanol and formate, reducing toxicity and hospitalization. While randomized trials are lacking, early use with fomepizole may improve outcomes, especially in high-risk cases.