Methanol Ingestion With No Fomepizole and One Dialysis Machine
A 38-year-old man is brought 6 hours after drinking approximately 300 mL of industrial alcohol at a workshop. He complains of nausea, abdominal pain, and blurred vision. He appears mildly intoxicated but is alert. Vitals: HR 118, BP 118/70, RR 24, SpO2 98%, temperature 36.5°C. Fundoscopy is normal; visual acuity is reduced to counting fingers bilaterally. Arterial blood gas: pH 7.25, PaCO2 28 mmHg, PaO2 95 mmHg, HCO3 12 mmol/L. Sodium 138, potassium 3.4, chloride 98, creatinine 90 µmol/L, glucose 6.1 mmol/L. Anion gap 28, osmol gap 42. Serum ethanol is 18 mg/dL. The hospital pharmacy has no fomepizole and cannot obtain it before morning. Ethanol for intravenous infusion is available. One haemodialysis machine is running on a stable chronic patient and will be free at 08:00; it is now 02:00. The regional poison centre is reachable by phone.
1. What is your immediate management, including the choice of alcohol dehydrogenase blockade?
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This is severe methanol poisoning with visual symptoms and a high-anion-gap metabolic acidosis. Treatment cannot wait for a methanol level. The key steps are:
- Airway and monitoring: he is alert but at risk of deterioration. Obtain IV access, monitor cardiac rhythm, and check glucose and electrolytes repeatedly.
- Alcohol dehydrogenase blockade: fomepizole is first choice but is unavailable, so start intravenous ethanol. Give a loading dose of 0.6–0.8 g/kg over 30–60 minutes, then 0.1–0.15 g/kg/hour, targeting a serum ethanol concentration of 100–150 mg/dL. Ethanol is not a perfect drug: it causes intoxication, hypoglycaemia, and phlebitis, and requires frequent monitoring, but it prevents further formation of formate.
- Sodium bicarbonate: give 1–2 mmol/kg IV boluses for pH below 7.3, targeting 7.35–7.45. This treats the acidosis and reduces formate penetration into the retina and brain.
- Folinic acid: 50 mg IV every 6 hours to enhance formate metabolism.
- Supportive care: thiamine 100 mg, magnesium and potassium replacement, and careful fluid balance.
Activated charcoal is not useful at 6 hours because methanol is rapidly absorbed. I would call the poison centre to confirm dosing and to help arrange dialysis.
2. Does this patient need haemodialysis, and how do you decide who gets the single machine?
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Yes. He has at least three accepted indications for haemodialysis: visual symptoms, severe metabolic acidosis with pH 7.25, and a large ingestion with a high osmol gap. A methanol level above 50 mg/dL would be another indication, but treatment should not wait for it.
Dialysis removes methanol and, more importantly, formate, and corrects the acidosis. It is the definitive treatment for severe poisoning. The single machine should go to this patient because his condition is time-critical and potentially blinding or fatal. The stable chronic dialysis patient can safely wait until after this emergency; I would speak to the nephrologist and document the triage decision. If the machine cannot be freed, I would arrange urgent transfer to another dialysis-capable hospital after starting ethanol and bicarbonate.
During dialysis, ethanol is also removed, so the ethanol infusion must be increased and the level checked frequently. I would continue bicarbonate and folinic acid and monitor potassium, calcium, and glucose. Dialysis should continue until the acidosis has resolved and the methanol level is low, not simply until the patient feels better.
3. At 06:00 he says he feels much better, his vision has improved, and he wants to leave. His repeat pH is 7.38. Do you stop ethanol and discharge him?
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No. Clinical improvement does not mean the poisoning is over. Formate can continue to cause delayed metabolic and visual toxicity, and acidosis can rebound after bicarbonate is stopped. A normal pH at one moment does not exclude ongoing methanol metabolism.
I would continue ethanol until the methanol concentration is below about 20–25 mg/dL, the acidosis has resolved, and he is clinically stable and asymptomatic. I would repeat the osmol gap, electrolytes, and blood gas. If dialysis is still indicated, I would complete it. I would not discharge him from the emergency department; he needs admission and monitoring.
If he insists on leaving, I would assess decision-making capacity. He has received ethanol, so he may be intoxicated and lack capacity. I would explain the risks of blindness, renal failure, and death in clear terms, involve his family if appropriate, document the discussion, and arrange psychiatric assessment. A patient who lacks capacity and has a life-threatening but treatable condition can be treated under emergency provisions, with senior and legal advice if needed.