Paraquat Poisoning — Management Pathway

Step-by-step decision

Choose step by step as prompted; reaching an endpoint gives the management recommendation. You can go back a step or restart anytime.

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Full pathway

1. [Decision] Is oxygen needed (the key paradox)
   What is the oxygenation status? (Paraquat is a highly toxic herbicide (common in Asia, very high mortality, no specific antidote) that causes lung (pneumonitis → fibrosis), kidney and liver injury via redox cycling. Its toxicity is worsened by high-concentration oxygen (promotes oxygen free radicals/lipid peroxidation) — this is the most common mistake. Staff use PPE (gloves, gown), remove contaminated clothing.)
   • SpO2 ≥85–88% → Avoid oxygen + decontaminate
   • SpO2 <85% (severe hypoxemia) → Severe hypoxemia (minimal oxygen)
2. [End] Avoid oxygen + decontaminate
   Avoid oxygen (the lethal paradox): give oxygen only if SpO2 <85%, targeting a low SpO2 of 85–88%, and reduce/stop above 88%. Also: 1) Early oral activated charcoal or Fuller's earth adsorption (no gastric lavage). 2) Early hemoperfusion (charcoal) for removal — as early as possible in moderate-severe cases, may be several hours daily for 2–3 weeks. 3) Immunosuppression (cyclophosphamide + methylprednisolone/dexamethasone pulse) has weak evidence and may be considered in moderate-severe cases; antioxidants (NAC, vitamin C) are unproven. 4) Prognosticate by ingested dose and blood/urine paraquat level, supportive care, contact a poison center.
3. [End] Severe hypoxemia (minimal oxygen)
   Severe hypoxemia (SpO2 <85%): give the minimum necessary oxygen to maintain SpO2 ~85–88% (never over-oxygenate), otherwise the same as the main pathway — activated charcoal/Fuller's earth adsorption, early hemoperfusion, (moderate-severe) immunosuppression, supportive care, prognosticate by ingested dose/blood level, contact a poison center.

Source guidelines & references

• Paraquat poisoning management review (Gawarammana & Buckley, et al.)
• Consensus on acute paraquat poisoning management and blood purification

This pathway is our own synthesis of the decision logic in the guidelines above (not the guideline verbatim); thresholds and workflows change as guidelines update — in practice follow the latest guideline, your institution's protocol and the individual patient.

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