Paraquat Poisoning: Immediate Decontamination and Early Treatment
For acute paraquat poisoning, immediately administer Fuller's Earth (or activated charcoal if Fuller's Earth unavailable) with cathartics to prevent absorption, and initiate hemoperfusion within 4 hours of ingestion to maximize survival. 1, 2
Immediate Decontamination Measures
Gastrointestinal Decontamination (First Priority)
Administer Fuller's Earth (calcium montmorillonite) or Bentonite (sodium montmorillonite) immediately at 60g orally, as these clay minerals strongly bind paraquat and prevent absorption 3, 2
If Fuller's Earth is unavailable, use activated charcoal at 1g/kg orally in a slurry, administered as quickly as possible 1, 2
Perform gastric lavage with 2.5% bicarbonate solution using small-volume, low-pressure manual technique, though evidence for efficacy is limited since peak plasma concentrations occur rapidly 4, 3
Administer cathartics (magnesium sulfate or polyethylene glycol electrolyte solution) to accelerate gastrointestinal transit and reduce absorption time 4, 2
Repeat Fuller's Earth/activated charcoal administration with cathartics once daily for 5 days to continue binding any remaining paraquat in the GI tract 4
Critical Timing Considerations
All decontamination measures are most effective within the first hour after ingestion, though benefit may extend to 3-4 hours 3, 5
Do NOT induce emesis or use ipecac, as paraquat is absorbed rapidly from the small intestine (peak levels within 1-6 hours) and vomiting delays definitive treatment 3
Avoid whole-gut lavage at high flow rates, as approximately 0.5-1.0 liters/hour may be absorbed across the intestinal wall, potentially increasing paraquat absorption 3
Early Treatment Strategies
Extracorporeal Elimination (Highest Priority)
Initiate hemoperfusion with coated activated charcoal within 4-6 hours of ingestion for maximum survival benefit 1, 6, 7
Perform "continuous hemoperfusion" for approximately 8 hours daily over 2-3 weeks, as this directly adsorbs paraquat from blood and tissues 1, 6
Combine hemoperfusion with continuous renal replacement therapy (CRRT) for synergistic effects on survival and sustained toxin removal 6, 7
Initiate continuous hemodiafiltration (CHDF) within 3-4 hours if hemoperfusion is unavailable, as this has shown successful outcomes in severe poisoning 7
Do NOT use hemodialysis (HD) as the primary detoxification method, as it appears ineffective for paraquat elimination and may increase mortality; reserve HD only for managing acute kidney injury 6
Supportive Care and Monitoring
Admit to ICU immediately for frequent monitoring and aggressive supportive care 5
Measure baseline plasma paraquat concentration to assess severity: <0.5 μg/mL suggests mild poisoning, 0.5-1.0 μg/mL indicates moderate-severe poisoning with high mortality risk 8
Avoid supplemental oxygen unless absolutely necessary (maintain PaO2 40-45 mmHg with hypoxic breathing mixtures if possible), as oxygen exacerbates paraquat-induced pulmonary toxicity through free radical generation 2
Monitor for multi-organ failure including renal dysfunction (BUN, creatinine), hepatic injury (ALT, bilirubin), pancreatic damage (amylase), and respiratory failure (PaO2) 4, 5
Immunosuppressive Therapy
Consider glucocorticoids with cyclophosphamide for moderate-to-severe poisoning, as low-certainty evidence suggests this may slightly reduce in-hospital mortality (RR 0.82,95% CI 0.68-0.99) when plasma paraquat levels are assessed at baseline 9
Weigh infection risk carefully, as evidence regarding infectious complications from immunosuppression is very limited 9
Clinical Severity Classification
Mild poisoning (<20 mg/kg): Gastrointestinal symptoms only; full recovery expected 5
Moderate-severe poisoning (20-40 mg/kg): Renal failure and delayed pulmonary fibrosis developing over days-weeks; majority fatal within 2-3 weeks 5
Acute fulminant poisoning (>40 mg/kg): Multiple organ failure within hours; death inevitable within days despite treatment 5
Critical Pitfalls to Avoid
Never delay hemoperfusion to wait for laboratory confirmation—clinical suspicion based on history and blue-green vomitus is sufficient to begin treatment 5, 8
Do not administer anything by mouth (including water or milk for dilution) unless specifically directed by poison control, as this may induce emesis and aspiration 10
Recognize that paraquat can be absorbed through damaged skin (including scrotal skin) and crosses the placental barrier, causing fetal death 8
Contact poison control centers immediately (1-800-222-1222 in US) for expert guidance on case-specific management 10