Emergency Management of Acute Paraquat Poisoning
Immediately remove all contaminated clothing, thoroughly wash exposed skin with soap and water, secure the airway, and contact poison control—then administer multiple-dose activated charcoal (15-20g every 6 hours) only after hemodynamic stabilization, while strictly limiting oxygen supplementation to maintain SpO2 between 85-88% only. 1, 2, 3
Immediate Decontamination (First Priority)
Remove contaminated clothing and jewelry immediately to prevent continued dermal absorption, as paraquat continues to be absorbed through contaminated skin. 2, 3 Healthcare workers must wear gloves and protective clothing when handling the patient or any contaminated materials to prevent secondary exposure. 2, 3
Thoroughly wash all exposed skin areas with soap and water using warmed water at lower pressure in pediatric patients to prevent hypothermia. 1, 2 This step is critical as contaminated skin, clothing, and body fluids can cause secondary exposure. 1
Gastrointestinal Decontamination
Administer multiple-dose activated charcoal (15-20g every 6 hours) as the preferred decontamination method, but only after securing the airway and achieving hemodynamic stability. 1, 3 The American College of Medical Toxicology specifically recommends against routine gastric lavage for paraquat poisoning. 1
Fuller's earth or activated charcoal work through adsorption of the toxin and are superior to mechanical gastric lavage. 1 Never attempt decontamination without first ensuring airway protection, as aspiration risk is significant and can be catastrophic. 1
Critical Oxygen Management (Unique to Paraquat)
This is the most critical pitfall to avoid: Do not provide supplemental oxygen liberally. 1, 2, 3 Paraquat toxicity is dramatically worsened by high oxygen concentrations through increased free radical production. 1, 2, 3
Target oxygen saturation of 85-88%, which is significantly lower than typical critical care targets. 1, 2, 3 The British Thoracic Society specifically recommends:
- Administer oxygen only if SpO2 falls below 85% 1, 2, 3
- Reduce or stop oxygen if saturation rises above 88% 1, 2, 3
Oxygen accelerates paraquat-induced lung injury by increasing free radical production and worsening pulmonary fibrosis. 1, 3
Supportive Care and Monitoring
Contact poison control centers immediately for expert guidance and maintain continuous contact for evolving treatment recommendations. 1, 2, 3 This is essential as paraquat poisoning requires specialized management.
Provide standard supportive care including:
- Airway management if respiratory distress develops 2, 3
- Treatment of hypotension and dysrhythmias according to standard protocols 2
- Benzodiazepines for seizures or severe agitation if they occur 2
- Fluid and electrolyte replacement for hypovolemia 4
Prognostic Assessment
The plasma paraquat concentration is the most important prognostic indicator, as it reflects the quantity absorbed. 5 The prognosis is uniformly poor worldwide, with mortality rates up to 43% in reported cases. 6, 4 Severe cases develop gastrointestinal mucosal ulceration, paralytic ileus, hypovolemic shock, acute renal failure, and multisystem organ failure. 4, 7
Experimental Therapies (Limited Evidence)
Some centers have reported survival with immunosuppression using cyclophosphamide and methylprednisolone pulse therapy, though evidence is limited to case series. 7 Antioxidant therapy with deferoxamine (100 mg/kg in 24 hours) and continuous acetylcysteine infusion (300 mg/kg/day for 3 weeks) has been reported in survival cases, but lacks controlled trial evidence. 8
There are no specific antidotes and none of the current treatments have proven efficacy in controlled trials. 6, 5
Common Pitfalls to Avoid
- Do not delay airway protection to perform gastrointestinal decontamination 1
- Do not provide supplemental oxygen liberally—this is uniquely harmful in paraquat toxicity 1, 2, 3
- Do not use gastric lavage routinely when activated charcoal is the evidence-based alternative 1
- Do not forget personal protective equipment for healthcare workers to prevent secondary exposure 2, 3