What is the treatment for paraquat poisoning?

Treatment for Paraquat Poisoning

For paraquat poisoning, immediate supportive care and decontamination are essential, while avoiding supplemental oxygen unless absolutely necessary with a target saturation of 85-88% to prevent worsening lung injury.

Initial Management

• Ensure rescuer safety by wearing protective clothing and gloves to prevent direct skin contact and inhalation of toxic fumes when handling the victim's clothes or body fluids, especially vomit 1
• Seek advice from poison information centers immediately for guidance on specific treatment 1
• Provide supportive care with focus on airway management, hemodynamic support, and correction of metabolic derangements 1

Decontamination Measures

• Remove contaminated clothing and thoroughly wash exposed skin areas 1
• For ingestion, perform gastric lavage if the patient presents early (within hours of ingestion) 2
• Administer activated charcoal to prevent further absorption 2
• Consider multiple-dose activated charcoal (15-20g every 6 hours) only after airway protection and hemodynamic stabilization 1

Oxygen Management - Critical Consideration

• Avoid supplemental oxygen unless oxygen saturation falls below 85%, and reduce or stop oxygen therapy if saturation rises above 88% 1
• Target oxygen saturation of 85-88% as paraquat toxicity is worsened by high oxygen concentrations 1
• Oxygen can increase paraquat-induced free radical production and worsen lung injury 1

Extracorporeal Elimination

• Consider hemoperfusion with activated charcoal, especially if initiated within the first hours after ingestion 2, 3
• Implement hemodialysis for removal of paraquat and management of acute kidney injury 2, 4
• Early initiation of extracorporeal treatments may improve outcomes in severe cases 5

Pharmacological Interventions

• Consider pulse steroid therapy (methylprednisolone) and cyclophosphamide to reduce inflammatory response and pulmonary fibrosis 3, 5
• Provide anticoagulation therapy to prevent thrombotic complications 5
• Administer medications for liver and kidney protection 5

Monitoring and Follow-up

• Monitor for multiple organ dysfunction, particularly respiratory, renal, and hepatic failure 2, 4
• Assess severity based on estimated amount ingested:
  • Mild poisoning (<20 mg/kg): Generally good prognosis 6
  • Moderate-severe poisoning (20-40 mg/kg): High mortality with delayed death due to pulmonary fibrosis 6
  • Fulminant poisoning (>40 mg/kg): Rapid multiple organ failure with death within hours to days 6
• Continue long-term follow-up as pulmonary fibrosis may develop or worsen even after initial recovery 5

Prognosis

• Prognosis depends on the amount ingested, route of exposure, and time to treatment 6
• Intravenous exposure has worse prognosis than oral ingestion due to faster development of toxic effects 3
• Even minimal dermal exposure can be fatal in some cases 4
• Mortality is extremely high in moderate to severe poisoning despite optimal management 2

Important Caveats

• The route of exposure affects the clinical course - intravenous exposure leads to more rapid toxicity than oral ingestion 3
• Pulmonary damage may worsen when glucocorticoid treatment is discontinued, requiring careful monitoring and potential retreatment 5
• Paraquat concentrations >50 mg/L are often fatal despite aggressive treatment 2
• Successful treatment of severe paraquat poisoning is rare, emphasizing the importance of prevention and early intervention 5