What is the emergency management for acute paraquat ingestion?

Emergency Management of Acute Paraquat Ingestion

Immediately activate emergency medical services and contact poison control (800-222-1222 in the US) for expert guidance, as paraquat ingestion carries extremely high mortality and requires specialized management protocols. 1, 2

Immediate Safety and Decontamination

Provider Protection

• Wear gloves and full protective equipment when handling the patient, their clothing, or bodily fluids, as paraquat can be absorbed through skin or respiratory tract 3, 2
• Remove all contaminated clothing and jewelry immediately to prevent continued dermal absorption 2, 4

Skin Decontamination

• Thoroughly wash all exposed skin areas with soap and water to prevent secondary exposure 2, 4
• In pediatric patients, use warmed shower water at lower pressure with heat lamps and blankets to prevent hypothermia 4

Gastrointestinal Decontamination

• Do NOT induce vomiting or administer ipecac—this is contraindicated due to aspiration risk 3, 1
• Do NOT give water or milk to dilute the poison—this provides no proven benefit and may provoke emesis 3, 1
• Consider multiple-dose activated charcoal (15-20g every 6 hours) or Fuller's earth ONLY after securing the airway and achieving hemodynamic stability 4, 5
• Do not perform routine gastric lavage; activated charcoal is the evidence-based alternative 4

Critical Oxygen Management (Unique to Paraquat)

This is the most critical pitfall to avoid: paraquat toxicity is dramatically worsened by supplemental oxygen through increased free radical production. 2, 4

• Administer oxygen ONLY if SpO2 falls below 85% 2, 4
• Target oxygen saturation of 85-88%—significantly lower than typical critical care targets 2, 4
• Reduce or stop oxygen if saturation rises above 88% 2, 4
• This restrictive oxygen strategy is based on British Thoracic Society recommendations and is essential to prevent accelerated lung injury 2, 4

Supportive Care and Monitoring

• Provide standard airway management if respiratory distress develops, but only after considering the oxygen restrictions above 2
• Treat hypotension and dysrhythmias according to standard protocols 2
• Administer benzodiazepines for seizures or severe agitation if they occur 2
• Maintain continuous contact with poison control center for evolving treatment recommendations 2, 4

Advanced Treatment Considerations

Extracorporeal Removal

• Early hemoperfusion is strongly suggested by evidence, though survival remains poor overall (26.4% in large cohort) 6
• The average frequency of hemoperfusion is twice per patient 6

Immunosuppressive Therapy

• Adding immunosuppressive treatment to hemoperfusion improves survival from 24.3% to 29.3% 6
• The combination of methylprednisolone, cyclophosphamide, and dexamethasone associates with the highest survival rate (48%) 6
• This benefit is most pronounced in patients younger than 45 years of age (41.0% vs 33.7% survival) 6

Antioxidant Therapy

• Consider deferoxamine (100 mg/kg in 24 hours) and continuous infusion of acetylcysteine (300 mg/kg/day for 3 weeks) as adjunctive therapy 7
• While case reports suggest benefit, these remain experimental treatments without definitive evidence 7, 5

Prognostic Indicators

• The plasma paraquat concentration is the most important prognostic indicator 5
• Absence of caustic burns in the upper digestive tract indicates better prognosis 5
• Respiratory failure occurs in 56.2% and renal failure in 36% of hospitalized patients 6

Psychiatric Evaluation

• All patients with intentional paraquat ingestion must receive psychiatric evaluation before discharge 3

Common Pitfalls to Avoid

• Never delay airway protection to perform gastrointestinal decontamination 4
• Never provide supplemental oxygen liberally—this is uniquely harmful in paraquat toxicity 2, 4
• Never attempt decontamination without first ensuring airway protection due to significant aspiration risk 4
• Do not waste time with gastric lavage when activated charcoal is available and more effective 4, 1