What is the appropriate emergency management for acute paraquat ingestion?

Emergency Management of Acute Paraquat Ingestion

Immediately remove all contaminated clothing, thoroughly wash exposed skin with soap and water, contact poison control (1-800-222-1222), and begin gastrointestinal decontamination with activated charcoal or Fuller's earth—but critically, avoid supplemental oxygen unless SpO2 falls below 85%, as oxygen dramatically worsens paraquat toxicity through increased free radical production. 1, 2, 3

Immediate Decontamination (First Priority)

Rescuer Protection:

• Wear protective clothing and gloves before handling the patient, contaminated clothing, or body fluids to prevent secondary exposure 3
• Healthcare workers must use appropriate personal protective equipment when managing these patients 2

Patient Decontamination:

• Remove all contaminated clothing and jewelry immediately to prevent continued dermal absorption 1, 2
• Thoroughly wash all exposed skin areas with soap and water 1, 3
• In pediatric patients, use warmed shower water at lower pressure with heat lamps and blankets to prevent hypothermia 1

Gastrointestinal Decontamination (After Airway Protection)

The American College of Medical Toxicology recommends against routine gastric lavage for paraquat poisoning. 1 Instead:

• Administer multiple-dose activated charcoal (15-20g every 6 hours) or Fuller's earth as the preferred decontamination method 1, 3, 4
• These agents work through adsorption rather than mechanical removal 1
• Critical caveat: Only perform gastrointestinal decontamination after securing the airway and achieving hemodynamic stability 1, 3
• Never delay airway protection to perform decontamination, as aspiration risk is significant 1

Oxygen Management (Uniquely Critical in Paraquat)

This is the most important pitfall to avoid in paraquat poisoning:

• Target oxygen saturation of 85-88%, which is dramatically lower than standard critical care targets 1, 2, 3
• Administer supplemental oxygen ONLY if SpO2 falls below 85% 1, 2, 3
• Reduce or stop oxygen therapy if saturation rises above 88% 1, 2, 3
• Rationale: Oxygen accelerates paraquat-induced lung injury by increasing free radical production and worsening pulmonary fibrosis 1, 2, 3, 5
• This represents a unique exception to standard resuscitation protocols 2

Supportive Care and Monitoring

Airway and Hemodynamics:

• Provide standard airway management if respiratory distress develops 2
• Treat hypotension and dysrhythmias according to standard protocols 2
• Administer benzodiazepines for seizures or severe agitation 2

Poison Control Consultation:

• Contact poison control centers immediately (1-800-222-1222 in the United States) for expert guidance 6, 2, 3
• Maintain continuous contact for evolving treatment recommendations 1, 2

Prognostic Assessment

Key prognostic indicators:

• Plasma paraquat concentration is the most important prognostic indicator 4
• Volume ingested (>30 mL associated with severe toxicity) 7
• Presence of caustic burns in the upper digestive tract indicates worse prognosis 4
• PF ratio <100 indicates severe respiratory compromise 7

Advanced Therapies (Controversial, Limited Evidence)

While the prognosis remains uniformly poor despite aggressive treatment 8, some case reports suggest potential benefit from:

• Early hemodialysis or hemoperfusion to enhance elimination 9, 4
• Antioxidant therapy including deferoxamine (100 mg/kg/24h) and continuous acetylcysteine infusion (300 mg/kg/day) 9
• However, these interventions lack clear evidence of improved survival rates 4
• Lung transplantation has been reported in select survivors after complete paraquat depletion (urine paraquat negative, typically >30 days) 7

Common Pitfalls to Avoid

• 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 delay airway protection to perform gastrointestinal decontamination 1
• Do NOT administer anything by mouth unless advised by poison control 6

Expected Clinical Course

Paraquat accumulates primarily in lung tissue (6-10 times higher than plasma concentrations) where it causes diffuse alveolitis followed by extensive pulmonary fibrosis 4, 5. Death typically occurs within 2 days of ingesting 50 mg/kg, though at lower doses death may be delayed for several weeks 4. Multi-organ failure affecting lungs, kidneys, liver, heart, and GI tract is common 8, 5.