Normoxic or hypoxic conditions associated with better survival
Avoid routine oxygen even in early course
Immunosuppression rationale
Inflammatory component of lung injury
Oxidative stress triggers inflammatory cascade
Steroids suppress inflammatory amplification
Cyclophosphamide reduces fibroblast proliferation
Evidence base
Meta-analyses suggest 25% relative reduction in mortality
Taiwanese cohort with combination therapy: 48% survival versus historical controls
Evidence quality low due to lack of RCTs
Antioxidant strategy rationale
Reducing oxidative damage
N-acetylcysteine replenishes glutathione
Deferoxamine chelates iron reducing hydroxyl radical production
Combination may have additive benefit
Prevention of fibrosis
Pirfenidone inhibits TGF-beta mediated fibrosis
Anti-fibrotic therapy emerging as adjunct
Futility and goals of care
Prognosis communication
Fulminant poisoning with dose > 40 mg/kg near universally fatal
Early goals of care discussion appropriate
Palliative care involvement for severe cases
Patient Discharge Instructions
copy discharge instructions
Paraquat poisoning discharge care
Strict compliance with follow-up appointments
Lung function testing as scheduled
Kidney function blood tests as ordered
No gardening or agricultural chemical exposure
Avoid all herbicide contact
Use full PPE if occupational exposure unavoidable
Medications as prescribed
Complete all tapering steroid doses as directed
Do not stop medications without speaking to your doctor
Warning signs to return to emergency immediately
Shortness of breath or breathing difficulty
Even mild breathlessness requires evaluation
Lung injury can worsen days to weeks after exposure
Chest tightness or pain
Decreased urine output or no urine
Yellow skin or eyes (jaundice)
Severe mouth or throat pain worsening
Confusion, extreme weakness, or fainting
Coughing up blood
Mental health support
Psychiatric follow-up appointment
If the ingestion was intentional
Contact mental health crisis line if thoughts of self-harm return
Safe storage of all chemicals
Remove access to herbicides and pesticides from home
Involve family or support person in safety plan
Recovery expectations
Lung injury may continue to develop for 2 weeks
Even if feeling better, monitoring continues
Report any new breathing symptoms promptly
Kidney function recovery takes weeks to months
Long-term pulmonary function testing will determine extent of lung damage
References
Guidelines and key sources
Toxicology and poison control references
WHO paraquat poisoning management guidelines
UpToDate: Paraquat and diquat poisoning clinical review
Proudfoot AT, Stewart MS et al: Paraquat poisoning: significance of plasma-paraquat concentrations. Lancet 1979
Key clinical studies
Lin JL, Liu L et al: Pulse therapy with cyclophosphamide and methylprednisolone in paraquat poisoning. Taiwan series n=1811 demonstrating 48% survival with combination protocol
Lin NC et al: Prognostic index for paraquat poisoning: AUC 0.921 for six-variable composite score predicting death
Lee SY et al: Serial CT lung volume fraction ratio as prognostic marker with ratio < 0.3 universally fatal and > 0.8 all survived
Pharmacologic evidence
Meta-analysis of immunosuppressive therapy in paraquat poisoning: 60.4% versus 85.3% mortality controls
N-acetylcysteine case reports with favorable outcomes in paraquat poisoning
Pirfenidone pediatric case report with 6-month follow-up survival
Coding standards
ICD-10 T60.3 toxic effect of herbicides and fungicides
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.