Hemodialysis is NOT Effective for Paraquat Poisoning and Should NOT Be Used
Hemodialysis does not improve survival in paraquat poisoning and should not be performed, as it fails to prevent death despite efficiently clearing paraquat from plasma, because the toxin rapidly distributes into tissues where it causes irreversible damage. 1, 2, 3
Why Hemodialysis Fails in Paraquat Poisoning
The Fundamental Problem: Tissue Distribution vs. Plasma Clearance
- Paraquat rapidly concentrates in tissues (especially lungs) within hours of ingestion, making plasma removal ineffective. 1
- Autopsy data from treated patients show persistently elevated tissue paraquat levels (lung 4.0 μg/g, skeletal muscle 9.4 μg/g, kidney 3.1 μg/g) despite aggressive hemodialysis that achieved blood clearances of 151 ml/min. 1
- The toxin is actively transported against concentration gradients into lung tissue, where it causes pneumonitis and fibrosis that hemodialysis cannot prevent. 4
Evidence Against Hemodialysis Efficacy
- A 2022 systematic review and meta-analysis of 203 patients demonstrated that hemodialysis was associated with HIGHER mortality (OR 2.84,95% CI: 1.22-6.64, p=0.02) compared to no hemodialysis. 2
- A retrospective review of 42 paraquat-poisoned patients showed that hemoperfusion and hemodialysis did not affect survival when compared to predicted outcomes based on plasma concentrations. 3
- No patient with initial plasma paraquat concentrations >3 mg/L survived regardless of hemodialysis use, timing, or duration. 3
The Rebound Phenomenon
- Even when hemodialysis efficiently removes paraquat from blood, only a "limited rebound" of blood levels occurs post-dialysis, confirming that the peripheral tissue compartment remains the primary reservoir of toxin. 1
- This demonstrates that removing circulating paraquat does not address the tissue-bound toxin causing organ damage. 1
What This Means for Clinical Practice
Do NOT Initiate Hemodialysis
- Hemodialysis should not be performed for paraquat removal, as it provides no survival benefit and subjects patients to unnecessary morbidity, discomfort, and cost. 3
- The procedure may still be needed for managing acute kidney injury complications, but not for toxin removal. 5, 4
Contrast with Other Poisonings
- Unlike salicylate or ethylene glycol poisoning where hemodialysis is strongly recommended and effective 6, paraquat's rapid tissue distribution and active cellular uptake make extracorporeal removal futile. 1, 3
- Current guidelines for extracorporeal treatment of poisonings do not include paraquat as an indication. 6
Prognostic Indicators
- Plasma paraquat concentration and time post-ingestion are the primary determinants of survival, not treatment modality. 3
- Patients with lethal dose ingestion (>3 mg/L) have uniformly fatal outcomes despite any intervention. 3
Focus on Supportive Care
- Gastric lavage and activated charcoal within hours of ingestion remain the only potentially beneficial interventions. 5
- Immunosuppressive regimens (cyclophosphamide + corticosteroids) have been reported in case studies but lack robust evidence. 5
- Supportive care for multi-organ failure (renal, hepatic, pulmonary) is the mainstay of management. 4
Critical Pitfall to Avoid
Do not delay or withhold other supportive measures while pursuing hemodialysis, as this wastes critical time without providing benefit and may worsen outcomes through procedure-related complications. 3