Paraquat poisoning is very severe. When it is ingested, this
herbicide may be responsible for causative lesions of the digestive tract, cytolytic
hepatitis, renal tubular
necrosis,
circulatory failure, and/or
pulmonary fibrosis. Since a very low dose (as little as one mouthful) is potentially lethal, it is important to understand why 11 of our 28 patients who entered our department for
paraquat poisoning survived. The main prognostic factors appear to be the following: Route of administration. Of four patients who had inhaled
paraquat aerosols and/or contaminated their skin with the
herbicide, all survived. Ingested amount. Above 50 mg/kg, patients died of
circulatory failure within 72 h; between 35 and 50 mg/kg, a progressive
pulmonary fibrosis occurred. Delay between ingestion and the last meal.
Paraquat is adsorbed and neutralized by foodstuffs.
Caustic gastric lesions revealed by early endoscopic examination. The occurrence of an organic
renal failure. The plasma
paraquat concentrations within the first 24 h. Patients whose plasma concentrations do not exceed 2.0, 0.6, 0.3, 0.16, and 0.1 mg/L at 4, 6, 10, 16, and 24 h, respectively, are likely to survive. The different treatments that have been tested (
fuller's earth, forced
diarrhea,
furosemide,
hemodialysis,
hemoperfusion, artificial ventilation with hypoxic breathing mixtures) did not modify the initial prognosis. The 11 survivals are only linked to the circumstances of the
poisonings (route of administration, ingested amount, delay between ingestion and the last meal, etc.). The treatments did not modify the outcome.