Paraquat poisoning

Paraquat is a bipyridyl herbicide; even small ingestions of 20% concentrate (Gramoxone) are commonly fatal. Toxicity is from redox cycling generating superoxide → ARDS and progressive pulmonary fibrosis; also AKI, hepatic necrosis, cardiovascular collapse. Features: oropharyngeal pain and ulceration (early), vomiting, abdominal pain, AKI within 24 h, ALT/AST rise, refractory hypotension; pulmonary fibrosis develops over 1–2 weeks ("paraquat lung"). ABCDE; large-bore IV access; bloods inc. paraquat level (urgent — guides prognosis), U&E, LFTs, VBG, lactate, FBC, paracetamol/salicylate. Urine dithionite test (turns blue if positive — bedside screen). PSYCHOLOGICAL: counsel patient honestly; survival likelihood from level + time (Proudfoot nomogram) — most ingestions of >10–20 mL of 20% are fatal.