FM13.15 | Agrochemical & Pesticide Poisoning — Summary & Reflection

KEY TAKEAWAYS

Pesticide poisoning (FM13.15) is dominated by six agents with distinct mechanisms:

• Organophosphates: AChE inhibition → SLUDGE + fasciculations + miosis. Antidote: atropine (no time limit) + pralidoxime within 24–48 h (before ageing). Intermediate syndrome: delayed respiratory paralysis, no antidote beyond ventilatory support.

• Carbamates: reversible AChE inhibition, shorter duration; atropine only (no PAM needed).

• Organochlorines/pyrethroids: Na⁺ channel prolongation → excitatory toxidrome (tremor, seizures). Benzodiazepines; no specific antidote.

• Paraquat: superoxide redox cycling → pulmonary fibrosis. Oxygen CONTRAINDICATED. Charcoal only within 2 h. No antidote.

• Aluminium/zinc phosphide: phosphine gas → cytochrome oxidase inhibition + direct cardiotoxicity. Garlic/rotten fish smell. No antidote — supportive only.

Medicolegal documentation must include toxidrome identification, AChE activity, analytical toxicology specimens, and chain-of-custody for the exhibit container.

REFLECT

The nurse in the hook scenario gave high-flow oxygen to the paraquat patient — a potentially fatal error made with genuinely good intentions. As the treating forensic medicine specialist (who may later be called to testify), how would you document this clinical event in a way that is accurate, protects the patient's legal rights, and is fair to the nurse? More broadly, how should a district hospital update its pesticide poisoning protocol to prevent the same error from occurring in the next case — and what training intervention would you recommend?