IM22.{1,5} | Poisoning Stabilisation and Toxidromes — Summary & Reflection

KEY TAKEAWAYS

Acute poisoning management begins with systematic ABC stabilisation: secure the airway (intubate at GCS ≤8 or absent gag reflex), optimise breathing (high-flow oxygen; recognise respiratory depression patterns), establish IV access and manage circulation (fluids, haemodynamic support), assess GCS and pupils, check bedside glucose, and remove all contaminated clothing.

Key investigations: blood glucose, ABG with anion gap and osmolar gap, ECG, renal/liver function, and specific drug levels where actionable.

Five toxidromes and their antidotes:
- Cholinergic (OP/carbamate): SLUDGE + miosis + bradycardia + fasciculations → Atropine + Pralidoxime
- Anticholinergic (Datura, TCAs, antihistamines): dry, flushed, mydriasis, delirium, urinary retention → Supportive; physostigmine selectively
- Sympathomimetic (cocaine, amphetamines): tachycardia, hypertension, hyperthermia, diaphoresis, mydriasis → Benzodiazepines; cooling
- Opioid (tramadol, morphine, codeine): miosis + respiratory depression + coma → Naloxone
- Sedative-hypnotic (benzodiazepines, barbiturates): CNS depression, near-normal pupils, no secretions → Flumazenil (BZD only; caution)

Decontamination: activated charcoal 50 g (within 1–2 hours; not for corrosives, iron, alcohols); gastric lavage rarely; dermal decontamination (remove clothing + wash). Enhanced elimination: urinary alkalinisation (salicylates), haemodialysis (methanol, ethylene glycol, severe salicylate, lithium).

Antidote matching (all IM known-traps): paracetamol → NAC (Rumack-Matthew nomogram); methanol/ethylene glycol → fomepizole or ethanol; iron → desferrioxamine; warfarin → vitamin K + PCC/FFP; beta-blocker → glucagon; digoxin → Fab fragments.

REFLECT

Recall the two patients in the opening hook — one drenched and bradycardic (cholinergic), one dry and feverish (anticholinergic). Both were unconscious; both looked critically ill. The only tool you had in the first 60 seconds was pattern recognition. Now that you have worked through this module, practise mapping each toxidrome onto the clinical features mentally without looking at the table. Can you recall the pupil response, skin characteristics, and vital sign pattern for all five toxidromes from memory? Think about the rural hospital setting where you will rotate: no toxicology screen, delayed specialist availability, limited antidote stock. Which two antidotes would you consider most essential to stock based on the Indian poisoning epidemiology you have studied — and why? How does that differ from the antidote priority in an urban hospital setting where drug overdose predominates? This kind of context-sensitive reasoning — not just memorisation — is what the NMC KH competency level demands.