⚠️ Chapter 120: Poisoning (General Principles)

Toxidromes · Airway/breathing/circulation · Decontamination (activated charcoal, gastric lavage) · Enhanced elimination (urinary alkalinisation, dialysis) · Antidotes · N-acetylcysteine · Naloxone · Sodium bicarbonate · Atropine · Pralidoxime

🔍 Core Concepts: Poisoning — General Management

📌 Initial Assessment (ABCs)
Airway, breathing, circulation. Look for toxidromes (sympathomimetic, anticholinergic, cholinergic). Obtain ECG, glucose, electrolytes, ABG. Admission to ICU if altered sensorium, haemodynamic instability, seizures, or respiratory failure.
🧪 Decontamination
Activated charcoal 1 g/kg within 1-2h (not for alcohols, caustics, iron, lithium). Gastric lavage only for life-threatening ingestion within 1h. Whole bowel irrigation for sustained-release or body packers.
💊 Enhanced Elimination
Urinary alkalinisation (salicylates, phenobarbitone). Haemodialysis (methanol, ethylene glycol, lithium, salicylates). Haemoperfusion (theophylline, carbamazepine, barbiturates).
💉 Antidotes (Common)
Naloxone (opioids), N-acetylcysteine (paracetamol), sodium bicarbonate (TCA, wide QRS), atropine + pralidoxime (organophosphates), flumazenil (benzodiazepines — avoid in chronic use), digoxin-Fab, glucagon (beta-blockers/CCB).
⚠️ Toxic Alcohols
Methanol, ethylene glycol: high anion gap acidosis, osmolar gap. Fomepizole or ethanol (to block metabolism). Haemodialysis for severe toxicity.
🔥 Hyperthermia in poisoning
Sympathomimetics, anticholinergics, salicylates, serotonin syndrome. Treat with cooling, benzodiazepines, dantrolene if severe. Antipyretics ineffective.

🩺 Stepwise Approach: Suspected Poisoning

1
Initial resuscitation (ABCs)
Airway: intubate if GCS ≤8, airway compromise. Breathing: 100% O2, support ventilation. Circulation: IV access, fluid bolus 20 mL/kg if hypotensive, vasopressors if refractory.
2
Identify toxidrome & order labs
Pupils, heart rate, BP, skin, bowel sounds. ECG (QT, QRS). Bedside glucose. Labs: electrolytes, ABG, lactate, renal/hepatic function, paracetamol/salicylate levels, urine toxicology.
3
Decontamination (if indicated)
Activated charcoal 1 g/kg (within 1-2h, airway protected). Gastric lavage only for life-threatening ingestion <1h. Do NOT induce emesis. Whole bowel irrigation for sustained-release/body packs.
4
Specific antidotes & enhanced elimination
Wide QRS (TCA): sodium bicarbonate 1-2 mEq/kg. Opioids: naloxone 0.1 mg/kg. Paracetamol: N-acetylcysteine. Organophosphates: atropine + pralidoxime. Methanol/ethylene glycol: fomepizole, haemodialysis.
5
Supportive care & monitoring
Continuous ECG, pulse oximetry. Treat seizures with benzodiazepines. Hyperthermia: cooling, benzodiazepines. Monitor electrolytes, glucose, renal function. Re-evaluate for delayed toxicity.
6
Disposition
Admit to ICU if: altered sensorium, haemodynamic instability, seizures, respiratory failure, arrhythmias, or need for dialysis/antidote infusion. Observe asymptomatic patients for 4-6h.