REMOVAL AND ELIMINATION OF INGESTED POISON

Removal and elimination of poison (decontamination) has to be implemented AFTER stabilization of vital signs.

Removal from the stomach

  • Balance the dangers of attempting to empty the stomach against the likely toxicity of any swallowed poison as determined by the type of poison and amount swallowed against the risk of inhalation
  • Do not induce vomiting
  • Gastric lavage
    • Only useful if done within 2 hours of poisoning (except with salicylates or anticholinergics when it may be of use within 4 to 6 hours)
    • Seldom practicable or necessary before the patient reaches hospital
    • Contraindications: drowsy or comatose patients and if poisoning with corrosive or petroleum products

Prevention of absorption and active elimination

  • Oral activated charcoal can bind many poisons in the stomach and reduce their absorption
  • It is more effective the sooner it is given but may still work up to 2 hours after poisoning (longer with modified-release products and anticholinergics)
  • Contraindications
    • Depressed mental status
    • Late presentation
    • Ingestion of corrosives and petroleum products
    • Toxins poorly absorbed by charcoal (e.g. metals like iron,
      lithium, alcohol)
    • Intestinal obstruction
  • It is generally safe and especially useful for poisons toxic in small amounts, e.g. antidepressants

TREATMENT

Prevention of absorption
  • Dose: activated charcoal powder 50 g
    Child: 0.5-1 g/kg

    • Grind tablets into a fine powder before mixing with 100-200 ml of water (50 g = 200 tablets of 250 mg)
    • If patient unable to swallow the charcoal/water mixture (slurry), give by gastric lavage tube
Active elimination
  • Repeated doses of activated charcoal may be beneficial in some cases, e.g., acetylsalicylic acid, carbamazepine, phenobarbital, phenytoin, quinine, theophylline
    • Give activated charcoal 50 g repeated every 4 hours
  • Treat any vomiting as this may reduce the ffectiveness of the charcoal
In case of intolerance
  • Reduce dose and increase frequency, e.g., 25 g every 2 hours, or 12.5 g every hour.