سموم

1. Toxicology
WHO Health Emergencies program (WHE)

2. WHO Health Emergencies program (WHE)
At the end of this lecture, you will be able to:
• Summarize the principles of poisoning management.
Learning objectives

3. WHO Health Emergencies program (WHE)
Questions
• Which overdose/poisoning patients need intubation?
• What are key clinical findings which aid in determining the type of poisoning/overdose?
• What ways can we possibly remove poisons/overdose from patients?
• Which patients should get activated charcoal?
• What poisons/overdoses do we have specific antidotes for?

4. WHO Health Emergencies program (WHE)
Drug Overdoses – Obtaining Hx
• Substance, amount and time.
• Reliable information often not available.
• Consider specific antidote-available OD.
• APAP, TCA, EG (toxic alcohols).
• APAP levels should be checked in all patients.
• Anion gap should be calculated in all unknown cases.

5. WHO Health Emergencies program (WHE)
• BP, RR, HR, Temp, Agitation:
• Sympathomimetics (cocaine, amphetamines).
• Anticholinergics (diphenhydramine).
• BP, RR, HR, Temp, Obtundation:
• Sedatives/hypnotics (benzos, barbs).
• Opiates (morphine, fentanyl).
• Antihypertensives/cardiac (blockers, digoxin).
Vital Sign Clues

6. WHO Health Emergencies program (WHE)
Specific Management
Drug antidote
Acetaminophen: N-acetylcysteine
Ethylene glycol: Fomepizole
Benzodiazepines: Flumazenil*
B-blockers: Glucagon
Ca channel blockers: Calcium
Carbon monoxide: 100% O2 , Hyperbaric O2
Cyclic antidepressants: Bicarbonate
Organophosphates: Atropine, Pralidoxime

7. WHO Health Emergencies program (WHE)
Clinical Characteristics That Aid in Diagnosis of
Poisoning/Overdose
Clinical Examination Possible Agents
Agitation, confusion,
bizarre behaviour
Cocaine, amphetamines, antidepressants, phencyclidine,
hallucinogens, SSRIs.
Bradycardia/hypotension
β-Blockers, barbiturates, calcium-channel blockers, clonidine,
digoxin, sedatives/hypnotics.
Coma, lethargy
Alcohols, antidepressants, barbiturates, benzodiazepines,
gamma-hydroxybutyrate, lithium, opiates, salicylates, SSRIs.
Hyperadrenergic, hyperthermia Amphetamines, anticholinergics, cocaine, theophylline.
Hypotension
Antidepressants, anticholinergics, opiates,
organophosphates/carbamates, sedatives, hypnotics.
Hypothermia Ethanol, hypoglycemic agents, opiates, sedatives/hypnotics.

8. WHO Health Emergencies program (WHE)
Clinical Characteristics That Aid in diagnosis of
Poisoning/Overdose
Clinical Examination Possible Agent
Miosis Cholinergic drugs, opiates, organophosphates, phencyclidine
Mydriasis
Antihistamines, atropine, tricyclic antidepressants, ethanol, sympathomimetic
drugs
Nausea/vomiting Acetaminophen, alcohols, iron, salicylates, theophylline
Nystagmus Alcohols, carbamazepine, phenytoin, phencyclidine, sedative/hypnotics
Seizures
Amphetamines, antidepressants, cocaine, cyanide, isoniazid,
lithium, organophosphates/carbamates, salicylates, SSRIs, theophylline
Tachyarrhythmias Amphetamines, antidepressants, caffeine, cocaine, digoxin, theophylline
Ventilatory compromise
(respiratory acidosis)
Opiates, alcohols, antidepressants, barbiturates,
benzodiazepines, gamma-hydroxybutyrate

9. WHO Health Emergencies program (WHE)
Clinical Characteristics That Aid in Diagnosis of
Poisoning/Overdose
Laboratory Tests Possible Agents
Increased osmolar gap
Ethanol, methanol, ethylene glycol, acetone, isopropyl alcohol,
propylene glycol.
Increased oxygen saturation gap Methemoglobinemia, carbon monoxide.
Metabolic acidosis
Acetaminophen, salicylates, methanol/ethylene glycol, iron
isoniazid, carbon monoxide, cyanide, propylene glycol, propofol.

10. WHO Health Emergencies program (WHE)
Anion Gap Metabolic Acidosis
• Na – (HCO3 + Cl)
• Normal <12
• DDx:
• Methanol
• Uremia
• DKA
• Paracetamol
• Isoniazid
• Lactic acid
• Ethylene glycol
• Salicylates

11. WHO Health Emergencies program (WHE)
General Management
• Airway & Breathing support.
• Circulation support.
• Consider cocktail in altered mental Status : Dextrose, Naloxone, Thiamine.
• Consider others: Charcoal.
• Specific management.

12. WHO Health Emergencies program (WHE)
Gastric Decontamination limited role
• Ipecac-induced emesis.
• Gastric lavage.
• Cathartics.
• Whole bowel irrigation
• Activated charcoal:
• Best if administered w/i 1-2 hrs. of ingestion of drug.
• Multiple dose in specific (Theophylline).

13. WHO Health Emergencies program (WHE)
Elimination of Toxins
• Multiple doses of charcoal
• Barbiturates, Theophylline, Carbamazepine, Dapsone, Quinine.
• Forced diuresis.
• Alkaline diuresis (urine pH>7).
• Barbiturates, Salicylates.
• Hemoperfusion (charcoal).
• e.g., Lithium.

14. WHO Health Emergencies program (WHE)
Summary
• In the treatment of patients with known or suspected poisoning/overdose, maintaining airway patency
and circulatory stabilization are the initial priorities.

15. WHO Health Emergencies program (WHE)
Refernces:
• Society of Critical Care Medicine Fundamental Critical Care Support course (FCCS 7th Edition)
https://www.sccm.org/Fundamentals/Fundamental-Critical-Care-support
• 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease:
• A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical
Practice Guidelines
• https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000000923