Poisoning

Rationale

Poisoning is common and potentially fatal. It can be accidental or intentional. Accidental poisoning is particularly common in children. In intentional poisoning, co-ingestion of substances occurs frequently.

Causal Conditions

(list not exhaustive)

1. Environmental
   1. Chemicals (e.g., carbon monoxide, detergents, pesticides)
   2. Plants (e.g., household plants, mushrooms)
   3. Animals (e.g., venomous bites)
2. Drug-related
   1. Central nervous system (CNS) depressants (e.g., alcohol, sedatives, hypnotics) and stimulants (e.g., amphetamines, cocaine)
   2. Anti-cholinergics (e.g., diphenhydramine, dimenhydrinate)
   3. Serotonergics (e.g., selective serotonin reuptake inhibitors)
   4. Cardiovascular drugs (e.g., digoxin, β-blockers, calcium channel blockers)
   5. Opioids (e.g., fentanyl, morphine)
   6. Nonopioid analgesics (e.g., acetylsalicylic acid, acetaminophen)

Key Objectives

Given a patient with poisoning, the candidate will diagnose the cause, severity, and complications, and initiate an appropriate management plan. The candidate will determine the nature of the toxicity and exposure and provide specific and supportive care based on the identified cause.

Enabling Objectives

Given a patient with poisoning, the candidate will

1. list and interpret critical clinical findings, including those based on
   1. a collateral history focused on determining the substance involved and the potential severity of the poisoning, and
   2. a physical examination focused on determining the stability of the patient and the nature of the toxidrome (e.g., cholinergic crisis, serotonergic syndrome);
2. list critical investigations and interpret the results of the investigations, including
   1. laboratory tests to measure the amount of the substance ingested (e.g., acetaminophen level, acetylsalicylic acid level), and
   2. assessment of the toxic effects on the patient (e.g., arterial blood gases, anion and osmolar gaps);
3. construct an effective initial management plan, including
   1. providing supportive care while information is being gathered and investigations are initiated (e.g., ensuring airway adequacy, ensuring hemodynamic stability),
   2. initiating appropriate decontamination and/or preventing further absorption (e.g., administering activated charcoal),
   3. administering specific antidotes if indicated (e.g., naloxone, N-acetylcysteine),
   4. eliminating the poison (e.g., alkalinization, dialysis),
   5. contacting a Poison Centre, and
   6. referring for psychiatric assessment if indicated.