Overview
This lecture covers the basics of toxicology, focusing on poison classifications, routes of exposure, assessment, treatment, and specific types of poisoning emergencies that EMTs may encounter.
Introduction to Toxicology
- Toxicology is the study of poisonous substances and their effects on the body.
- A poison is a substance that can damage body structures or impair function.
- A toxin is a poison produced naturally by organisms like bacteria, animals, or plants.
- Substance abuse refers to the misuse of substances to produce a desired effect; overdose is a common complication.
Routes of Poison Exposure
- Four main routes: inhalation (breathing in), absorption (skin contact), ingestion (eating/drinking), and injection (puncture/IV).
- All routes can lead to life-threatening emergencies.
- Treatment and assessment depend on the exposure route.
Assessment & General Management
- Scene safety and standard precautions are essential to avoid personal exposure.
- During assessment, try to identify the substance, amount, time, and method of exposure.
- Monitor airway, breathing, and circulation (ABCs) and provide oxygen if needed.
- Collect evidence (e.g., containers, vomit) for hospital staff.
- Notify poison control/medical control for treatment guidance.
- Activated charcoal may be used for some ingested poisons (1 g/kg body weight).
Poison Classifications & Specific Agents
- Alcohol: CNS depressant; withdrawal can be life-threatening (delirium tremens).
- Opiates/Opioids: CNS depressants; cause respiratory depression and pinpoint pupils; treat with naloxone (Narcan).
- Sedative-hypnotics (barbiturates/benzodiazepines): CNS depressants; monitor and transport.
- Inhalants: CNS effects range from drowsiness to coma; risk of sudden death.
- Sympathomimetics (stimulants like cocaine, amphetamines): Cause agitation, tachycardia, and seizures.
- Bath salts: Synthetic stimulants, can cause prolonged agitation and hallucinations.
- Marijuana: Causes euphoria, relaxation, and sometimes hyperemesis syndrome.
- Hallucinogens (LSD): Cause altered perceptions, hallucinations, anxiety, and paranoia.
- Anticholinergics: Block parasympathetic nerves; classic symptoms are "hot, blind, dry, red, mad."
- Cholinergics (organophosphates/nerve agents): Cause "SLUDGE" or "DUMBELS" symptoms (excessive secretions, muscle twitching, seizures).
Food and Plant Poisonings
- Food poisoning: Usually bacterial toxins (e.g., salmonella, staph) cause GI symptoms, sometimes botulism.
- Plant poisonings: Many household plants are toxic; effects vary from local irritation to systemic symptoms.
Key Terms & Definitions
- Toxicology — study of poisons and their effects.
- Poison — any substance causing harm to body functions.
- Toxin — poison produced by living organisms.
- Tolerance — need for increasing amounts of a substance for the same effect.
- Activated charcoal — substance that binds and prevents absorption of certain poisons.
- Naloxone (Narcan) — opioid overdose antidote.
Action Items / Next Steps
- Review local EMS protocols for poison management and administration of activated charcoal or naloxone.
- Read textbook Chapter 22, focusing on signs, symptoms, and treatments of different poisonings.
- Practice converting pounds to kilograms for medication dosing calculations.
- Study mnemonics like "SLUDGE" and "DUMBELS" for cholinergic poisoning.