Toxicology – Rapid Review Notes
Key Definitions
- Toxicology: study of poisonous substances
- Poison: any substance that harms body structures/functions
- Toxin: poison produced biologically (bacteria, plants, animals)
- Substance abuse: misuse for desired effect; overdose = toxic dose
- Tolerance: \uparrow dose needed for same effect; Addiction = overwhelming need
Common Statistics
- \approx 80\% of poisonings via ingestion
- Acute poisoning: >2 million cases/yr; pediatric cases decreasing, adult chronic deaths rising
Routes of Exposure & Core Care
- Inhalation: move to fresh air, high-flow O_2, hazmat if gas suspected
- Absorption/Surface: brush dry powder, flush 15{-}20 min, remove clothes; irrigate eyes from nose outward
- Ingestion: assess XABCs, consider activated charcoal (if protocol) 1\,g/kg; contraindications = caustics, hydrocarbons, ↓LOC
- Injection: monitor airway, high-flow O_2, remove jewelry, rapid transport; field dilution impossible
Scene & Assessment Priorities
- Scene safety, PPE, look for clues (odors, meds, paraphernalia)
- Primary: ensure airway/ventilation, anticipate vomiting (suction)
- History: WHAT, WHEN, HOW MUCH, prior interventions, weight
- Reassess vitals: stable every 15 min; unstable every 5 min or continuously
Key Antidotes / Interventions
- Naloxone: reverses opioid OD; IN/IM/IV; give for apnea/agonal breaths
- DuoDote (atropine + pralidoxime): organophosphate/nerve agent exposure
- Activated charcoal: premixed 50 g adult; pediatric example 55\,lb/2.2=25\,kg\rightarrow25\,g
Characteristic Toxidromes
- Opioids: CNS ↓, pinpoint pupils, bradypnea; risk of arrest
- Sedative-hypnotics: drowsy, calm, ventilatory support needed
- Sympathomimetics (cocaine, amphetamines, MDMA): agitation, \uparrow BP/HR, dilated pupils, seizure risk
- Anticholinergics (atropine, antihistamines, TCAs): "hot, blind, dry, red, mad"; rapid deterioration
- Cholinergics (organophosphates): DUMBELS/SLUDGEM; copious secretions, bradycardia; decontaminate first
- Inhalants (halogenated solvents): arrhythmia risk—avoid exertion
- Hydrogen sulfide: rotten-egg odor; pulmonary/CNS failure, hazmat clearance
- Alcohol: CNS depressant; watch for hypoglycemia, DTs (agitation, tremors, seizures)
- Synthetic cathinones (bath salts): prolonged psychosis, tachycardia; ALS for sedation
- Marijuana/THC: euphoria ⇒ anxiety/paranoia; watch for cannabinoid hyperemesis
Food & Plant Poisoning Essentials
- Bacterial causes (Salmonella, Staph, Botulism); neuro signs in botulism
- Bring suspected food/plant to ED; don’t identify in field
High-Yield Exam Nuggets
- Brush then flush dry chemicals (not immediate water)
- Collect vomitus with pill fragments for hospital analysis
- Least pertinent overdose question: “Why did you take it?”
- DUMBELS "E" = Emesis
- Most serious contact hazard: self-contamination—use PPE
