Toxicology and Environmental Emergencies
Core concepts
Know the classic toxidromes (anticholinergic, cholinergic, sympathomimetic, opioid, sedative-hypnotic) and their antidotes. Understand decontamination principles and when activated charcoal is appropriate. Recognize the toxidrome-specific treatments: naloxone for opioids, flumazenil for benzodiazepines (with caution), sodium bicarbonate for tricyclic overdose, and N-acetylcysteine for acetaminophen.
For environmental emergencies, understand heat illness (heat exhaustion vs heat stroke), hypothermia, and the management of drowning and electrical injury. Know carbon monoxide and cyanide toxicity, including the role of hyperbaric oxygen and hydroxocobalamin. Understand venomous bites and stings and the indications for antivenom.
Traps
Questions test whether you can recognize a mixed overdose and whether you know that flumazenil can precipitate seizures in benzodiazepine-tolerant patients. Another trap: missing acetaminophen as a co-ingestant and failing to check a timed level. Watch for the "serotonin syndrome" versus "neuroleptic malignant syndrome" distinction.
Worked example / rule of thumb
A patient with salivation, lacrimation, urination, diarrhea, and bradycardia: think cholinergic poisoning and give atropine plus pralidoxime. Rule of thumb: "Treat the toxidrome, not the toxin - and always check acetaminophen and glucose in every overdose."