Toxicology and Substance Abuse Flashcards
7 cards from real AEMCA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Toxicology and Substance Abuse flashcards as text
A patient is found unconscious in a closed garage with a running engine. What pulse oximetry reading would you most likely expect?
Answer: SpO2 of 98–100% (falsely normal)
Standard pulse oximetry cannot distinguish carboxyhemoglobin from oxyhemoglobin, giving a falsely normal or near-normal SpO2 reading in carbon monoxide poisoning.
Which class of substances accounts for the greatest number of drug overdose deaths in the United States?
Answer: Opioids (including synthetic opioids)
Opioids, particularly synthetic opioids such as illicitly manufactured fentanyl, account for the majority of drug overdose deaths in the US annually.
A patient presents with confusion, ataxia, and nystagmus after ingesting from an unlabeled bottle, but has no severe acidosis. Which toxic alcohol is most likely?
Answer: Isopropanol (rubbing alcohol)
Isopropanol causes CNS depression similar to ethanol (with ataxia and nystagmus) but is metabolized to acetone rather than an organic acid, so severe anion gap acidosis is absent.
What is the mechanism of action of physostigmine when used to treat anticholinergic toxicity?
Answer: Inhibits acetylcholinesterase, increasing synaptic acetylcholine levels
Physostigmine inhibits acetylcholinesterase, preventing breakdown of acetylcholine and thereby increasing its concentration to overcome the anticholinergic blockade at muscarinic receptors.
When a patient has ingested a caustic substance (strong acid or base), which prehospital intervention is contraindicated?
Answer: Inducing vomiting or gastric lavage
Inducing vomiting after caustic ingestion is contraindicated because it re-exposes the esophagus, oropharynx, and airway to the caustic substance, worsening mucosal injury.
A patient presents with confusion, visual disturbances, and severe metabolic acidosis after ingesting 'antifreeze.' Which toxic agent is most likely responsible?
Answer: Methanol
Methanol is metabolized to formic acid, which directly damages the optic nerve causing visual changes and blindness, along with severe high anion gap metabolic acidosis.
Which of the following statements about illicit fentanyl is TRUE and relevant to prehospital provider safety?
Answer: Fentanyl can be absorbed transdermally and through mucous membranes, posing exposure risk
Fentanyl is highly lipophilic and can be absorbed transdermally and through mucous membranes; illicitly manufactured fentanyl poses occupational exposure risks for EMS providers at overdose scenes.