FISDAP Toxicology and Substance Abuse — Questions and Answers
Question 1: A patient is found unresponsive with pinpoint pupils, slow respirations (4/min), and cyanosis. Bystanders report heroin use. What is the priority intervention?
- Administer activated charcoal
- Establish IV access and administer dextrose
- Support ventilation and administer naloxone (Correct answer)
- Place the patient in the recovery position and monitor
Correct answer: Support ventilation and administer naloxone
The classic opioid toxidrome (unresponsive, pinpoint pupils, respiratory depression) is reversed by naloxone (Narcan), an opioid antagonist. However, ventilatory support must begin immediately — airway and breathing take priority, and naloxone is given concurrently or immediately after.
Question 2: A patient presents with salivation, lacrimation, urination, defecation, GI distress, and emesis (SLUDGE). The patient was spraying insecticide. What class of toxin is responsible?
- Opioids
- Organophosphates (cholinergic agents) (Correct answer)
- Sympathomimetics
- Benzodiazepines
Correct answer: Organophosphates (cholinergic agents)
SLUDGE is the mnemonic for cholinergic toxidrome caused by organophosphate or carbamate insecticides, which inhibit acetylcholinesterase. Treatment includes atropine (to block muscarinic effects) and pralidoxime (2-PAM) to reactivate cholinesterase.
Question 3: An EMT responds to a patient found in a closed garage with a running vehicle. The patient is confused and has a headache. Skin color appears flushed and cherry-red. What is the most appropriate initial treatment?
- Administer naloxone and transport
- Remove the patient from the environment and administer 100% high-flow oxygen (Correct answer)
- Provide rescue breathing only and monitor SpO2
- Administer aspirin and transport for cardiac evaluation
Correct answer: Remove the patient from the environment and administer 100% high-flow oxygen
These are classic signs of carbon monoxide (CO) poisoning. CO displaces oxygen from hemoglobin. The antidote is high-flow 100% oxygen, which accelerates CO elimination. Standard pulse oximetry is unreliable in CO poisoning — SpO2 will read falsely normal because CO-bound hemoglobin reads as oxyhemoglobin.
Question 4: A patient who takes tricyclic antidepressants (TCAs) is found unresponsive with a wide QRS complex on the monitor. Which treatment is most appropriate for this toxicity?
- Administer naloxone 2 mg IV
- Administer sodium bicarbonate to alkalinize the blood (Correct answer)
- Give activated charcoal and induce vomiting
- Perform immediate synchronized cardioversion
Correct answer: Administer sodium bicarbonate to alkalinize the blood
TCA overdose causes sodium channel blockade, leading to a wide QRS and dysrhythmias. Sodium bicarbonate alkalinizes the blood and raises sodium levels, partially reversing the channel blockade and narrowing the QRS. Naloxone is ineffective; vomiting is contraindicated with altered mental status.
Question 5: A patient presents with hyperthermia, tachycardia, hypertension, dilated pupils, and agitation after cocaine use. Which toxidrome does this represent?
- Cholinergic toxidrome
- Opioid toxidrome
- Sympathomimetic toxidrome (Correct answer)
- Sedative-hypnotic toxidrome
Correct answer: Sympathomimetic toxidrome
Cocaine and other stimulants produce a sympathomimetic toxidrome: the body is in a hyper-adrenergic state with increased heart rate, blood pressure, temperature, and agitation, along with mydriasis (dilated pupils). Management is supportive — benzodiazepines for agitation, cooling for hyperthermia.
Question 6: A patient with a history of chronic alcohol use is now having a seizure. He reports his last drink was 48 hours ago. What is the most likely cause?
- Acute alcohol intoxication causing CNS depression
- Alcohol withdrawal seizure (Correct answer)
- Wernicke's encephalopathy from thiamine deficiency
- Hypercalcemia from liver disease
Correct answer: Alcohol withdrawal seizure
Alcohol withdrawal seizures typically occur 24–72 hours after the last drink in dependent individuals. Chronic alcohol use downregulates GABA receptors; when alcohol is removed, CNS excitability rebounds, which can cause seizures or delirium tremens (DTs). This is life-threatening and requires hospital management.
FISDAP Toxicology and Substance Abuse
A patient is found unresponsive with pinpoint pupils, slow respirations (4/min), and cyanosis.
Bystanders report heroin use.
What is the priority intervention?