CFRN Environmental and Toxicological Emergencies 4 — Questions and Answers
Question 1: A patient with frostbite to both hands has been in a warm transport environment for 30 minutes. The thawed tissue now appears blistered and edematous. What is the most important management principle?
- Debride all blisters immediately
- Avoid refreezing the thawed tissue at all costs (Correct answer)
- Rewarm with direct dry heat such as a heat lamp
- Massage the affected tissue vigorously to restore circulation
Correct answer: Avoid refreezing the thawed tissue at all costs
Refreezing previously thawed tissue causes far greater cellular damage than the original frostbite, making prevention of refreezing the top priority.
Question 2: A patient develops muscle rigidity, hyperthermia, diaphoresis, and clonus after starting a new serotonergic medication. What is the most likely diagnosis?
- Neuroleptic malignant syndrome
- Serotonin syndrome (Correct answer)
- Malignant hyperthermia
- Anticholinergic toxidrome
Correct answer: Serotonin syndrome
Serotonin syndrome presents with the triad of mental status change, autonomic dysfunction, and neuromuscular abnormalities (especially clonus) after serotonergic drug exposure.
Question 3: During a mass casualty event involving nerve agent exposure, patients are being triaged. Which finding indicates the patient is in immediate life threat and requires antidotal therapy without delay?
- Mild miosis and rhinorrhea only
- Seizures, loss of consciousness, and severe bronchospasm (Correct answer)
- Nausea and abdominal cramping
- Localized sweating at the exposure site
Correct answer: Seizures, loss of consciousness, and severe bronchospasm
Severe nerve agent toxicity with seizures, unconsciousness, and bronchospasm indicates crisis-level acetylcholinesterase inhibition requiring immediate atropine and pralidoxime.
Question 4: A patient is being transported after a rattlesnake bite to the lower leg. The leg is markedly edematous and the patient's coagulation studies are severely deranged. What is the treatment priority in flight?
- Apply a tourniquet proximal to the bite to limit venom spread
- Initiate antivenom (CroFab) as early as possible and supportive care (Correct answer)
- Incise and suction the wound
- Immobilize and elevate the extremity above heart level
Correct answer: Initiate antivenom (CroFab) as early as possible and supportive care
CroFab antivenom is the definitive treatment for Crotalid (rattlesnake) envenomation and should be administered as soon as possible to halt venom-induced coagulopathy.
Question 5: A patient is found unconscious in a garage with an idling vehicle. En route, the patient has been on 100% oxygen for 15 minutes but remains confused. What intervention should be planned at the receiving facility?
- Continued normobaric 100% oxygen for 24 hours
- Hyperbaric oxygen therapy (Correct answer)
- Sodium thiosulfate administration
- Methylene blue infusion
Correct answer: Hyperbaric oxygen therapy
Hyperbaric oxygen therapy is indicated for severe CO poisoning (unconsciousness, neurological deficits) to accelerate CO elimination and reduce delayed neurological sequelae.
Question 6: A pediatric patient ingested an unknown quantity of calcium channel blockers. Despite fluid resuscitation and vasopressors, hypotension persists. Which adjunct therapy has shown benefit in refractory CCB toxicity?
- High-dose magnesium sulfate
- High-dose insulin euglycemic therapy (HIET) (Correct answer)
- Sodium bicarbonate bolus
- Activated charcoal via nasogastric tube
Correct answer: High-dose insulin euglycemic therapy (HIET)
High-dose insulin euglycemic therapy improves cardiac contractility in CCB toxicity by providing alternative energy substrate to myocardial cells impaired by calcium channel blockade.
Question 7: A patient develops heat stroke with core temperature of 41.5°C after a marathon. What is the most effective cooling method available in a flight environment?
- Antipyretics (acetaminophen or ibuprofen)
- Ice water immersion or aggressive evaporative cooling with ice packs to axillae and groin (Correct answer)
- Passive cooling with removal of clothing only
- Cool IV fluids at 4°C as the sole cooling measure
Correct answer: Ice water immersion or aggressive evaporative cooling with ice packs to axillae and groin
Aggressive evaporative cooling combined with ice packs to high-flow vascular regions is the fastest effective method available during air transport for exertional heat stroke.
CFRN Environmental and Toxicological Emergencies 4
A patient with frostbite to both hands has been in a warm transport environment for 30 minutes.
The thawed tissue now appears blistered and edematous.
What is the most important management principle?