CPEN Environmental Emergencies 4 — Questions and Answers
Question 1: A 10-year-old is found in a snowbank unconscious with a core temperature of 26°C. The child has a pulse of 28 bpm and BP 60/40. Which cardiac rhythm is MOST associated with severe hypothermia at this temperature?
- Ventricular fibrillation
- Atrial fibrillation with slow ventricular response
- Complete heart block
- Osborn (J) waves on sinus rhythm (Correct answer)
Correct answer: Osborn (J) waves on sinus rhythm
Osborn (J) waves are pathognomonic ECG findings in hypothermia, representing abnormal ventricular repolarization at low core temperatures.
Question 2: A 16-year-old is brought to the ED after a rave event with suspected MDMA (ecstasy) use. She is hyperthermic (39.9°C), diaphoretic, and has Na of 118 mEq/L with seizures. What is the mechanism of hyponatremia in this scenario?
- MDMA causes direct renal sodium wasting
- MDMA stimulates ADH release combined with excessive water intake (Correct answer)
- Hyperthermia causes osmotic shift of sodium into cells
- MDMA inhibits aldosterone, causing sodium loss
Correct answer: MDMA stimulates ADH release combined with excessive water intake
MDMA stimulates inappropriate ADH (SIADH) secretion and users often drink excessive water to prevent hyperthermia, causing dilutional hyponatremia.
Question 3: A 4-year-old is found unresponsive in an unventilated bathroom where a space heater has been running. Parents report the child 'just wouldn't wake up.' CO level is 35%. After 100% O₂ is initiated, when should hyperbaric oxygen (HBO) therapy be considered?
- All pediatric CO exposures regardless of symptoms
- COHb >15% with loss of consciousness or neurological symptoms (Correct answer)
- COHb >25% without symptoms
- Only when COHb remains >20% after 4 hours of NBO
Correct answer: COHb >15% with loss of consciousness or neurological symptoms
HBO is indicated for pediatric CO poisoning with loss of consciousness, severe neurological symptoms, or high COHb (>25%), with lower thresholds for young children due to higher sensitivity.
Question 4: A 6-year-old sustained a brown recluse spider bite 72 hours ago. The wound now has a central necrotic eschar with surrounding erythema and a violaceous halo. What complication should the emergency nurse monitor for systemically?
- Disseminated intravascular coagulation (DIC)
- Acute hemolytic anemia and renal failure (Correct answer)
- Septic shock from wound infection
- Anaphylaxis from ongoing venom absorption
Correct answer: Acute hemolytic anemia and renal failure
Systemic loxoscelism from brown recluse venom can cause massive intravascular hemolysis, hemoglobinuria, and acute renal failure in severe cases.
Question 5: An 11-year-old is brought in by parents after being found in a detached garage where a generator was running. The child is conscious but complains of headache and nausea. The father also has a headache. Which intervention should occur FIRST?
- Obtain IV access and draw COHb level
- Remove both from the source and apply 100% O₂ via NRB mask (Correct answer)
- Perform a 12-lead ECG to assess for dysrhythmia
- Administer activated charcoal to prevent further absorption
Correct answer: Remove both from the source and apply 100% O₂ via NRB mask
Removing the patient from the CO source and immediately applying 100% oxygen is the priority to terminate ongoing exposure and accelerate CO elimination.
Question 6: A 13-year-old presents with a tick embedded in the scalp for an estimated 36 hours after a camping trip in North Carolina. Vital signs show T 39.1°C, HR 118, and the child has petechiae on the wrists and ankles. Which diagnosis requires IMMEDIATE antibiotic treatment?
- Lyme disease with early dissemination
- Rocky Mountain Spotted Fever (RMSF) (Correct answer)
- Ehrlichiosis
- Tick paralysis
Correct answer: Rocky Mountain Spotted Fever (RMSF)
Rocky Mountain Spotted Fever presents with fever, rash (petechiae on extremities), and tick exposure, requiring immediate doxycycline regardless of age due to the high mortality of untreated disease.
Question 7: During a recreational diving accident, a 15-year-old surfaces rapidly from 18 meters and develops joint pain, skin mottling, and right-sided hemiparesis. Which treatment is DEFINITIVE for decompression sickness?
- 100% O₂ via NRB mask and IV normal saline
- Hyperbaric oxygen (HBO) recompression therapy (Correct answer)
- Emergent neurosurgical consultation for arterial gas embolism
- Aspirin and anticoagulation to prevent thrombosis
Correct answer: Hyperbaric oxygen (HBO) recompression therapy
Hyperbaric oxygen recompression therapy is the definitive treatment for decompression sickness, reducing bubble size and restoring oxygen delivery to ischemic tissues.
CPEN Environmental Emergencies 4
A 10-year-old is found in a snowbank unconscious with a core temperature of 26°C.
The child has a pulse of 28 bpm and BP 60/40.
Which cardiac rhythm is MOST associated with severe hypothermia at this temperature?