CPEN Environmental Emergencies 3 — Questions and Answers
Question 1: A 5-year-old is stung by a scorpion in Arizona. The child is drooling, has roving eye movements, and is agitated with abnormal limb movements. Which medication is MOST effective for severe scorpion envenomation in the US?
- Diphenhydramine IV
- Antivenom (Anascorp) (Correct answer)
- Midazolam for symptom control only
- Calcium gluconate IV
Correct answer: Antivenom (Anascorp)
Centruroides scorpion antivenom (Anascorp) rapidly reverses neurotoxic symptoms including cranial nerve dysfunction, excessive secretions, and motor abnormalities.
Question 2: An 8-year-old develops a wound with a bulls-eye rash 5 days after a camping trip in the Northeastern US. She reports fatigue and arthralgia. The nurse suspects Lyme disease. Which treatment should be anticipated?
- Amoxicillin for 14–21 days (Correct answer)
- Doxycycline for 14–21 days
- Azithromycin for 5 days
- Ceftriaxone IV for 28 days
Correct answer: Amoxicillin for 14–21 days
Amoxicillin is the preferred antibiotic for early Lyme disease in children under 8; doxycycline is reserved for children ≥8 years due to dental staining risk.
Question 3: A 2-year-old is found in a garage with suspected CO exposure. The child is crying and has a carboxyhemoglobin (COHb) level of 22%. SpO₂ by pulse oximetry reads 98%. Which statement BEST explains this discrepancy?
- The oximeter malfunctioned in the cold environment
- Pulse oximetry cannot distinguish COHb from oxyhemoglobin (Correct answer)
- The child has compensatory polycythemia from chronic exposure
- Tissue oxygen delivery is normal at this COHb level
Correct answer: Pulse oximetry cannot distinguish COHb from oxyhemoglobin
Standard pulse oximeters cannot differentiate carboxyhemoglobin from oxyhemoglobin, giving falsely normal SpO₂ readings; co-oximetry blood gas is required.
Question 4: A 12-year-old rock climber falls into a fast-moving river and is submerged for 6 minutes in 8°C water before rescue. He has a core temp of 28°C and is pulseless. What is the MOST appropriate resuscitation approach?
- Declare death and do not attempt resuscitation due to prolonged submersion
- Begin CPR and transport for ECMO-supported rewarming (Correct answer)
- Perform defibrillation immediately before any other intervention
- Rewarm passively to 32°C before initiating CPR
Correct answer: Begin CPR and transport for ECMO-supported rewarming
Cold water submersion victims with hypothermic cardiac arrest should receive CPR and be transported for extracorporeal rewarming (ECMO), as hypothermia is protective and full recovery is possible.
Question 5: A 9-year-old develops a painful, blistered wound on the foot after stepping on a stingray. Which treatment is MOST effective for pain control?
- Apply ice packs to the wound for 20 minutes
- Immerse the foot in hot water (43–45°C) for 30–90 minutes (Correct answer)
- Elevate and wrap with a compression bandage
- Apply topical hydrocortisone cream immediately
Correct answer: Immerse the foot in hot water (43–45°C) for 30–90 minutes
Hot water immersion (as hot as tolerated, 43–45°C) denatures the heat-labile proteins in stingray venom, providing rapid pain relief.
Question 6: During a wilderness camping trip, a 14-year-old develops sudden headache, ataxia, and vomiting at an altitude of 3,500 meters. Examination reveals papilledema. Which condition does this presentation indicate?
- Acute Mountain Sickness (AMS)
- High-Altitude Cerebral Edema (HACE) (Correct answer)
- High-Altitude Pulmonary Edema (HAPE)
- Decompression sickness
Correct answer: High-Altitude Cerebral Edema (HACE)
Papilledema, ataxia, and altered neurological status at high altitude indicate High-Altitude Cerebral Edema, a life-threatening progression of AMS.
Question 7: A 7-year-old is bitten by a cottonmouth snake on the hand. The hand is edematous with two fang marks and painful ecchymosis spreading to the forearm. Which lab abnormality is MOST expected with pit viper envenomation?
- Thrombocytosis and elevated fibrinogen
- Prolonged PT/INR, low fibrinogen, and thrombocytopenia (Correct answer)
- Leukopenia and elevated aPTT only
- Hypocalcemia and metabolic alkalosis
Correct answer: Prolonged PT/INR, low fibrinogen, and thrombocytopenia
Pit viper venom causes venom-induced consumptive coagulopathy with prolonged PT/INR, decreased fibrinogen, and thrombocytopenia from fibrinogen consumption.
CPEN Environmental Emergencies 3
A 5-year-old is stung by a scorpion in Arizona.
The child is drooling, has roving eye movements, and is agitated with abnormal limb movements.
Which medication is MOST effective for severe scorpion envenomation in the US?