CHS Emergency Procedures & Response 3 — Questions and Answers
Question 1: A patient in a monoplace chamber indicates ear pain at 20 fsw and cannot equalize. The correct procedure is to:
- Continue compression at a slower rate
- Stop compression and decompress to surface immediately
- Hold depth, coach equalization, and decompress if unsuccessful (Correct answer)
- Increase compression speed to pass through the pain quickly
Correct answer: Hold depth, coach equalization, and decompress if unsuccessful
The chamber should be held at current depth while equalization maneuvers are coached; if unsuccessful, decompression to surface is required to prevent tympanic membrane rupture.
Question 2: Which of the following items is considered an absolute contraindication to entering a hyperbaric chamber as a patient?
- Controlled hypertension
- Untreated tension pneumothorax (Correct answer)
- Mild claustrophobia
- Use of a nitroglycerin patch
Correct answer: Untreated tension pneumothorax
An untreated tension pneumothorax is an absolute contraindication because compression will worsen it and decompression will cause catastrophic expansion.
Question 3: During decompression, a multiplace chamber patient reports joint pain in the right knee. This presentation most likely indicates:
- Musculoskeletal strain from positioning
- Type I decompression sickness (Correct answer)
- Oxygen window effect
- Pulmonary barotrauma
Correct answer: Type I decompression sickness
Joint pain (the 'bends') appearing during or after decompression is the hallmark symptom of Type I decompression sickness, affecting musculoskeletal and lymphatic systems.
Question 4: The primary purpose of the oxygen air break during hyperbaric oxygen therapy is to:
- Allow the patient to rest from wearing the mask
- Reduce the risk of central nervous system oxygen toxicity (Correct answer)
- Decrease the total treatment pressure
- Prevent hypercapnia
Correct answer: Reduce the risk of central nervous system oxygen toxicity
Periodic air breaks interrupt continuous oxygen exposure and significantly reduce the cumulative risk of CNS oxygen toxicity seizures.
Question 5: In a hyperbaric emergency requiring CPR inside a multiplace chamber, rescuers must know that:
- Chest compressions are ineffective at elevated pressure
- Defibrillation is safe to use inside the chamber
- External defibrillation is contraindicated in oxygen-enriched environments (Correct answer)
- Ventilation volumes should be increased proportionally with depth
Correct answer: External defibrillation is contraindicated in oxygen-enriched environments
Defibrillation in an oxygen-enriched hyperbaric environment poses an extreme fire and explosion hazard and must not be performed inside the chamber.
Question 6: A hyperbaric technician notices smoke inside an occupied monoplace chamber. After activating the fire alarm, the NEXT step is:
- Maintain depth until the source is identified
- Begin emergency decompression immediately (Correct answer)
- Flood the chamber with nitrogen
- Increase chamber pressure to suppress combustion
Correct answer: Begin emergency decompression immediately
Smoke inside an occupied chamber is an immediate life threat; emergency decompression must begin at once to evacuate the patient.
Question 7: A patient treated for carbon monoxide poisoning in a hyperbaric chamber develops neurological symptoms 3 days after discharge. This phenomenon is called:
- Delayed neurological syndrome (Correct answer)
- Rebound hypoxia
- Post-treatment oxygen deficit
- Chronic CO toxicity
Correct answer: Delayed neurological syndrome
Delayed neurological syndrome (DNS) is a well-recognized complication of CO poisoning that can appear days to weeks after apparent recovery, even after successful HBO treatment.
CHS Emergency Procedures & Response 3
A patient in a monoplace chamber indicates ear pain at 20 fsw and cannot equalize.
The correct procedure is to: