CHS Hyperbaric Equipment Operation & Safety 3 — Questions and Answers
Question 1: When performing a pre-treatment electrical safety check on a monoplace chamber, which item is most critical to verify?
- All electrical equipment inside the chamber is rated for oxygen-enriched environments (Correct answer)
- The chamber lighting produces at least 500 lux
- The intercom system uses standard consumer-grade wiring
- The power supply uses AC rather than DC current
Correct answer: All electrical equipment inside the chamber is rated for oxygen-enriched environments
Inside a monoplace chamber, the atmosphere can approach 100% oxygen, so all electrical devices must be rated for oxygen-enriched environments to prevent ignition.
Question 2: A patient exhibits muscle twitching and facial grimacing at 2.4 ATA during 100% oxygen breathing. The operator should FIRST:
- Switch the patient to air and begin emergency ascent protocol (Correct answer)
- Increase the treatment pressure to suppress the symptoms
- Administer oxygen at a higher flow rate
- Continue treatment and document the observation
Correct answer: Switch the patient to air and begin emergency ascent protocol
These are classic prodromal signs of CNS oxygen toxicity; the immediate response is to remove the oxygen source and decompress according to the emergency protocol.
Question 3: The CO2 scrubber in a multiplace hyperbaric chamber using soda lime must be changed based on which primary indicator?
- Color change of the soda lime indicator dye or CO2 monitor alarm threshold (Correct answer)
- A fixed 8-hour time schedule regardless of usage
- Patient complaint of headache only
- Visible moisture condensation on the canister
Correct answer: Color change of the soda lime indicator dye or CO2 monitor alarm threshold
Soda lime exhaustion is best detected by the color-change indicator dye or by CO2 monitoring, as time-based schedules alone may not account for varying patient loads.
Question 4: What is the maximum allowable oxygen percentage in the ambient atmosphere of a multiplace chamber per NFPA 99?
- 23.5% (Correct answer)
- 21%
- 25%
- 30%
Correct answer: 23.5%
NFPA 99 specifies that the ambient oxygen concentration in a multiplace chamber must not exceed 23.5% to minimize fire hazard.
Question 5: Which document must be completed before every hyperbaric treatment session to verify equipment readiness?
- Pre-treatment equipment checklist (Correct answer)
- Annual maintenance log
- Patient insurance verification form
- Decompression sickness incident report
Correct answer: Pre-treatment equipment checklist
A pre-treatment equipment checklist confirms that all chamber systems, safety devices, and emergency equipment are functional before each session.
Question 6: During pressurization, a patient signals ear pain at 1.3 ATA. The correct operator response is to:
- Stop compression immediately and ascend slightly to relieve pressure (Correct answer)
- Increase compression rate to pass through the painful range quickly
- Switch from air to 100% oxygen to relieve the pain
- Ignore the signal and complete pressurization to treatment depth
Correct answer: Stop compression immediately and ascend slightly to relieve pressure
Ear pain during descent indicates middle ear barotrauma; the standard response is to halt compression and decompress slightly to allow the patient to equalize.
Question 7: The ASME PVHO-1 standard governs the design and construction of pressure vessels intended for:
- Human occupancy under pressure (Correct answer)
- Industrial gas storage only
- Medical oxygen cylinders
- Submarine hull construction
Correct answer: Human occupancy under pressure
ASME PVHO-1 specifically applies to pressure vessels for human occupancy (PVHO), establishing design, materials, and testing requirements for hyperbaric chambers.
CHS Hyperbaric Equipment Operation & Safety 3
When performing a pre-treatment electrical safety check on a monoplace chamber, which item is most critical to verify?