CHT Hyperbaric Chamber Operations & Safety 2 — Questions and Answers
Question 1: During a hyperbaric treatment, a patient reports ear pain that does not resolve with swallowing or yawning. What is the correct action?
- Increase compression rate to push through the discomfort
- Stop compression immediately and begin slow decompression to the last comfortable depth (Correct answer)
- Continue compression and administer 100% oxygen
- Ask the patient to hold their nose and blow forcefully
Correct answer: Stop compression immediately and begin slow decompression to the last comfortable depth
If a patient cannot equalize and ear pain persists, compression must stop and the chamber should return to the last comfortable depth to prevent barotrauma.
Question 2: What is the minimum fire suppression requirement inside a multiplace hyperbaric chamber during operations?
- A CO2 extinguisher mounted outside the chamber
- An internal deluge or sprinkler system capable of rapid chamber flooding (Correct answer)
- A halon system activated from the inside only
- A dry chemical extinguisher accessible to the inside attendant
Correct answer: An internal deluge or sprinkler system capable of rapid chamber flooding
NFPA 99 and PVHO standards require multiplace chambers to have an internal deluge/sprinkler system to rapidly suppress fire in the oxygen-enriched environment.
Question 3: A monoplace chamber is pressurized with 100% oxygen to 2.0 ATA. What is the approximate partial pressure of oxygen the patient is breathing?
- 0.21 ATA
- 1.0 ATA
- 2.0 ATA (Correct answer)
- 2.4 ATA
Correct answer: 2.0 ATA
In a monoplace chamber pressurized with 100% oxygen, the partial pressure of O2 equals the absolute pressure — at 2.0 ATA, pO2 = 2.0 ATA.
Question 4: Which document governs hyperbaric facility safety standards in the United States?
- OSHA 29 CFR 1910.146
- NFPA 99 Health Care Facilities Code (Correct answer)
- ASME BPVC Section VIII
- FDA 21 CFR Part 820
Correct answer: NFPA 99 Health Care Facilities Code
NFPA 99 Health Care Facilities Code is the primary U.S. standard governing clinical hyperbaric facility safety, including chamber design, gases, and fire suppression.
Question 5: What is the purpose of performing a 'pressure test' on a hyperbaric chamber before a treatment session?
- To verify that the chamber can reach maximum operating pressure
- To confirm integrity of seals and absence of leaks before patient entry (Correct answer)
- To calibrate the oxygen analyzer
- To flush residual nitrogen from the previous dive
Correct answer: To confirm integrity of seals and absence of leaks before patient entry
A pre-session pressure test verifies that door seals, hull integrity, and penetration fittings are leak-free before a patient is placed inside.
Question 6: An inside attendant in a multiplace chamber notices a patient's mask has slipped off during treatment at 2.4 ATA. What should be done first?
- Immediately surface the chamber
- Assist the patient in repositioning the mask and verify seal (Correct answer)
- Switch the patient to chamber air breathing
- Record the event and continue without intervention
Correct answer: Assist the patient in repositioning the mask and verify seal
The first step is to assist the patient in correctly repositioning and sealing the mask so the therapeutic oxygen dose is not interrupted unnecessarily.
Question 7: During decompression, a patient in a multiplace chamber develops joint pain and mottled skin. Which condition does this most likely indicate?
- Oxygen toxicity seizure
- Arterial gas embolism
- Decompression sickness Type II (Correct answer)
- Nitrogen narcosis
Correct answer: Decompression sickness Type II
Joint pain combined with skin mottling (cutis marmorata) during or after decompression are classic signs of Type II (serious) decompression sickness.
CHT Hyperbaric Chamber Operations & Safety 2
During a hyperbaric treatment, a patient reports ear pain that does not resolve with swallowing or yawning.
What is the correct action?