Certified Hyperbaric Technologist Test Cheat Sheet 2026

The 30 highest-yield Certified Hyperbaric Technologist Test facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which condition is considered an absolute contraindication to hyperbaric oxygen therapy? → Untreated pneumothorax
2. What is the role of the hyperbaric technician during pressurization? → Monitors chamber pressure and patient safety
3. Which assessment best predicts whether a wound is likely to respond to HBO2 therapy? → Transcutaneous oximetry (TcPO2) measurements
4. The primary accreditation body for clinical hyperbaric medicine programs in the United States is: → Undersea and Hyperbaric Medical Society (UHMS)
5. Sinus squeeze (sinus barotrauma) is best prevented by: → Ensuring the patient is free of upper respiratory congestion before treatment
6. Which mechanism explains the reduction of gas embolism risk with HBOT? → Boyle’s Law compression of gas bubbles
7. In radiation-injured tissue, HBO promotes healing by: → Stimulating stem cell mobilization and angiogenesis in hypoxic tissue
8. Which gas law supports the need to monitor partial pressures of oxygen during therapy? → Dalton’s Law
9. Why must compression and decompression rates be controlled rather than rapid? → To allow pressure equalization and prevent barotrauma
10. Why are air breaks often incorporated into longer wound-treatment dives? → To reduce the risk of oxygen toxicity while maintaining therapy
11. Nitrogen narcosis is NOT a concern in HBO therapy primarily because: → Patients breathe 100% oxygen, eliminating nitrogen narcosis risk
12. What happens to gas volume when a patient ascends rapidly from depth? → Volume increases
13. Which statement about HBO and anticoagulants (e.g., warfarin) is correct? → HBO may enhance anticoagulant effects, requiring INR monitoring
14. Visual changes (myopia) experienced by patients after multiple HBO treatments are: → Usually reversible within weeks to months after completing therapy
15. What is the absolute pressure at 66 feet of seawater? → 3 ATA
16. Which symptom indicates possible pulmonary oxygen toxicity (Lorrain Smith effect) in a patient receiving multiple HBO sessions? → Substernal chest pain and cough between sessions
17. Which type of hyperbaric chamber allows multiple patients to be treated at once? → Multiplace chamber
18. What is 'flying DCS' (altitude DCS)? → DCS triggered by reduced atmospheric pressure during air travel after diving
19. Which of the following is an UHMS-approved indication for hyperbaric oxygen therapy? → Crush injury and acute traumatic ischemia
20. Which medication taken by a patient increases the risk of CNS oxygen toxicity during HBO? → Disulfiram (Antabuse)
21. What is the recommended action if a patient becomes claustrophobic during treatment? → Pause treatment and provide reassurance
22. A patient on doxorubicin (Adriamycin) chemotherapy requires HBO. What is the primary concern? → Increased pulmonary oxygen toxicity risk
23. Why are petroleum-based products strictly prohibited inside hyperbaric chambers? → They are highly flammable in oxygen-enriched environments
24. As ambient pressure increases, what happens to the density of breathing gas? → Density increases
25. When a patient is receiving HBO for a gas-forming infection, which antibiotic class works synergistically with HBO against Clostridium species? → Penicillins (e.g., ampicillin)
26. Which item is strictly prohibited inside a monoplace hyperbaric chamber due to fire risk? → Petroleum-based lip balm
27. Spinal cord DCS is most commonly seen in which segment of the spinal cord? → Thoracic and lumbar (lower extremity weakness, bladder dysfunction)
28. What temperature change occurs inside a chamber during decompression? → Temperature cools due to gas expansion
29. For a patient on the chemotherapy drug doxorubicin, the technologist should be aware that HBO2 may: → Potentiate the drug's cytotoxic and cardiotoxic effects
30. In treating decompression sickness, the U.S. Navy Treatment Table 6 is most commonly initiated at what pressure? → 2.8 ATA (60 fsw)