CHT Cheat Sheet 2026

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

1. What is the generally accepted maximum oxygen partial pressure (PO2) to minimize risk of CNS oxygen toxicity during routine HBO treatments? → 1.6 ATA (1,216 mmHg)
2. Charles's Law describes the relationship between gas volume and: → Temperature at constant pressure
3. What documentation is required when equipment is replaced or upgraded? → Asset tracking records, disposal documentation, and updated operating procedures
4. What is the typical treatment pressure (ATA) used for most wound-healing and adjunctive HBO indications? → 2.0–2.4 ATA
5. Which vital sign parameter is MOST critical to assess before a patient enters a hyperbaric chamber for wound care treatment? → Blood glucose level
6. When should a practitioner modify their assessment approach? → When the patient presents with contraindications or special needs
7. Under NFPA 99, who is responsible for approving items brought into a Class A (monoplace oxygen) hyperbaric chamber? → The hyperbaric medical director or designee
8. Which condition would require IMMEDIATE emergency decompression of a hyperbaric chamber? → Uncontrolled fire inside the chamber that cannot be extinguished
9. Which federal agency enforces the Safe Medical Devices Act as it applies to hyperbaric chambers? → FDA
10. A hyperbaric facility loses main electrical power during a treatment at 45 fsw. What is the immediate priority? → Activate backup/emergency power and verify life support systems are operational
11. Why is communication equipment essential in multi-place chambers? → To allow communication between staff and patients
12. What is the primary purpose of maintaining accurate professional documentation? → To create a legal record of services and support continuity of care
13. How often should infection control training be updated? → Annually or per facility requirement
14. The 'chain of custody' concept in hyperbaric documentation primarily refers to: → Tracking who has accessed and modified a medical record
15. A patient completes a Table 6 treatment for DCS but neurological symptoms fully resolve only at depth. Per UHMS protocol, the most appropriate next step is: → Extend Table 6 at 60 fsw with additional oxygen periods
16. A patient scheduled for HBO therapy has a serum carboxyhemoglobin (COHb) level of 35%. This finding is MOST consistent with: → Acute carbon monoxide poisoning
17. At 3 ATA breathing 100% O2, approximately how much oxygen is dissolved in plasma? → 6.6 mL O2/100 mL blood
18. Which condition requires a hyperbaric chamber to be taken out of service until inspected by a qualified engineer or inspector? → Discovery of a crack, weld defect, or visible deformation in the pressure hull
19. What is the primary hazard of using petroleum-based lubricants on hyperbaric chamber fittings used with oxygen systems? → They can ignite spontaneously in an oxygen-enriched environment
20. Which of the following best describes the mechanism by which HBO reduces intracranial pressure in carbon monoxide poisoning? → HBO-induced vasoconstriction reduces cerebral edema
21. What is the primary function of hyperbaric oxygen therapy (HBOT)? → Enhance tissue oxygenation and healing
22. In the U.S. Navy Table 6 protocol, oxygen is breathed at 60 fsw (2.8 ATA) in cycles. What is the oxygen breathing schedule at 60 fsw? → Three 20-minute periods with two 5-minute air breaks
23. Which of the following is the hallmark presentation of CNS oxygen toxicity during HBO therapy? → Grand mal (tonic-clonic) convulsions
24. Which tool is used to monitor oxygen saturation in HBOT patients? → Pulse oximeter
25. According to NFPA 99, electrical equipment used inside a Class A hyperbaric chamber must be rated for use in: → Oxygen-enriched atmospheres
26. One atmosphere absolute (1 ATA) is equivalent to approximately: → 14.7 psi
27. A hyperbaric technician must replace a section of high-pressure oxygen tubing. Which tubing material is generally acceptable for this application? → Stainless steel or copper tubing rated and cleaned for oxygen service
28. During hyperbaric oxygen therapy, oxygen delivery to tissues is enhanced because dissolved plasma oxygen bypasses which normal physiological limiting factor? → Hemoglobin oxygen-carrying capacity
29. Which organization publishes the Hyperbaric Oxygen Therapy Indications document that CMS uses as a reference for reimbursement decisions? → Undersea and Hyperbaric Medical Society
30. What is the primary objective of hyperbaric chamber emergency procedures in Certified Hyperbaric Technician practice? → Ensuring consistent quality and adherence to professional standards