CHS Cheat Sheet 2026

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

1. What is a common protocol for hyperbaric therapy treatment duration? → 60 to 120 minutes
2. What is the primary reason hyperbaric oxygen is effective in carbon monoxide poisoning beyond simply displacing CO from hemoglobin? → It accelerates CO dissociation from intracellular myoglobin and cytochrome oxidase
3. What is evidence-based practice in CHS Pharmacology & Medication Management? → Integrating research evidence with expertise and client needs
4. Which physiological mechanism primarily accounts for the anti-ischemic benefit of hyperbaric oxygen in crush injuries? → Reduction of compartment syndrome edema via vasoconstriction
5. What is evidence-based practice in CHS Patient Assessment & Evaluation? → Integrating research evidence with expertise and client needs
6. What is the critical path in CHS project scheduling? → The longest sequence of dependent tasks determining minimum duration
7. What is peer review in CHS Infection Control & Prevention? → Quality evaluation by qualified colleagues for improvement
8. What does residual risk mean in CHS practice? → Risk remaining after all controls are implemented
9. Which physiological condition is a known predisposing factor that significantly increases the risk of CNS oxygen toxicity? → Hypercapnia (elevated CO2)
10. What is a risk matrix used for in CHS practice? → Evaluating risks by plotting likelihood against impact severity
11. A diving casualty presents with mottled skin rash, joint pain, and fatigue after a multi-day liveaboard trip. These symptoms are most consistent with: → Decompression sickness Type I (cutaneous and musculoskeletal)
12. The documentation required by CMS for hyperbaric oxygen therapy includes all of the following EXCEPT: → A signed waiver from the patient releasing the facility from liability for oxygen toxicity
13. How is patient progress typically monitored during hyperbaric therapy? → By observing symptoms and progress
14. What are the five process groups in CHS project management? → Initiating, Planning, Executing, Monitoring & Controlling, Closing
15. Why is hyperbaric oxygen therapy used in treating diabetic foot ulcers? → To improve tissue oxygenation and wound healing
16. What is the primary principle of hyperbaric medicine? → High-pressure oxygen therapy to enhance tissue oxygenation
17. The ASME PVHO-1 standard governs the design and construction of pressure vessels intended for: → Human occupancy under pressure
18. A chamber operator notices the pressure relief valve activating repeatedly during treatment. The FIRST action should be to: → Identify and resolve the source of overpressure before continuing
19. The Unit Pulmonary Toxicity Dose (UPTD) is used in HBO therapy to track: → Cumulative pulmonary oxygen exposure to prevent pulmonary toxicity
20. Which wound characteristic most strongly supports the use of HBOT as an adjunct for a diabetic lower extremity ulcer? → Wound with periwound TcPO2 below 40 mmHg that rises above 200 mmHg on HBO challenge
21. When assessing a wound for HBOT candidacy using TCOM, a reading that increases to above 200 mmHg in 100% O2 at 1 ATA indicates what? → Adequate vascular supply exists and HBOT is likely to be beneficial
22. During a hyperbaric treatment, the oxygen partial pressure (PO2) inside a multiplace chamber should not exceed which value to minimize oxygen toxicity risk? → 1.6 ATA
23. What is the role of fire safety procedures in hyperbaric therapy? → To prevent fire hazards in high-oxygen environments
24. What are record retention policies in CHS practice? → Rules defining how long records must be kept and when destroyed
25. A patient's chart reveals a history of spontaneous pneumothorax. This condition is considered: → An absolute contraindication to hyperbaric oxygen therapy
26. What is a risk matrix used for in CHS practice? → Evaluating risks by plotting likelihood against impact severity
27. What is the first step in CHS risk assessment? → Identifying potential hazards and threats
28. Which symptom represents the 'V' in the VENTIDC mnemonic for early CNS oxygen toxicity warning signs? → Visual changes such as tunnel vision
29. Which statement best describes the role of HBOT in treating compromised skin grafts and flaps? → HBOT reduces edema and supports angiogenesis to improve graft survival in at-risk tissue
30. Why is it important to ensure proper ventilation in a hyperbaric chamber? → To prevent fire hazards and maintain oxygen levels