Mixed Deck — All CHS Topics Flashcards
100 cards from real CHS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All CHS Topics flashcards as text
When inspecting a hyperbaric chamber viewport (acrylic window), which finding requires the chamber to be taken out of service immediately?
Answer: A crazing crack or deep scratch that penetrates the acrylic material
Crazing or deep scratches in acrylic viewports indicate structural compromise; such viewports can fail catastrophically under pressure and must be replaced before use.
Which formula correctly expresses absolute pressure (ATA) for a diver at depth D in feet of seawater?
Answer: ATA = 1 + (D / 33)
Absolute pressure in ATA equals 1 (surface atmospheric pressure) plus the gauge pressure, where each 33 feet of seawater adds 1 ATA.
In CHS practice, what constitutes a conflict of interest?
Answer: When personal interests could compromise professional judgment
A conflict of interest occurs when personal, financial, or other interests could potentially influence professional judgment and decisions.
In hyperbaric facilities, the primary reason for prohibiting wool and synthetic fabrics inside the chamber is:
Answer: These materials generate static electricity that can act as an ignition source in oxygen-enriched atmospheres
Synthetic and wool fabrics can generate electrostatic discharge, which is a significant ignition risk in hyperbaric oxygen environments.
A hyperbaric chamber operator discovers a patient is experiencing arterial gas embolism (AGE) immediately after surfacing from a dive. The treatment protocol of choice is:
Answer: US Navy Treatment Table 6 with oxygen breathing
USN Table 6 at 2.8 ATA with oxygen periods is the standard recompression treatment for AGE and severe decompression sickness.
The documentation required by CMS for hyperbaric oxygen therapy includes all of the following EXCEPT:
Answer: A signed waiver from the patient releasing the facility from liability for oxygen toxicity
CMS does not require a liability waiver; it requires physician evaluation, per-session notes, and documentation of an approved indication for reimbursement.
What is the first step in CHS risk assessment?
Answer: Identifying potential hazards and threats
Risk assessment begins with systematic identification of all potential hazards, forming the foundation for all subsequent analysis.
A diver reports progressive tingling in both legs after surfacing from a deep dive. This bilateral lower extremity paresthesia most likely indicates what type of DCS?
Answer: Spinal cord DCS (Type II), requiring urgent HBOT
Bilateral paresthesias of the lower extremities strongly suggest spinal cord bubble formation affecting the thoracic or lumbar cord, classifying this as Type II (neurological) DCS.
What is the maximum delay between DCS symptom onset and first HBOT treatment still considered likely to provide neurological benefit?
Answer: There is no absolute cutoff; treat as soon as possible even if delayed by hours or days
While earlier treatment is always better, HBOT can still provide benefit in DCS even when delayed by 24 hours or more, particularly for neurological symptoms, and should never be withheld solely due to delay.
The primary reason for maintaining a minimum separation distance between hyperbaric chambers and ignition sources is to:
Answer: Prevent oxygen-enriched exhaust gases from contacting sparks or open flames
Hyperbaric chambers vent oxygen-enriched exhaust that can create a flammable atmosphere near the chamber, making separation from ignition sources essential.
Which condition is treated with US Navy Treatment Table 5 rather than Table 6?
Answer: Mild Type I DCS (pain only) that resolves completely with initial oxygen breathing at 60 fsw
USN TT5 is appropriate for mild Type I DCS (musculoskeletal pain, skin symptoms) that fully resolves during the initial oxygen-breathing period at 60 fsw, indicating a favorable response.
What is evidence-based practice in CHS Infection Control & Prevention?
Answer: Integrating research evidence with expertise and client needs
Evidence-based practice combines research, expertise, and client preferences for optimal outcomes.
What is the physiological rationale for air breaks during hyperbaric oxygen therapy?
Answer: To allow washout of reactive oxygen species and reduce CNS oxygen toxicity risk
Air breaks interrupt continuous oxygen exposure, allowing tissue antioxidant defenses to recover and reducing cumulative risk of CNS oxygen toxicity seizures.
Reactive oxygen species (ROS) generated during HBO2 therapy serve a beneficial role in wound healing by:
Answer: Directly killing bacteria and stimulating fibroblast proliferation
At controlled levels, HBO2-generated ROS act as signaling molecules that enhance bactericidal activity of neutrophils and stimulate fibroblast proliferation and collagen synthesis.
What is a critical safety measure when using hyperbaric oxygen therapy?
Answer: Ensuring non-flammable materials are used
Hyperbaric chambers operate with high concentrations of oxygen, which significantly increases the risk of fire. Oxygen is a powerful oxidizer, making flammable materials ignite much more easily and burn more intensely. Therefore, strictly ensuring that only non-flammable or oxygen-compatible materials are present in and around the chamber is a critical safety measure to prevent catastrophic fires.
A patient presents with arterial gas embolism following central line insertion. After initial stabilization, what treatment table is most appropriate?
Answer: US Navy Treatment Table 6A or extended Table 6
AGE is treated like severe decompression sickness; Table 6A or an extended Table 6 with oxygen extensions is preferred when symptoms are serious or fail to resolve.
Barodontalgia (tooth squeeze) during HBO therapy is most commonly caused by:
Answer: Gas trapped beneath dental restorations, in caries, or under crowns
Gas pockets trapped within dental defects, restorations, or beneath poorly fitting crowns undergo compression and expansion during pressure changes, causing pain or structural injury.
Why is regular review important in CHS risk management?
Answer: Conditions change and new risks emerge requiring updates
Regular reviews ensure assessments remain current as conditions change and lessons from incidents are incorporated.
What is the importance of continuing education for CHS professionals in Patient Assessment & Evaluation?
Answer: Maintaining current knowledge and adapting to industry changes
Continuing education keeps professionals current with developments and best practices while meeting certification requirements.
When evaluating a patient for HBOT, a transcutaneous oxygen measurement (TcPO2) of what value at the wound site best predicts a favorable response to therapy?
Answer: 20–40 mmHg on room air with a rise to above 100 mmHg during HBO
A periwound TcPO2 of 20–40 mmHg on room air that rises above 100 mmHg during HBO (the 'challenge test') predicts a favorable wound healing response.