Certified Hyperbaric Technologist Test CHT Hyperbaric Medicine and Indications 3 — Questions and Answers
Question 1: Which condition is an ABSOLUTE contraindication to hyperbaric oxygen therapy?
- Untreated tension pneumothorax (Correct answer)
- Controlled diabetes mellitus
- Chronic stable hypertension
- A healed surgical scar
Correct answer: Untreated tension pneumothorax
An untreated pneumothorax can convert to a life-threatening tension pneumothorax during decompression, making it an absolute contraindication.
Question 2: A relative contraindication to HBO due to risk of pulmonary oxygen toxicity and air trapping is:
- Severe chronic obstructive pulmonary disease with bleb formation (Correct answer)
- Mild seasonal allergies
- A history of appendectomy
- Well-controlled hypothyroidism
Correct answer: Severe chronic obstructive pulmonary disease with bleb formation
Bullous COPD raises the risk of air trapping and barotrauma, making it a relative contraindication requiring caution.
Question 3: Which medication is classically contraindicated during HBO because it can cause severe pulmonary toxicity with high oxygen exposure?
- Bleomycin (Correct answer)
- Acetaminophen
- Amoxicillin
- Metformin
Correct answer: Bleomycin
Bleomycin combined with high oxygen tension increases the risk of fatal pulmonary fibrosis.
Question 4: Central nervous system oxygen toxicity during HBO most characteristically presents with:
- A grand mal seizure (Correct answer)
- Gradual hair loss
- Slowly rising blood pressure over days
- Chronic joint pain
Correct answer: A grand mal seizure
CNS oxygen toxicity (the Paul Bert effect) can manifest abruptly as a generalized tonic-clonic seizure.
Question 5: The most common adverse effect experienced by patients during hyperbaric compression is:
- Middle ear barotrauma (Correct answer)
- Permanent vision loss
- Cardiac arrest
- Acute kidney failure
Correct answer: Middle ear barotrauma
Failure to equalize middle ear pressure during compression makes aural barotrauma the most frequent HBO complication.
Question 6: Reversible myopia (temporary worsening of nearsightedness) after multiple HBO sessions is attributed to:
- Oxygen-induced changes in the lens of the eye (Correct answer)
- Permanent retinal detachment
- Optic nerve transection
- Increased intracranial pressure
Correct answer: Oxygen-induced changes in the lens of the eye
Prolonged HBO can cause reversible lens changes producing transient myopia that usually resolves after treatment ends.
Question 7: A patient with a fever before HBO treatment poses an increased risk of which complication?
- CNS oxygen toxicity seizure (Correct answer)
- Middle ear infection only
- Permanent deafness
- Reduced wound healing
Correct answer: CNS oxygen toxicity seizure
Fever lowers the seizure threshold, increasing susceptibility to CNS oxygen toxicity, so treatment may be delayed.
Certified Hyperbaric Technologist Test CHT Hyperbaric Medicine and Indications 3
Which condition is an ABSOLUTE contraindication to hyperbaric oxygen therapy?