Certified Hyperbaric Technologist Test CHT Hyperbaric Pharmacology 1 — Questions and Answers
Question 1: How does hyperbaric oxygen therapy enhance the action of antibiotics such as aminoglycosides?
- HBO increases oxygen tension in tissue, restoring the oxygen-dependent transport needed for antibiotic uptake (Correct answer)
- HBO directly kills bacteria without antibiotic assistance
- HBO raises chamber temperature, activating antibiotic molecules
- HBO reduces kidney clearance, increasing antibiotic serum levels
Correct answer: HBO increases oxygen tension in tissue, restoring the oxygen-dependent transport needed for antibiotic uptake
Aminoglycosides require oxygen-dependent active transport into bacteria; HBO restores this mechanism in hypoxic infected tissue.
Question 2: Bleomycin chemotherapy is considered a relative contraindication for HBO because it:
- Sensitizes the lungs to oxygen toxicity (Correct answer)
- Crosses the blood-brain barrier more rapidly under pressure
- Causes chamber material degradation
- Increases CNS seizure risk at therapeutic pressures
Correct answer: Sensitizes the lungs to oxygen toxicity
Bleomycin causes pulmonary fibrosis, and HBO can exacerbate this by increasing oxidative stress in already damaged lung tissue.
Question 3: Why should insulin-dependent diabetics have their insulin dosing evaluated before a course of HBO treatments?
- HBO enhances glucose uptake and insulin sensitivity, potentially causing hypoglycemia (Correct answer)
- HBO degrades insulin molecules in the bloodstream
- HBO increases glucagon secretion throughout the session
- HBO accelerates hepatic glucose production
Correct answer: HBO enhances glucose uptake and insulin sensitivity, potentially causing hypoglycemia
HBO increases insulin sensitivity and promotes cellular glucose uptake, which can lower blood glucose significantly in diabetic patients.
Question 4: Cisplatin (a chemotherapy drug) combined with HBO is concerning because:
- It increases the risk of both renal toxicity and ototoxicity under hyperoxic conditions (Correct answer)
- It prevents neovascularization stimulated by HBO
- It directly inhibits oxygen binding to hemoglobin
- It lowers the pressure tolerance of the chamber equipment
Correct answer: It increases the risk of both renal toxicity and ototoxicity under hyperoxic conditions
Cisplatin's nephrotoxic and ototoxic effects can be exacerbated by the oxidative stress associated with HBO therapy.
Question 5: Which statement about HBO and anticoagulants (e.g., warfarin) is correct?
- HBO may enhance anticoagulant effects, requiring INR monitoring (Correct answer)
- HBO neutralizes anticoagulants, requiring dose increases
- Warfarin is an absolute contraindication to HBO
- No interaction exists between HBO and anticoagulants
Correct answer: HBO may enhance anticoagulant effects, requiring INR monitoring
HBO can affect platelet function and coagulation pathways, necessitating careful INR monitoring in patients on anticoagulants.
Question 6: Which class of drugs lowers the CNS oxygen toxicity threshold when combined with HBO?
- Tricyclic antidepressants (Correct answer)
- Beta blockers
- ACE inhibitors
- Proton pump inhibitors
Correct answer: Tricyclic antidepressants
Tricyclic antidepressants lower the seizure threshold and can increase the likelihood of CNS oxygen toxicity during HBO therapy.
Certified Hyperbaric Technologist Test CHT Hyperbaric Pharmacology 1
How does hyperbaric oxygen therapy enhance the action of antibiotics such as aminoglycosides?