CHS Pharmacology & Medication Management 2 — Questions and Answers
Question 1: Which medication class is contraindicated in hyperbaric oxygen therapy due to its ability to lower the seizure threshold in an oxygen-enriched environment?
- Beta-blockers
- Fluoroquinolone antibiotics (Correct answer)
- ACE inhibitors
- Proton pump inhibitors
Correct answer: Fluoroquinolone antibiotics
Fluoroquinolones lower the seizure threshold and should be withheld before HBO sessions due to increased CNS oxygen toxicity risk.
Question 2: Disulfiram (Antabuse) is a concern in HBO therapy primarily because it:
- Increases cardiovascular risk during compression
- Inhibits superoxide dismutase and worsens oxidative stress (Correct answer)
- Causes severe tympanic membrane rupture risk
- Reduces plasma oxygen solubility
Correct answer: Inhibits superoxide dismutase and worsens oxidative stress
Disulfiram inhibits superoxide dismutase, impairing the patient's ability to detoxify reactive oxygen species generated during HBO therapy.
Question 3: A patient on insulin pump therapy is scheduled for HBO. What is the recommended management of the insulin pump during treatment?
- Continue pump at normal rates throughout the session
- Suspend the pump and remove it from the chamber (Correct answer)
- Reduce basal rate by 50% during the session
- Switch to oral hypoglycemics on treatment days only
Correct answer: Suspend the pump and remove it from the chamber
Insulin pumps contain electronic components and gas-filled reservoirs that are incompatible with hyperbaric pressure and must be removed before chamber entry.
Question 4: Cisplatin (a chemotherapy agent) in combination with HBO therapy primarily raises concern for:
- Nephrotoxicity potentiation
- Enhanced pulmonary oxygen toxicity (Correct answer)
- Reduced tumor oxygenation
- Hypertensive crisis during compression
Correct answer: Enhanced pulmonary oxygen toxicity
Cisplatin sensitizes lung tissue to oxygen toxicity, increasing the risk of pulmonary oxygen toxicity when combined with HBO therapy.
Question 5: Which topical agent is absolutely prohibited inside a hyperbaric chamber due to fire hazard?
- Normal saline wound irrigant
- Petroleum-based ointments (Correct answer)
- Silver sulfadiazine cream
- Hydrogel wound dressings
Correct answer: Petroleum-based ointments
Petroleum-based products are highly flammable and absolutely contraindicated inside hyperbaric chambers because oxygen-enriched environments dramatically lower ignition thresholds.
Question 6: A patient receiving methotrexate for rheumatoid arthritis is referred for HBO. The primary concern regarding this medication is:
- It accelerates nitrogen narcosis
- It increases pulmonary oxygen toxicity risk (Correct answer)
- It causes excessive vasoconstriction during treatment
- It reduces red blood cell oxygen-carrying capacity
Correct answer: It increases pulmonary oxygen toxicity risk
Methotrexate can cause pulmonary toxicity, and combined with high-pressure oxygen, the risk of pulmonary oxygen toxicity is significantly increased.
Question 7: Epinephrine auto-injectors (EpiPens) brought into a hyperbaric chamber by a patient pose a risk because:
- Epinephrine degrades under elevated pressure
- The pressurized auto-injector device may malfunction or discharge (Correct answer)
- Epinephrine lowers oxygen seizure threshold
- Epinephrine reacts with hyperbaric oxygen to form toxic metabolites
Correct answer: The pressurized auto-injector device may malfunction or discharge
Pressurized auto-injector devices can malfunction, accidentally discharge, or rupture under hyperbaric conditions, posing both an injection hazard and a fire risk.
CHS Pharmacology & Medication Management 2
Which medication class is contraindicated in hyperbaric oxygen therapy due to its ability to lower the seizure threshold in an oxygen-enriched environment?