CHT Oxygen Toxicity & Contraindications 3

Question 1

HBO-induced seizures due to CNS oxygen toxicity are best characterized as:

Accepted Answer

Self-limiting events that resolve when oxygen exposure is reduced

Answer

Life-threatening events requiring immediate airway intubation and resuscitation

Answer

Permanently damaging to brain tissue requiring post-treatment neurological evaluation

Answer

Events that must be prevented by routine antiepileptic premedication for all patients

Question 2

Which intervention is most effective in reducing the cumulative risk of pulmonary oxygen toxicity during a standard HBO treatment course?

Accepted Answer

Implementing scheduled air breaks during each treatment session

Answer

Limiting chamber pressure to a maximum of 2.0 ATA for all treatments

Answer

Administering antioxidant supplements (vitamin C, E) before all treatments

Answer

Reducing treatment frequency to every other day instead of daily sessions

Question 3

A patient with COPD and known CO2 retention (hypercapnia) presents for HBO therapy. The primary concern regarding oxygen toxicity is that hypercapnia:

Accepted Answer

Lowers the seizure threshold, increasing CNS oxygen toxicity risk

Answer

Prevents adequate chamber pressurization in COPD patients

Answer

Blocks oxygen from binding to hemoglobin in the lungs

Answer

Makes ear equalization impossible for the patient

Question 4

When a patient experiences a seizure inside a monoplace hyperbaric chamber, the correct treatment sequence is:

Accepted Answer

Switch to air breathing and perform emergency decompression at the maximum safe rate

Answer

Maintain treatment pressure and administer IV benzodiazepine through the medication port

Answer

Maintain 100% oxygen at treatment pressure until the seizure self-terminates naturally

Answer

Increase pressure to 3.0 ATA to accelerate neurological seizure termination

Question 5

Long-term HBO patients receiving daily treatment courses should be monitored for pulmonary oxygen toxicity primarily using:

Accepted Answer

Periodic spirometry to detect decreases in vital capacity

Answer

Daily arterial blood gas analysis to measure PaO2 levels

Answer

Weekly chest radiographs to detect early inflammatory infiltrates

Answer

Monthly CT scanning of the thorax for early fibrosis detection

Question 6

Which HBO treatment scenario carries the HIGHEST cumulative pulmonary oxygen toxicity risk?

Accepted Answer

120 minutes at 2.4 ATA breathing 100% O2 with no air breaks

Answer

90 minutes at 2.0 ATA breathing 100% O2 with two scheduled air breaks

Answer

45 minutes at 3.0 ATA breathing 100% O2 with one air break

Answer

60 minutes at 2.0 ATA breathing 100% O2 with three scheduled air breaks

Question 7

Which of the following is recognized as a RELATIVE contraindication (not absolute) to HBO therapy?

Accepted Answer

History of prior spontaneous pneumothorax (now resolved)

Answer

Untreated tension pneumothorax

Answer

Active concurrent treatment with bleomycin chemotherapy

Answer

Active uncontrolled life-threatening hemorrhage