CHS Oxygen Toxicity & Barotrauma Management 3

Question 1

The Unit Pulmonary Toxicity Dose (UPTD) is used in HBO therapy to track:

Accepted Answer

Cumulative pulmonary oxygen exposure to prevent pulmonary toxicity

Answer

Cumulative carbon monoxide exposure in CO poisoning patients

Answer

Seizure risk from CNS oxygen toxicity

Answer

Nitrogen narcosis risk during treatment

Question 2

What is the most dangerous manifestation of CNS oxygen toxicity for a patient inside a hyperbaric chamber?

Accepted Answer

Grand mal (tonic-clonic) seizure

Answer

Temporary tunnel vision

Answer

Tinnitus

Answer

Mild nausea with diaphoresis

Question 3

A multiplace chamber patient begins having a tonic-clonic seizure. The correct immediate sequence is:

Accepted Answer

Remove oxygen mask, protect patient from injury, then decompress the chamber safely

Answer

Maintain oxygen delivery, protect the patient, and call for emergency help

Answer

Apply physical restraints immediately, then begin emergency decompression

Answer

Remove oxygen mask, administer IV benzodiazepine, and maintain treatment pressure

Question 4

Why does hypercapnia increase the risk of CNS oxygen toxicity during HBO therapy?

Accepted Answer

Cerebral vasodilation from CO2 increases brain oxygen delivery, lowering the seizure threshold

Answer

It increases alveolar oxygen exchange and inspired PO2

Answer

It enhances hepatic oxygen metabolism, increasing circulating free radicals

Answer

It reduces oxygen-hemoglobin affinity, releasing more O2 to brain tissue

Question 5

Inner ear barotrauma during HBO therapy may result in:

Accepted Answer

Permanent sensorineural hearing loss from round or oval window rupture

Answer

Temporary ear fullness that resolves after treatment

Answer

Improved low-frequency hearing from membrane tension changes

Answer

Conductive hearing loss that resolves within 24 to 48 hours

Question 6

How do Type I and Type II decompression sickness differ?

Accepted Answer

Type I involves musculoskeletal and skin symptoms; Type II involves neurological, inner ear, or cardiopulmonary symptoms

Answer

Type I involves neurological symptoms; Type II involves only joint and musculoskeletal pain

Answer

Type I is managed with normobaric oxygen alone; Type II always requires surgical intervention

Answer

Type I occurs only in scuba divers; Type II occurs exclusively in HBO patients

Question 7

A patient reports chest tightness during ascent in a hyperbaric chamber. The most appropriate immediate action is:

Accepted Answer

Stop ascent, encourage slow normal breathing, and assess for pulmonary overpressurization injury

Answer

Continue ascent at the same rate while monitoring the patient

Answer

Increase the ascent rate to shorten the discomfort period

Answer

Administer inhaled bronchodilators before continuing ascent