CHS Oxygen Toxicity & Barotrauma Management 2

Question 1

Middle ear squeeze (barotitis media) during HBO therapy is caused by:

Accepted Answer

Failure of the Eustachian tube to equalize pressure across the tympanic membrane

Answer

Excessive oxygen delivery to cochlear tissues

Answer

Air bubble formation in the semicircular canals

Answer

Eustachian tube hypertension from rapid ascent

Question 2

Which equalization technique is generally preferred for patients with difficulty clearing their ears during HBO compression?

Accepted Answer

Modified Valsalva (pinch nose and swallow or yawn)

Answer

Forceful standard Valsalva against a closed airway

Answer

Frenzel maneuver with glottis closure

Answer

Toynbee maneuver with nose pinched and swallowing

Question 3

Pulmonary barotrauma during ascent in a hyperbaric chamber is most likely when a patient:

Accepted Answer

Holds their breath while the chamber is decompressing

Answer

Breathes slowly and deeply throughout ascent

Answer

Uses a demand valve mask during treatment

Answer

Yawns frequently to equalize ear pressure

Question 4

Arterial gas embolism (AGE) as a complication of pulmonary overpressurization is the primary treatment:

Accepted Answer

Immediate recompression to 2.8 ATA with oxygen breathing (USN Table 6)

Answer

100% normobaric oxygen by non-rebreather mask only

Answer

Bed rest, IV hydration, and observation

Answer

Aspirin, anticoagulants, and hyperbaric consultation

Question 5

Which paranasal sinus is most commonly affected by sinus squeeze (sinus barotrauma)?

Accepted Answer

Maxillary sinus

Answer

Sphenoid sinus

Answer

Ethmoid sinus

Answer

Frontal sinus

Question 6

Barodontalgia (tooth squeeze) during HBO therapy is most commonly caused by:

Accepted Answer

Gas trapped beneath dental restorations, in caries, or under crowns

Answer

Calcium depletion from tooth enamel under pressure

Answer

Increased pulpal blood flow from vasoconstriction

Answer

Fluoride release from sealants during compression

Question 7

Which condition represents an absolute contraindication to HBO therapy due to significant barotrauma risk?

Accepted Answer

Untreated pneumothorax

Answer

Mild well-controlled asthma

Answer

Mild unilateral conductive hearing loss

Answer

History of childhood otitis media