Certified Hyperbaric Technologist Test CHT Decompression Sickness and Gas Embolism Treatment 3

Question 1

A diver surfaces unconscious after an emergency ascent. The most likely diagnosis is:

Accepted Answer

Arterial gas embolism (AGE) from pulmonary barotrauma

Answer

Type I DCS from nitrogen supersaturation

Answer

CO poisoning from contaminated tank air

Answer

Salt water aspiration causing laryngospasm

Question 2

What distinguishes spinal DCS from AGE clinically?

Accepted Answer

Spinal DCS typically has a slower onset minutes to hours after surfacing, while AGE presents within seconds to minutes

Answer

Spinal DCS always includes unconsciousness; AGE does not

Answer

AGE affects only the lower extremities; DCS affects only the brain

Answer

Both have identical onset timing and cannot be clinically distinguished

Question 3

The purpose of oxygen breathing during decompression stops in USN treatment tables is to:

Accepted Answer

Accelerate inert gas (nitrogen) elimination and reduce total treatment time

Answer

Prevent oxygen toxicity by maintaining high oxygen tension

Answer

Allow the inside tender to breathe air without decompression obligation

Answer

Neutralize any residual CO from prior treatment

Question 4

The 'D10' endpoint in DCS treatment refers to:

Accepted Answer

No residual symptoms at the end of the hyperbaric treatment table

Answer

Reduction of symptoms by at least 10% over baseline

Answer

Completion of 10 consecutive treatment sessions

Answer

10 minutes of oxygen breathing at final decompression stop

Question 5

After a successful Table 6 treatment for DCS, the patient should be advised to:

Accepted Answer

Avoid flying or diving for a minimum of 72 hours and follow up with a diving physician

Answer

Resume normal diving within 24 hours if asymptomatic

Answer

Increase hydration only and return to full activity immediately

Answer

Complete 30 days of daily HBO treatments as a follow-up

Question 6

Spinal cord DCS is most commonly seen in which segment of the spinal cord?

Accepted Answer

Thoracic and lumbar (lower extremity weakness, bladder dysfunction)

Answer

Cervical (neck pain and arm weakness only)

Answer

Medullary (brainstem symptoms only)

Answer

Sacral (isolated bladder dysfunction without motor loss)