Certified Hyperbaric Technologist Test CHT Decompression Sickness and Gas Embolism Treatment

Question 1

The standard US Navy treatment table for serious decompression sickness (Type II) or arterial gas embolism is:

Accepted Answer

USN Treatment Table 6

Answer

USN Treatment Table 5

Answer

USN Treatment Table 3

Answer

USN Treatment Table 9

Question 2

Type I decompression sickness (DCS) is characterized by:

Accepted Answer

Joint pain, skin mottling, or lymphatic symptoms without neurological involvement

Answer

Paralysis, unconsciousness, or cardiopulmonary compromise

Answer

Arterial gas embolism with retinal involvement

Answer

Pulmonary over-inflation and pneumothorax only

Question 3

Arterial gas embolism (AGE) most commonly occurs as a result of:

Accepted Answer

Pulmonary over-inflation with gas entering pulmonary veins during ascent

Answer

Nitrogen saturation exceeding tissue absorption limits

Answer

Oxygen toxicity damaging pulmonary capillaries

Answer

Mechanical trauma to a joint space at depth

Question 4

First aid for a suspected DCS or AGE victim before reaching a recompression chamber includes:

Accepted Answer

100% normobaric oxygen, IV fluids, and supine positioning

Answer

Immediate cold water immersion to slow bubble expansion

Answer

Oral aspirin to prevent clotting around gas bubbles

Answer

Rebreathing into a paper bag to raise CO2

Question 5

The 'chokes' in decompression sickness refers to:

Accepted Answer

Pulmonary DCS with chest pain, coughing, and respiratory distress from venous gas emboli in the lungs

Answer

Laryngospasm caused by aspiration during rapid ascent

Answer

CNS DCS affecting the brainstem respiratory center

Answer

Pneumothorax following pulmonary over-inflation

Question 6

If a patient's neurological DCS symptoms worsen during USN Table 6, the recommended action is:

Accepted Answer

Extend the table by adding oxygen periods at 60 fsw and consult the diving medical officer

Answer

Immediately abort the table and surface the patient

Answer

Switch to Table 5 as a shorter alternative

Answer

Increase pressure beyond 60 fsw to 165 fsw