IDC Dive Physiology & Medical Considerations 2

Question 1

Middle ear squeeze (barotrauma) during descent is most directly caused by:

Accepted Answer

Failure to equalize pressure in the middle ear space

Answer

Middle ear squeeze occurs when a diver fails to equalize the air space in the middle ear to match increasing ambient pressure during descent, creating a pressure differential that damages tissue.

Question 2

A diver who ascends too rapidly may develop arterial gas embolism (AGE). Which symptom would most strongly suggest AGE rather than DCS?

Accepted Answer

Sudden loss of consciousness or neurological symptoms immediately upon surfacing

Answer

AGE typically presents immediately upon or within minutes of surfacing with sudden, severe neurological symptoms because air bubbles enter the arterial circulation and can travel to the brain.

Question 3

Which medical condition is an absolute contraindication to recreational scuba diving?

Accepted Answer

Spontaneous pneumothorax (history of)

Answer

A history of spontaneous pneumothorax is an absolute contraindication because it indicates lung tissue susceptibility to rupture, making lung overexpansion injury highly likely during ascent.

Question 4

The Valsalva maneuver is used by divers to equalize ear pressure. A potential risk of performing it too forcefully is:

Accepted Answer

Inner ear barotrauma or round window rupture

Answer

Forceful Valsalva can rupture the round or oval window of the inner ear, causing permanent hearing loss or vertigo.

Question 5

Carbon monoxide (CO) contamination in a scuba cylinder is most commonly caused by:

Accepted Answer

Improper positioning of the compressor intake near exhaust fumes

Answer

CO enters the air supply when a compressor intake is positioned near engine exhaust fumes, allowing combustion byproducts to be compressed into the tank.

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IDC Dive Physiology & Medical Considerations 2