Which statement best describes the relationship between ambient pressure and bubble formation in DCS?

Which statement best describes the relationship between ambient pressure and bubble formation in DCS?

• A. Reduction in ambient pressure causing formation of gas bubbles from dissolved gases with inadequate elimination after exposure.
• B. Increased ambient pressure dissolving more gas.
• C. Gases convert to liquids under low pressure.
• D. Temperature change is the sole cause.

Answer: (A)

Decompression sickness happens when ambient pressure drops, causing dissolved inert gases (mainly nitrogen) to come out of solution as bubbles. Henry’s law tells us that gas solubility in tissues increases with pressure, so a decrease in pressure during ascent reduces the amount of gas that can stay dissolved. If the body hasn’t off-gassed enough gas during or after exposure, these dissolved gases form bubbles, which can obstruct tissues and blood vessels and lead to DCS symptoms. That’s why the statement describing a reduction in ambient pressure leading to bubble formation from dissolved gases, with inadequate elimination after exposure, best captures the mechanism. The other ideas don’t fit as well: increasing ambient pressure would drive more gas into solution rather than form bubbles; gases don’t convert to liquids simply due to low pressure; and while temperature affects gas solubility, it isn’t the sole cause of bubble formation in DCS.

Decompression sickness happens when ambient pressure drops, causing dissolved inert gases (mainly nitrogen) to come out of solution as bubbles. Henry’s law tells us that gas solubility in tissues increases with pressure, so a decrease in pressure during ascent reduces the amount of gas that can stay dissolved. If the body hasn’t off-gassed enough gas during or after exposure, these dissolved gases form bubbles, which can obstruct tissues and blood vessels and lead to DCS symptoms. That’s why the statement describing a reduction in ambient pressure leading to bubble formation from dissolved gases, with inadequate elimination after exposure, best captures the mechanism.

The other ideas don’t fit as well: increasing ambient pressure would drive more gas into solution rather than form bubbles; gases don’t convert to liquids simply due to low pressure; and while temperature affects gas solubility, it isn’t the sole cause of bubble formation in DCS.