Which scenario presents the highest risk for AGE (Arterial Gas Embolism)?

Breath-hold during ascent is recognized as the scenario presenting the highest risk for Arterial Gas Embolism (AGE) due to the physiological changes that occur when divers are ascending from depth. During ascent, the pressure around the diver decreases, which can cause any gases dissolved in the blood (primarily nitrogen during diving) to come out of solution and form bubbles. When a diver holds their breath while ascending, the expanding air within the lungs can lead to over-expansion and rupture of the lung tissue. This rupture can allow air to escape into the bloodstream, thus creating an arterial gas embolism as bubbles travel through the circulatory system to vital organs, including the brain.

In contrast, breath-holding during descent does not pose the same immediate risk for AGE. Inert gas bubbles in the body may contribute to decompression sickness but are less directly connected to the process of AGE compared to breath-holding during ascent. Overexertion while diving, while it can lead to increased physiological stress and may increase the likelihood of other diving-related incidents, does not directly correlate with the specific mechanism of AGE as the act of holding one’s breath during ascent does.