In diving, the most common form of barotrauma occurs during which phase?

In diving, the most common form of barotrauma occurs during which phase?

• A. Ascent
• B. Bottom time
• C. Descent
• D. Surface

Answer: (C)

The pressure changes with depth are the key factor in barotrauma. As you descend, the surrounding water pressure increases, so air-filled spaces in the body must be equalized to avoid a pressure difference across their walls. The most common injury in divers is middle-ear barotrauma, which happens when the diver cannot sufficiently equalize the pressure in the middle ear as pressure mounts during descent. If the Eustachian tube can’t open to balance the pressure, the tympanic membrane is subjected to a rapid external pressure increase, causing pain and sometimes rupture. So the phase with the highest risk is descent, when the pressure change is most abrupt. Ascending can lead to other problems, like pulmonary barotrauma if a breath is held, but that’s a different mechanism and less common overall. Surface conditions don’t involve rapid pressure changes, so barotrauma is unlikely there.

The pressure changes with depth are the key factor in barotrauma. As you descend, the surrounding water pressure increases, so air-filled spaces in the body must be equalized to avoid a pressure difference across their walls. The most common injury in divers is middle-ear barotrauma, which happens when the diver cannot sufficiently equalize the pressure in the middle ear as pressure mounts during descent. If the Eustachian tube can’t open to balance the pressure, the tympanic membrane is subjected to a rapid external pressure increase, causing pain and sometimes rupture. So the phase with the highest risk is descent, when the pressure change is most abrupt. Ascending can lead to other problems, like pulmonary barotrauma if a breath is held, but that’s a different mechanism and less common overall. Surface conditions don’t involve rapid pressure changes, so barotrauma is unlikely there.