Decompression illness

Altitude decompression illness (DCI) disorders result from gas bubbles at sites in the body where they do not normally exist. These disorders encompass decompression sickness (DCS), whereby bubbles of inert gas evolve in supersaturated tissues or blood; arterial gas embolism (AGE), due to pulmonary barotrauma, overwhelming respiratory DCS or shunting of venous bubbles through to the arterial circulation; and ebullism, due to vapourization of tissue fluid at extreme altitude. The first half of the chapter focuses on altitude DCS, as pulmonary barotrauma and ebullism are both rare during flight. The second half reviews the principles of DCI management more broadly. The chapter concludes with an overview of brain white matter change, although any relationship of this phenomenon with DCI currently remains uncertain.