Venous gas embolism (VGE), or bubbles, in divers postdive indicates that their decompression was too fast, their bodies became supersaturated and free gas emerged from solution in tissues. The occurrence of free gas is considered a necessary condition for decompression sickness (DCS), which can happen even without VGE. However, the presence of VGE increases the number and types of possible harms to the body and thus the probability of DCS.
A number of studies indicate variability in proneness to DCS among divers; however, the question of whether divers who have suffered DCS produce bubbles more readily in general has not been answered yet. To answer this question, researchers would need to identify “bubblers” and “nonbubblers” and observe the outcomes of their dives over some period of time, which would require a lot of resources and time. (more…)
Biological organisms maintain their functional integrity in varying environmental conditions through the activity of the innate immune system and controlled inflammation. During scuba diving, divers are exposed to greater than usual environmental changes, which challenges the entire body. The circulatory system is specifically stressed with an elevated partial pressure of oxygen and by decompression-induced gas bubbles on ascent to the surface. When the stress caused by the pressure changes exceeds a certain threshold, a variety of symptoms may occur after return to the surface — this is usually called decompression sickness (DCS).
DCS has been associated with the presence of a free gas phase in blood and tissues but we know little about the biological pathways and processes involved. While involvement of immune and inflammation cells and processes has been indicated previously, measurable changes are rarely present in asymptomatic divers, making it difficult to study the transition of physiological adaptive stress response into maladaptive or pathological reactions leading to loss of organ functions. We have reported in this blog about recent microparticle studies that may potentially shed more light on this gray area.