Venous gas bubbles in breath hold divers remained a focus of researchers this year, with a notable presentation coming from Danilo Cialoni and his EDAN team1. At EUBS 2017 they presented the extension of study previously reported and described in this blog. After discovering post-dive VGE in one breath hold diver, they studied VGE in 37 elite breath hold divers during their training in 42 meter deep pool with water temperature of 32 oC.
EUBS 2017 has left us with more questions than answers, on the topic of post-dive bubbles.
Ballestra presented the preliminary results of an exploratory study of the effects of sonic vibrations on post-dive venous gas emboli detected by transthoracic echocardiography1. (more…)
Decompression sickness has been the suspected cause of the post-dive symptoms of brain injury in breath-hold divers for a long time, and the quest for the proof of culprit has been ongoing, but without success. In the meantime, many possible explanations of neurological symptoms in breath-hold divers were proposed, including in-situ bubble development, lung barotrauma and consequent gas embolization, atherosclerosis, small vessel disease, transitory extreme elevation of blood pressure, and repeated hypoxic injury. (more…)
Are some divers prone — or resistant — to gas bubbles after diving?
Decompression sickness (DCS), which may occur in divers after decompression from a dive, is dependent on the combined dose of gas saturation during the dive and the rate and magnitude of decompression. However, there is a great variability of outcomes in subjects exposed to the same dive profiles. The variability decreases as the severity of exposure increases.
DCS is correlated with the degree of venous gas emboli (VGE), or “bubbles”, in circulation after a dive. Generally, the higher the VGE grade (more bubbles) the greater the probability of DCS, and vice versa. Similar to DCS, there is a great variance in the probability of VGE appearing postdive. Some researchers who practice VGE detection have hinted that some divers bubble after most dives and may exhibit a high bubble grade (HBG) and others tend not to bubble at all or rarely exhibit HBG. The former are often labeled as bubblers (or high bubblers), while the latter are labeled as nonbubblers (or low bubblers).