Are some divers more prone to bubble formation than others?+

[drrich2]

The most compelling argument favoring the bubble, or microbubble, paradigm is that recompression frequently provides immediate relief of some or all symptoms. It “seems” plausible that biochemical changes might result from dissolved gas coming out of solution/tissues, but less probable that the variety of DCS symptoms would be reversed by compression so quickly. That argues that bubbles at least play a significant role.

I'd wondered about that. Especially since some people who go to the chamber go back the next day for another round, when it seems like based on surface intervals in regular diving, surely we ought to clear our bubbles pretty well by that time!!! Reading in The Complete Diver, I think it was, it was pointed out that when you go in a recompression chamber, you also get subjected (even if only due to pressure) a higher partial pressure of O2 than breathing room air at 1 atm, and people with possible DCS are often treated on the boat with O2 with some fast (at least temporary) benefit.

Is this really surprising to anyone? In my day job we used to build infusion pumps for IV therapies. Bubble formation in the tubing was significantly impacted by the chemistry of the tubing and more importantly by the surface roughness. Lipid coatings and lipid based drugs were much more trouble than hydrophilic surfaces. Surface roughness was also important, very smooth surfaces were bad, slightly rough surfaces were better, and surfaces with significant roughness was bad again. It would be interesting to look at blood chemistry/cholesterol particles in the bubblers vs. the non-bubblers, I would expect that they would be correlated

Leading me to wonder what role, if any, plaque build-up in the endothelial lining of blood vessels might play a role.

CONCLUSIONS:
Having observed a 24-h preflight interval, the majority of divers did not develop bubbles during altitude exposure; however, it is intriguing to note that the same subjects who developed significant amounts of bubbles after every dive showed equally significant bubble grades during in-flight echocardiography notwithstanding a correct PFSI. This indicates a possible higher susceptibility to bubble formation in certain individuals, who may need longer PFSI before altitude exposure after scuba diving."

And I wondered whether decompression illness symptoms in bubble-prone people might have led to current NDL limits, and perhaps people who are tested and aren't prone to bubbles might turn out to be adequately safe for shorter intervals.

Richard.

 

[Akimbo]

I'd wondered about that. Especially since some people who go to the chamber go back the next day for another round, when it seems like based on surface intervals in regular diving, surely we ought to clear our bubbles pretty well by that time!!! ....

Recompression treatments after the initial have a dramatically diminishing return in terms of dissolved gas elimination. However, the dramatically elevated PPO2 appears to be beneficial like in so many other hyperbaric Oxygen treatments.

IF you accept that that gas coming out of solution/tissues too fast can cause physical trauma to those tissues, then super-oxygenation is “presumably” beneficial. There’s a lot we don’t really know.

 

[dreamdive]

Actually the idea of subsequent hyperbaric oxygen treatments are less due to bubble reduction than allowing increased oxygen dissolution in the blood plasma. The hypothesis is that secondary injury may cause tissue swelling and clogging of platelets causing platelet plugs in the distal tissues. Thereby, oxygen that is bound to hemoglobin being unable to sufficiently oxygenate those tissues. Oxygen dissolved in plasma is still able to bypass those areas of stricture and reduces, prevents, reverses ischemia.

C