microparticules

[gkwalt]

I can speak anecdotally, in my field of medicine I see intravenous bubbles all the time. They arise from intravenous injection of medications (even with the carefullest of technique). Granted the bubble load is not as robust as what may be seen in DCS. In the past DCS research was focused on what we could see, bubbles,I believe this new work from Penn is complementing previously done research on a molecular/cellular level.
Another question I have for Dr. Deco: Is DCS a continuum? PFO aside, is the degree of the instigation factor (amount of bubbles?) less in type 1 DCS and much greater in type 2? Or can the same amount of bubbles produce only joint pain in one dive but paralysis in another? Thanks

 

[Dr Deco]

Hello gkwalt :

A Continuum?

The amount of bubble formation in a dive is a continuum depending on the “dose” of nitrogen. [Micronuclei number is another factor.] Those who do not dive at all naturally have no bubbles in their body. A short dive [small nitrogen dose] will yield a few bubbles. If the same individual stays for a longer time at that same depth, more bubbles will be produced.

Where?

If the bubbles are produced in the tissues themselves [nerve tissue, connective tissue], pain or paralysis could result. The degree of pain or paralysis depends [it is believed] on the degree of gas phase separation [i.e., number of bubbles]. In this case, I speak of in situ bubble formation; this is also termed “autochthonous” bubble formation.

Embolization

There isanother case when bubbles move into a tissue from the blood stream. These would be bubbles formed in muscle and fat tissue, dumped into the venous system, and then carried into the arterial circulation through a PFO. The bubbles might go to muscle tissue where probably nothing will happen. Or they could migrate to the spinal cord or brain and cause a stroke [like a blood clot].

In thislatter case, it seems as though the number of bubbles plays a role. A few bubbles are often simply pushed through the brain capillaries and move into the venous system again. Many bubbles cause a plugging and blood flowstops.

In the 1500s,the physician Paracelsus once said “The dose alone determines the poison.” This is somewhat so with decompression bubbles.

Dr Deco :doctor:

 

[Amar]

Hi dr deco,

You mentioned that cerebral air bubble embolisation, if there are only a few bubbles they can be pushed through the vascular bed. I was wondering if there was any evidence to support this as my understanding was that even though bubbles are flexible in shape, due to repelling forced, the deformation of a bubbles shape could not achieve a diameter of less than 10 microns and hence would still get stuck in a capillary.

I wanted to know your thoughts on the idea

Thanks
Amar