A.G.E. Questions and answers

[DocVikingo]

Hi Catherine96821,

Yesterday, Kevrumbo posted, ". . .that would be via a Patent Foramen Ovale (PFO)," to which you responded, "I know what that is....most babies have it and it closes at birth."

I intended to clarify the problem with that later statement in my prior post, but let me reduce it to even simpler terms:

1. All fetuses have a "foramen ovale." It is a critical feature of how their tissues are oxygenated from the placenta since they do not have functioning lungs.

2. No fetuses have a "patent foramen ovale" as by definition it is a cardiac abnormality that does not appear until after birth.

Therefore, saying of PFO that "most babies have it and it closes at birth" makes no sense.

Clear?

Regards,

DocVikingo

 

[Cacia]

thanks.

I was trying to ask a different question.

you are absolutely right....I have not been on the cardiac surgery team for quite a few years now, and I really have no place misusing terminology.

It is clear to me that the opening, while it exists, is not to be termed PFO in the Dive Medicine Forum. My bad.

 

[pickens_46929]

Ok, I am not a doctor or in the medical field, however both close relatives are in cardio care incl. one that specializes in blood diseases and thrombalitics (sp?).

Asked the question about gas bubbles and injury, the comment back was that injury or surgery of any kind could affect it... much like it would increase the risk of clots developing. The specific example was arterial plaque can cause funny things to happen due to turbidity(sp?) - basically a restriction or partial blockage. Affects flow, therefore affects deco.

Not sure about this but it sounded reasonable.

 

[Wildcard]

"capillary beds in the lunch (or through intraparenchymal shunts) "
TSand M, define please. I don't know intraparenchymal shunts. Is that between the A and V capillarys?

 

[lamont]

lunch? i usually have pho...

 

[Wildcard]

Even the best get hungry while typing.....

 

[TSandM]

Even within the lungs, a small amount of the blood doesn't pass through the capillaries to get exposed to gas exchange. This is called "physiologic shunt" and is normal. Basically, the blood passes directly from the venous to the arterial circulation through small vessels which are not actually capillaries (which are vessels in which the blood cells have to pass single file -- vascular "restrictions" as it were; the blood vessels have to take their tanks off to get through).

 

[stardiver]

I would also like to know if having previous surgery of the brain or head injury can make one more susceptible.

Add to that a hit, however undeserved, requiring a few chamber rides during one's OW checkout dives... is it possible that there is some cumulative damage, or perhaps some pre-existing issue from surgery and the first hit that would make one more susceptible?

*

 

[TheRedHead]

Are there "undeserved" occurences of a CAGE? Does choice of breathing gas play a factor (helium vs. nitrox or air). The latest accident has worried me more than any other diving accident I've read about. Can you do everything right and embolize?

 

[Cacia]

lots of rumblings about helium.

I've also been taught by several instructors, that at the end of the dive to hang out and float on the surface for at least two minutes before climbing onto the boat or shore. This allows time for your blood to circulate one complete time and reduce the risk of any of those bubbles growing or causing problems because of the extra exertion.

thanks... makes sense, but I had never heard this.