Question about compression & stress

[Oxy]

I have only been a member for a short while and have read threads regarding age and diving. Also I have noticed in the accidents and incidents forum, problems with heart related indications.
My question is this. Is there a relation (any studys) between BAR pressure and increased blood pressures. Does the compression cause restricted veins/arteries (tourniquet like) issues leading to heart stress?

 

[DocVikingo]

Hi Oxy,

As you may recall from your basic certification training classes, the changes in ambient pressure inherent in SCUBA only meaningfully impact air-filled spaces (e.g., lungs, middle ears, sinuses). Liquids are compressible to only the most insignificantly minuscule degree at the pressures involved in recreational SCUBA and as such fluid-filled spaces like eyes, veins and arteries are essentially unaffected.

Now, immersion alone does result in central blood pooling with an initial rise in both cardiac output and arterial blood pressure, although these are somewhat counteracted by increased urination. However, this an entirely different matter.

Regards,

DocVikingo

 

[Dr Deco]

Hello Oxy :

Pressure of the seawater is transmitted equally to the body. The blood pressure will not rise from ambient pressure alone.


Q: If I am cut underwater, will my blood spurt out?
A: No.


Q: If I am cut underwater, will the sea water rush in?
A: No

Dr Deco

 

[Thalassamania]

But if you are cut underwater, your blood will not look red. It will look green in recreational diving ranges, really weird.

 

[DocVikingo]

But if you are cut underwater, your blood will not look red. It will look green in recreational diving ranges, really weird.

The perceived color of objects u/w changes based on the "ROY G. BIV" order of the spectrum. The deeper you go, the more blue, then indigo/violet, in appearance. This is gradual and overlapping, so when the "red is gone" that doesn't mean it's now orange, and so on. For example, at >10', most red is gone, as is some of the orange and yellow. The following website is illustrative: Color Underwater.

Many objects below ~30' will appear dark green, then shade to dark blue/indigo to black with increasing depth. If a diver were to be bleeding beyond ~30' the blood would appear green-black.

Regards,

DocVikingo

 

[Oxy]

But if you are cut underwater, your blood will not look red. It will look green in recreational diving ranges, really weird.

Live long and prosper :alien:

 

[Oxy]

I was actually curious about what would increase blood pressure to cause apparent heart attacks while diving. I learned to swim underwater before I learned to swim (loose term) ontop cause I was skin and (lead) bones and sank. So I swam underwater and it was quite easy not having to try to stay on the surface so I don't see physical stress being a factor.
I guess maybe then it could be sudden fear (skock) factor. I know my heart would pound if a large object loomed out of the darkness when I was preoccupied with something else. Especially if my wardrobe resembled it's favorite food.

 

[DocVikingo]

I was actually curious about what would increase blood pressure to cause apparent heart attacks while diving.

Hi Oxy,

From post #2 above:

Immersion results in central blood pooling with an initial increase in heart rate, decrease in stroke volume and rise in arterial blood pressure, although these are somewhat attenuated by increased urination over time.

Regards,

DocVikingo