Gear/Tips
> Decompression Reference: Red
Blood Cell Rigidity
-----Original Message-----
From: George Irvine [mailto:girvine@bellsouth.net]
Sent: Monday, February 11, 2002 6:39 AM
To: techdiver@aquanaut.com; quest@gue.com
Subject: RE: Red Blood Cell Rigidity
Narcotic level is easy - any increase is more narcotic than no increase.
Impairment starts immediately, and just gets worse.
As for rigidity
due to nitrogen tension, it appears to be relieved by the presence of
helium in the same fashion - the more helium , the less tension.
We have found that
<30% [Helium] is not going to do a whole lot . 25% [Helium] is the
minimum useful range for deco gas, 30 for diving, and then we are talking
<120 feet. For all else we go to at least 35 [% Helium] and prefer
higher.
After thousands,
as in the tens of thousands, of man dive hours in the WKPP doing extreme
exposure mixed gas dives over the course of 16 years , and intensely
over the last 9 years, these have been our findings.
-----Original Message-----
From:
Sent: Monday, February 11, 2002 3:03 AM
To: George Irvine; techdiver@aquanaut.com; quest@gue.com
Subject: Red Blood Cell Rigidity
"High partial pressures of nitrogen cause the red cells to become
rigid and get hung up in capillaries or damage them. The response of
the body to this and the immune response tend to close off the area
. Anyone ( but a dive instructor) can see what that means for decompression."
Hi George & List,
As always, thanks for the info. With respect to red cell rigidity with
a high pp of N2, my knowledge of physiology has dulled somewhat over
the years, but red cells do distort (squash) as they move through smaller
capillaries, which would make the
prospect of increased rigidity of the RBC quite alarming. That is, small
capillaries are smaller than RBC. Hence, it could be that we see RBCs
unable to pass and associated capillary rupture. Do you think there
is a threshold partial pressure where the effect of RBC rigidity becomes
marked, or is there a linear change? I would think there would be an
age variable here as well.
If so, did this (theoretical) threshold partial pressure of N2 (causing
RBC rigidity) influence the GUE recomended mixes?
I realize you are keeping the narcotic values at around or less than
30m. What I am getting at is a "threshold physiologically damaging
pp of N2", as well as a narcotic level. We seem to be able to quantify
a narcotic value (=level). This is fascinating stuff, and would keep
some PhD students going for years.
Regards,
I'm going to send
this quick, B4 I confuse myself any further.............
