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Posted: Mon Oct 29, 2007 1:43 pm
by Trekker
Hi, Sierra, welcome to the board!

I'm going to take a stab at this and guess that the issues you are having are more blood volume related. The initial responses to ascent to altitude include an increase in hematocrit concentration; however, this is initially less due to increased polycythemia. or red blood cell production, and more due to loss of blood volume brought about by dehydration, due to a number of factors including decreased thirst drive, increased respiration rate (and therefore loss of water through breathing) and an increased diuresis, or urination drive. This loss of blood volume is maintained for the duration of the average backpacker's trip, and is not fully reversed no matter how much you drink ( of course a longer acclimatization is a different story). Once back at sea level, the body will usually get right back to rehydrating in order to reset homeostasis. Therefore, I see the issue as being either 1) you are not rehydrating properly after getting back home and therefore the viscosity of your blood is affecting blood flow and therefore oxygen delivery (if you give blood, they of course tell you to drink lots of fluids, so you have more motivation to drink) or 2) you may be hyperhydrating and diluting your RBC count, which could also affect oxygen delivery. When you exercise, you increase the flow of blood due to increased heart rate and decreased resistance of the blood vessels in the working muscle, so this may explain why you feel good when exercising.

Posted: Tue Oct 30, 2007 7:54 am
by Sierra Maclure
Geat responses to this re-acclimation issue. In the last few years since being post-chemo for breast cancer, it hasn't been that much of an issue. My red (and white) cell production has been permanently decreased. They don't tell you this when their infusing the stuff. This makes me struggle at high altitudes but returning to sea level isn't such a problem. At first I thought I was just getting old until I compared pre & post chemo pre & post hike hemoglobin values. On my trip to Darwin Bench this last summer over Lamark Col (12880), I came home with a 12 hemoglobin. I used to get up to a 15. Oh well, at least I'm still alive, and still sauntering the heart of the Sierra. I figure I'll be up there with a walker eventually. :retard :
Keep truckin'. You guys are lucky. Your normal is a 15 at sea level.
-SM
PS. Sierra Maclure is a name I've taken that just feels right. It has to do with Mt. Maclure in Yosemite. And also, it's great being part of this community. Thanks!

Posted: Tue Oct 30, 2007 12:23 pm
by Trailtrekker06
nice smugmug site, SMcC ! I'll check out more when I get home late.........

Posted: Tue Oct 30, 2007 12:24 pm
by Trailtrekker06
.....lateR ! :)

Posted: Thu Nov 01, 2007 10:33 pm
by Ranboze
I'll agree with Trekker on this one. It usually takes longer than a few days at altitude to increase RBC mass - I don't want to say for sure exactly how long because I'd have to look it up. So it's plausible that the increased Hbg level is a function of dehydration. Sierra Maclure - have you looked at your retic count upon returning? I wonder if the reticulocyte count (baby red blood cells) would be increased in states of acute hypoxemia induced erythropoeisis (RBC production)? I also agree with Trekker about the increased Hbg levels leading to increased viscosity and possibly decreased blood flow and oxygen delivery.

Posted: Fri Nov 02, 2007 10:28 am
by Sierra Maclure
Good point Ranboze. Why didn't I think of that. I think I'll do some pre-and post-retic counts next time I'm up high for awhile, but like I said, I'm not producing red or white cells like I used to (dang). Now we have a machine that counts retics and I don't have to do them by hand in the microscope (yuck). That's probably why it didn't occur to me to do them before. They are such a drag to do that sometimes I feign sleep with my forehead on the occulars. I did think of dehydration as the culprit, but after drinking a ton and still feeling flakey I scratched it as the cause. I've had friends on the same trips that mentioned the same condition and others that had no problems. Hmm... maybe I can get some of my friends to shed some blood and be part of the experiment. :)