Mt. Whitney Portal Store & Hostel Forums General Mt. Whitney Portal Store Message Board Another Thread On Altitude

Bob K, I would give a somewhat different answer. If it's a warm sunny day and everything is going well, the reduced brain function even at the summit of Whitney is not a problem - simply because you don't have much thinking to do. Step, breath, drink and eat a little - life is simple and doesn't matter if you are "impaired". However, if something goes wrong, or you have to make a decision (like keep going or turn back when cumulus clouds start building), then even a relatively small amount of impairment can become an issue.

When people start criticizing big mountain climbers for what appear to be stupid decisions at high altitude, I like to point out that a decision in your warm living room at sea level when you are well fed and rested is very different from a decision at 20,000+ feet when you haven't slept well in days/weeks, are malnourished, hypoxic and cold. I've seen very smart guys unable to figure out relatively simple things due to such impairment.

So it goes on Whitney. Most climbers, especially weekend warriors, have somewhat reduced mental function on Whitney. It may not matter unless there is an important decision or skillfull move needed - and then you don't have that full ability when most needed. It's just something to be aware of as you go higher.

Exactly WA.

Deficits "not noticed" does not mean they are not there.

I learned my own lesson once. Nearly killed myself tripping on gaiters placed on wrong feet. The one (known) time I had the buckles on the inside I snagged my crampons, fell, and arrested a fall. This was at 21,000 so we were pretty dull. The mental dullness and inattention made this simple, mundane chore a potentially life-threatening event. This can easily happen at Whitney altitudes. While I have felt fine on my two Whitney ascents, there are other places where I felt much, much different at the same height.

Mental and physical deterioration at altitude is a continuum and begins at about 5,000 feet.
Harvey

It's always an interesting thread when altitude is the subject.

A few year's back in a similar thread, someone commented that a "weekend warrior" would not retain acclimitization from week to week. I disagreed at the time based on my own performance at altitude over successive weekends (fitness was not an issue as I was very fit at the time). I recall asking Bob R whether he ever had altitude issues (assuming the answer would be no based on how much time he spends in the mountains) and got the answer I expected.

I've been up for 2-3 days per week for the past month, or so, and my performance has been getting better and better (some related to increased fitness), but the good thing is that I have not experienced any AMS symptoms on the last two trips.

My non-scientific conclusion would be that there is a carry-over and not a rapid decline in acclimitization levels.

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I'm curious as to whether there is a relationship between the pulsox reading and the partial pressure(?) at altitude? I ask because HL seemed to be able to predict what the reading should be. I would assume that the reading would be impacted by a person's natural ability to acclimitize more rapidly?

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On the lighter side: has anyone else come across what I like to call the low altitude headache. I seem to occasionally get a headache on returning home. Wait a second, maybe it's related to the dirty air, or stress related to having to return to work.

> has anyone else come across what I like to call the low altitude headache.

Your question reminded me of this:
<a href=/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004276>Post-altitude headache?</a>

But his sounded different than yours.

Richard, yes, there is a relationship between partial pressure of oxygen and O2 sat. Thankfully, it is not linear (see bottom) because of the way hemoglobin binds, carries and releases oxygen.

Average levels can be quoted and used as a rough guide. But average reflects a range affected by such parameters as degree of acclimatization, age, sex, fitness, respiratory response to altitude, cardiac output, hydration, blood ph that is higher with hyperventilation, pulmonary artery pressure response to hypoxia, type of hemoglobin, intracellular responses, etc. It is much more complex than just making "thicker" blood.

Evening out all this, O2 sat may be used as a comparison. The number X is arguable but if person A has an O2sat that is X amount lower than everyone else...in the same situation!!!... then there probably is a problem whether symptoms are overt or just around the corner.

The following numbers I found from one limited-info source are a lower than what I have personally witnessed for average on the mountain. Be careful with interpretation, these numbers look like acute altitude(or hypobaric chamber test), probably acute altitude exposure and unacclimatized. That's the whole problem with numbers...what's the situation?

altitude in ft/ partial pressure O2/ O2 sat

0 / 94 / 97
5,000 / 66 / 92
10,000 / 53 / 85
15,000 / 44 / 75
20,000 / 38 / 65

The other source looks more like what I have seen personally, with acclimatization, at rest, and not altitude-ill.

altitude in feet /o2 sat
3281 / 99
11,483 / 93
14,764 / 88
18,044 / 80
21,320 / 75


Hope this helps, Harvey

WAclimber,
Re: "When people start criticizing big mountain climbers for what appear to be stupid decisions at high altitude, I like to point out that a decision in your warm living room at sea level when you are well fed and rested is very different from a decision at 20,000+ feet when you haven't slept well in days/weeks, are malnourished, hypoxic and cold. I've seen very smart guys unable to figure out relatively simple things due to such impairment."

While reading your message, I felt like I was nodding my head in agreement. It wasn't until a day later that a question popped into my mind regarding another aspect of that situation. How does that situation differ from drunk driving? They seem to be similar.

Bob K-

Interesting question. I've seen estimates that 50% of all car accidents have alcohol as a contributing factor, so clearly drinking and driving is an incredibly stupid thing to do. Obviously, drinking is not inherent in driving. Hypoxia, on the other hand is inherent in climbing big mountains. Other than carrying oxygen, which is generally not considered to be necessary below the mid-twenties, mountain climbing involves some degree of hypoxia and the resulting mental impairment. So in cars, alcohol reduces the margin of safety and increases risk just as reduced oxygen does in the mountain. However, alcohol is a totally avoidable risk in driving while mild hypoxia is an effectively unavoidable risk in mountaineering. We can manage this mountaineering risk by acclimatizing, getting fit before we go, climbing with experienced climbers when going to harder or higher mountains, being aware of our reduced capabilities at higher altitudes and making some decisions (like a turn-around time) lower on the mountain and then sticking to them up high.

Re: "However, alcohol is a totally avoidable risk in driving while mild hypoxia is an effectively unavoidable risk in mountaineering."

Would this be an "avoidable risk"?:

"... when you haven't slept well in days/weeks, are malnourished, hypoxic and cold. I've seen very smart guys unable to figure out relatively simple things due to such impairment."

Precisely my point. If you want to climb big mountains, some hypoxia and mental impairment is an inherent and unavoidable risk. The only way to avoid this risk entirely is to not climb, which many of us on this board believe would materially reduce our quality of life. You can also stick to lower mountains as this reduces the risk. While Whitney is a big mountain, the summit of Whitney is lower than the base camp of Everest.

"Errors of cognition and judgment, such as in the environment we faced above 6,700m (22,000ft), may cause as many deaths as more obvious factors. Recognizing this mental decline can be difficult."

That was actually the whole point of the Brains and Video Games at High Altitude article. Mentation suffers on both the serious and frivolous end.

Need not to go that high. Subtle changes begin at 5,000, as discussed.

Harvey