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matisse
climber
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May 15, 2008 - 01:27pm PT
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Happy to help, I'm a bit under the gun at the moment, so can we focus it a bit? which parts are you particularly interested in? There is a substantial body of scientific literature.
I assume you are not adverse to reading the actual cites and don't just want some random www link.
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Doug Robinson
Trad climber
Santa Cruz
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May 15, 2008 - 01:49pm PT
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Apogee,
Glad you're interested. I too am unable to help right now. Barely caught your post as I head out to a meeting.
Unfortunately, my information has come chiefly in lectures at Mountain Medicine conferences from researchers like Peter Hackett and David Shlim (Schlim? -- sp?). So, while I am confident of the info, I too would have to dig for source citings.
I suggest you try googling their names. both work for Himalayan Rescue Association. Hackett, I last heard, was in Grand Junction, CO. He did a bunch of his research while parked at the 14,000 foot camp on Denali, treating passing climbers. both guys have manned the hospital at Pheriche at 14,000 feet on the trail to Everest Base Camp.
I know there are some new books too that would likely have summaries and references, but I have not looked at them.
Sorry not to be more help. If you get references, perhaps you could post up here. Thanks!
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Festus
Social climber
Enron by the Sea
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May 15, 2008 - 03:02pm PT
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Ah, the perils of popping off!
Doug,
Ironically, I think we’re on almost exactly the same page here, because I’ve read enough of your stuff to firmly and honestly believe that the way you handle AMS risk/prevention/treatment for your clients isn’t a conflict of interest. And while you couldn’t get me to try Diamox as a preventive, if I suddenly felt the symptoms coming on I’d be damn grateful you had taken the time to educate me on the drug and have it on hand. In that situation, I suspect I’d take it in a heartbeat, and even if it didn’t work I’d be impressed, grateful, and aware that you had gone above and beyond in trying to ensure a great experience for me. So, I should have separated you and your personal guiding philosophy (and actions) from my rant. I didn’t, and I owe you an apology on that score. But my knee-jerk reaction to this whole topic still seems right on to me.
There is an inherent conflict of interest in a guide giving Diamox (or stronger prescrip drugs) as a preventative. The fact that you, personally, handle this thoughtfully and well doesn’t erase that potential conflict (and abuse) for other guides or individuals. And while it wasn’t your intent or maybe any posters intent here, what’s clearly being implied/suggested through the course of this thread is this:
Don’t have time to do it properly? No worries, there’s a shortcut! Dose up and go for it!
I, like you, am absolutely convinced that the only way to save what remains of our wilderness (and wilderness area climbs) is to get more people out there and up there to appreciate it and value it. And, speaking for myself, I also believe that shortcutting that process dilutes the experience--too much, I would argue--and hence the perceived value of the lands/climbs experienced. For me, if AMS slapped me down on a peak-bagging trip, I’d go learn a little more about it (which, in fairness, is all the original poster here probably meant to do) and then build in an extra day or two of acclimatization next trip. That would make for a much better, and more rewarding, second trip and even a strengthened appreciation for the first one. All of which strengthens the bond with, and appreciation for, the place itself.
***
Martin Litton, Grand Canyon dory pioneer and strong advocate of taking the time to float/row the entire stretch of river possible there, was asked what he suggested if one didn’t have the two weeks or so necessary to do the entire canyon by oar power only. His advice: “Find a shorter river.” Shortening that stretch of the Colorado by adding an outboard motor was unthinkable for him. And call it a stretch if you like but I think Litton’s sentiment fits here.
***
As for Elizabeth Hurley, she just emailed me to say that even if my album went double-platinum and I went yard in Wrigley to win game seven, I’d have no chance without a pill that would turn me into Sean Connery circa Goldfinger. There was some hope in this regard when, in brief clinical trials, many Seanconovox users suddenly became ruggedly handsome. The problem was that every one of them also developed an aversion to pants and an overpowering lust for squirrels. After a frightening melee in Hyde Park, the trials were shut down. But thanks for taking the time to reply, Liz!
And finally, let’s address my own ignorance in matters of pharmacology. Even I should have been aware of the extensive and thoroughly conclusive research proving that it’s chemically impossible for the Cubs to reach the World Series.
As for conditioning having no correlation with AMS, my own experience should have told me this. I have only had AMS symptoms twice in my life, once in my twenties and once in my late thirties. I was in great shape the second time, and couldn’t understand why it had hit me then. The randomness is also tough to fathom, since I went to exactly the same spot (Iceberg Lake) the next year, on the same timetable and in almost exactly the same shape, and I was fine. (I’m 57 now and have been near or above 14K many times in the last twenty years without any problems, though I’ve never been higher than the summit of Whitney.) So, thanks to all for the well-informed updates (gratis, no less!) on current thoughts and research on AMS. It’s appreciated!
Steve Porter
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Kicking Cairns
climber
Taos, NM
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May 15, 2008 - 03:06pm PT
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Ginko and Viagra show promise. Don't forget, Diamox will often improve sleep at altitude (probably due to it's affect on periodic breathing) and other sleep aids (save ambien) can potentiate AMS.
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apogee
climber
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May 15, 2008 - 03:40pm PT
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DR & matisse-
I'm very familiar with the historic body of research on AMS, starting with Charles Houston's early work through Hackett's research that began on Denali & Everest BC, and have attended a few presentations by Hackett as well. In the last 10 years or so, the best, most empirically tested information that has evolved seems to include:
*Edemic swelling is a common, perhaps normal response to altitude. It seems to be more pronounced in some people, and some individuals are simply more sensitive to it than others. (Hackett posited that those that do well at altitude simply have more room in their skulls- something that non-high-altitude climbers have known all along).
*Diamox (acetazolamide), once suggested to be used preventatively, is now more commonly suggested as needed, and at lower doses.
*Hackett once felt that guiding programs that regularly travel to high altitudes (i.e. Sobek-style treks, high-altitude climbing programs) would be strongly advised, even negligent, to not have Decadron (dexamethasone) available.
Of late, some limited studies have shown gingko and viagra having some benefits, but to my knowledge, the studies were very limited and specific in scope, and do not have clear answers as yet, aside from the humorous extrapolations one can get from them. Unfortunately, I don't have the sources of this information at hand- if either of you know of papers that described this testing, I'd be interested in reading them.
Many other drugs/substances have been experimented with over the years, from Rolaids to Lasix to ganja to nifedipine. Some, such as ganja and Rolaids, have been disproven or have nothing more than anecdotal 'research'; others, such as Lasix and nifedipine have gone in and out of style over the years. Nifedipine's calcium channel blocker affects were originally used at a time when it was believed that increased pulmonary arterial pressure was the chief mechanism for pulmonary edema, then as Hackett's research seemed to downplay this as the primary issue, and nifedipine became less prevalent. Of late I have noticed nifedipine being recommended again as one of the primary drugs for treatment (not prevention/acclimatization) of HAPE- do either of you know anything recent about this?
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tomtom
Social climber
Seattle, Wa
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May 15, 2008 - 05:02pm PT
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I'm pretty sensitive to altitude and usually start showing symptoms above 7000 ft. I get headaches on airplanes pressurized to 7500. I've turned around on climbs several times with headache, nausea, and excessive fatigue. Hydration and breathing are not issues.
Diamox does little for me (except make me pee), so I've been experimenting with Dexamethosone. On my last climb, I got up to 11,100 and felt pretty good for once.
I live at sea level in Seattle and have a number of beautiful 10k+ mountains in view that I want to climb. I can either sit on the couch eating cheetos watching TV, or pop a few pills and go climbing. I choose the latter.
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toejahm
Trad climber
Chatsworth, CA
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Topic Author's Reply - May 15, 2008 - 05:47pm PT
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Festus,
Interesting post!
Thanks for noting that my goal was to learn more about Diamox and the affects various climbers have experienced. As noted in the opening post, the suggestion to try Diamox was simply a possible solution to the delema of AMS and climbing trips where you have limited time to acclimatize.
And NO! I don't want to try a smaller river, this one seems just the right size.
Headintheclouds,
I'd be interested in the breathing techniques you mentioned. Anything I can read?
KR
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apogee
climber
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May 15, 2008 - 06:00pm PT
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KR-
One of the breathing techniques that has been recommended is 'power breathing'- this simply involves conscious, regular, somewhat forceful breathing patterns, along with pursed lips. Theoretically, it helped create something of a backpressure, supposedly forcing more O2 across the alveolar membrane and into the bloodstream.
Rainier Mountaineering used to teach this technique to their clients for many years, along with the rest-step, for the hoards of inexperienced climbers that they herded up Rainier. You always knew when an RMI guided group was near- they sound like a bunch of angry bulls coming your way.
I don't know that there is any clear science around the actual O2 saturation that occurs as a result of this technique (anybody know anything different?). At the very least, it makes one more conscious of breathing rates, which is probably a good thing.
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headintheclouds
climber
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May 15, 2008 - 06:10pm PT
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In general, breathing technique along the lines of that Apogee describes, traditionaly called Pressure Breathing.
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tomtom
Social climber
Seattle, Wa
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May 15, 2008 - 06:33pm PT
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I've a friend who is a pulmonary physician and studies altitude sickness and he believes that breathing is good, but "pressure" or "power" breathing is BS. The amount of backpressure produced is pretty trivial.
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headintheclouds
climber
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May 15, 2008 - 06:53pm PT
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Have never held that there is any validity to the stated physiology behind Pressure breathing, however, breathing in a more controled and focused manner has been successful for me.
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Ain't no flatlander
climber
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May 15, 2008 - 07:26pm PT
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Pressure breathing was developed for pilots at 40,000 feet on pure 02 and it also helps people with emphysema. But it does nothing for climbers. You can train the muscles used for inhalation and exhalation (with a special resistance gizmo) to increase breathing efficiency though it hasn't been proved to help at altitude yet. Hypoxic tents can work but most people say they are uncomfortable to sleep in and terrible for your sex life so that seems like a bad trade off (not to mention the $7,000 price tag).
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Dr. Rock
Ice climber
Castle Rock
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May 15, 2008 - 07:34pm PT
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at 12, i did A DEATH HIKE ITO T MEDOW, 5000 FEET , SICKER THAN A DOG, LAYED IN THE PINE NEEDLES, 2 HRA LATER, I AM ARNIE.
DEAL WITH IT NATURALLY.
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Doug Robinson
Trad climber
Santa Cruz
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May 15, 2008 - 07:48pm PT
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Warning, anecdotal information:
I use Pressure Breathing at times. If I'm pushing uphill at anerobic thresshold or slightly beyond, it definitely helps me -- I get significantly further than w/o it before tipping over into anerobic.
I purse my lips with enough pressure to essentially stop exhaling for just a few seconds. Best rhythm for me is this: repeat 2-4 times, then several deep breaths w/o pressure breathing, then back to another round of pressure breathing, etc. The presure breaths drive up my oxygen saturation, then the deep regular breaths blow off CO2. Seems to balance better in rapid cycle combination like that than either type of breathing by itself.
Technique matters. You gotta create enough pressure to bring the inside of your lungs to about sea level equivalent. So if 10,000 feet = about 2/3 atmospheric pressure = about 10 psi, then your goal is to briefly raise that to 15 psi (pounds per square inch) = sea level. So purse enough to feel that 50% pressure increase, but don't start bulging out your eyeballs.
Difference seems obvious to me in terms of mental and perceptual acuity. Brain is the O2 hog of your body, using 1/5 of every breath at rest, so it's not surprising to notice it respond when returning from slight hypoxia to fully oxygenated.
The few deep breaths are just as important. Shallow pressure breaths do not clear CO2 from deep in your lungs, but the deep breaths take care of that quickly. Important because your bloodstream measures not lack of O2 directly, but excess of CO2, and sets your breathing rate accordingly. If you don't blow off the CO2, you quickly feel out of breath and start gasping.
Maybe a more technical explanation than you want, but just give it a try -- your body is so sensitive to vital oxygen, it'll give almost instant feedback.
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Mtnmun
Trad climber
Top of the Mountain Mun
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May 15, 2008 - 08:18pm PT
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Question for you experts here:
I am fortunate enough to be able to run or scramble twice a week at 8500 to 9000 ft. for about two to three hours at a stretch and then return to 400 ft. My arobic heart rate is at top interval performance depending on the steepness of the trail.
For the summer season I will be in Idlewild most weeks climbing one day. 9000 to 10,000 ft?
I feel it getting easier some days and some days not. Will this keep me acclimated for higher mountains? I have had no altitude problems in the past. Or, what would be a better training cardio work out giving my proximity to the above referenced altitude?
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Zander
Trad climber
Berkeley
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May 16, 2008 - 12:18am PT
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I just skimmed this thread and there's more info than I could digest and I'm no expert but I do know that I'm really crappy at altitude. Yes, I usually only have the weekend so I can't move up slowly as I should. Though, when I have taken the time to acclimatize I've been OK. I retreated twice on the East arete of Mount Humphreys, mostly from being to slow but both times my head was pounding. I threw up too. This was pretty typical for me.
Then a friend of mine who guided for many years for Mountain Travel suggested I try one 250 mg diamox two days before the climb in the evening, then one the evening before and one each evening until the climb is over. My Doctor thought this sounded reasonable, about a third the dose he would suggest for someone flying to Tibet, so I gave it a go. For me it worked out. I still need to tough it out a bit but it helps a lot. I used it on an East Arete of Mt. Russell one day ascent, also on Mt. Whitney and Norman Clyde Peak weekend trips and it has been the difference. Check with your doc.
Zander
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apogee
climber
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May 16, 2008 - 01:20am PT
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Mtnmun-
Hate to say this, but periodic jaunts to altitude probably aren't going to do much of anything for enhancing the acclimatization process for you. The long term benefits of acclimatization (increased O2 carrying capacity of hemoglobin, pulmonary changes, cardiac changes, etc.) take weeks to develop, and only occur when one goes to altitude and STAYS at altitude. Much to one's chagrin, most of those acclimatization benefits are lost rather quickly once return to a lower altitude. (I seem to remember a study from years ago conducted on sherpas who had generations of living at high altitudes, who would move to a lower altitude for a relatively short period of time- perhaps a few weeks- then return to high altitudes- their sickness rate was about the same as anyone elses.)
What you will gain from your training routine is good aerobic fitness, which is always a good thing, and will help you to perform better, once acclimatized.
Aerobic fitness and acclimatization are commonly lumped together, and while they hold some similarities, and are certainly related to one's performance at altitude, they are different physiologic processes.
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Jello
Social climber
No Ut
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May 16, 2008 - 02:41am PT
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Tried diamox once at about 23,000' and had one of the worst nights of my life. Had all the side effects mentioned earlier--multiplied ten-fold--but with none of the purported benefits. Never used it again.
-JelloAndDiamoxDon'tMixWell
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matisse
climber
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May 16, 2008 - 03:19pm PT
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wow, where to start. I'll try to chip away at all of this if you guys are interested over the next few days. I have to do it in bits and pieces because I'm on the spring scientific meeting circuit, and I'm punting an NIH grant out the door in the next 2 weeks. (I'm just buttering y'all up, because this is what I do for a living and we are always looking for research subjects particularly those of you who ALWAYS get AMS and also those of you who have had HAPE-even once, whether or not you get AMS).
You can access virtually all the literature through pubmed if you want to read the original work. Most if not all journals have open content one year after publication and a lot have all their work in digital form.
Lets start with Judes question about intermittent exposure to hypoxia and whether or not that will help him for higher peaks. There are several parts to acclimatization but the type of acclimatization that most climbers will use when they climb a peak is the short term ventilatory (breathing) acclimatization.
The breathing response of the body to hypoxia is called the hypoxic ventilatory response (HVR). It works like this: you get exposed to hypoxia, receptors in your neck (carotid chemoreceptors) sense the lowered oxygen and tell you to breathe more so you increase both the rate of breathing and the depth of breathing. Besides increasing the oxygen in your blood stream above what it would have been if you kept you breathing at normal levels, this also acts to lower the CO2 in your blood and also to make you blood more alkaline. This then tells these rapidly acting chemoreceptors that you are breathing too much and inhibits the response that the lowered oxygen has started. The lowered CO2 also affects receptors in the brain (central chemoreceptors) which further inhibits the response (and they don't response to low oxygen only CO2/pH. Over a few days the kidneys act to normalize the pH effects and the breathing increases further, the CO2 gets lower and the oxygen gets higher. This whole process takes about 5 days.
The sensitivity of this response-how much you breathe in response to a given level of hypoxia varies between people and with acclimatization (generally the more sensitive your response is, the less AMS you will experience). The neck receptors become more sensitive when they are exposed to hypoxia, both after a few days of continuous exposure and more recent studies have shown even after intermittent exposure. We don't know how long this increased sensitivity lasts.
here are a few citations you can find in pubmed.
Koehle M, Sheel W, Milsom W, McKenzie D.
The effect of two different intermittent hypoxia protocols on ventilatory
responses to hypoxia and carbon dioxide at rest.
Adv Exp Med Biol. 2008;605:218-23.
PMID: 18085275 [PubMed - indexed for MEDLINE]
Lusina SJ, Kennedy PM, Inglis JT, McKenzie DC, Ayas NT, Sheel AW.
Long-term intermittent hypoxia increases sympathetic activity and chemosensitivity during acute hypoxia in humans.
J Physiol. 2006 Sep 15;575(Pt 3):961-70. Epub 2006 Jun 29.
PMID: 16809359 [PubMed - indexed for MEDLINE]
Townsend NE, Gore CJ, Hahn AG, McKenna MJ, Aughey RJ, Clark SA, Kinsman T,
Hawley JA, Chow CM.
Living high-training low increases hypoxic ventilatory response of well-trained
endurance athletes.
J Appl Physiol. 2002 Oct;93(4):1498-505.
PMID: 12235052 [PubMed - indexed for MEDLINE]
Katayama K, Sato Y, Morotome Y, Shima N, Ishida K, Mori S, Miyamura M.
Intermittent hypoxia increases ventilation and Sa(O2) during hypoxic exercise and
hypoxic chemosensitivity.
J Appl Physiol. 2001 Apr;90(4):1431-40.
PMID: 11247944 [PubMed - indexed for MEDLINE]
Garcia N, Hopkins SR, Powell FL.
Effects of intermittent hypoxia on the isocapnic hypoxic ventilatory response and
erythropoiesis in humans.
Respir Physiol. 2000 Oct;123(1-2):39-49.
PMID: 10996186 [PubMed - indexed for MEDLINE]
So the answer is yes it will
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ontos
Boulder climber
Washington DC
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May 16, 2008 - 04:25pm PT
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I also have occasionally had trouble at altitude. This has always happened visiting areas around La Paz in Bolivia. Usually I have a hard time on the second and third day at 13000ft+ is really tough. I also have trouble eating sufficiently. The locals swear by coca de mate which is a tea made from the leaves of the coca plant (yes that coca plant). I've never visited La Paz and not consumed loads of the tea so cannot say whether it helps or not; my guess is that it helps with hydration and maybe has some mildly beneficial stimulant effects but not much else. Just wondering if anyone has any data on this beverage.
Never tried Diamox, but may on my next trip.
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