allitude sickness

I read an article on drinking water at altitude, written by some folks at a adventure guide company who lead Everest and other 8000m climbs. They claimed that water consumption has shown them that almost any condition caused by altitude can be rectified by drinking water. I remember thinking it wasn't very scientific but that they made a good case.

Edit- found the link to said article: http://www.mounteverest.net/expguide/cure.htm

JJ-

The doctors who told you to take iron was making a conceptual error. Yes, people who live at high altitude do get thicker blood, but that takes a long time. Certainly longer than a couple of weeks, IIRC.

Now, speaking as a specialist who has been out of medical school for 7 years and has forgotten a lot of this useless stuff…

Acetazolamide (Diamox) has been shown to speed altitude acclimatization in that you will achieve a higher blood oxygen level a little sooner if you take it. This is not primarily due to it's diuretic effect though, as Mark was alluding to. (Though, of course, being a diuretic conceivably helps with HAPE or HACE. But there are much better things to do for those, like GO DOWN THE MOUNTAIN.)

Acetazolamide somehow speeds the adjustment of the threshold for respiratory stimulation due to blood PaCO2.

For you laymen, here's a thumbnail sketch:
One of your body's stronger stimuli to breath is a high blood CO2. The CO2 level in your blood is normally essentially independent of the O2 level in your blood. But here's the thing- the faster you breath the more CO2 you will off-gas and your blood CO2 level will go down! (Well, technically, it isn't how fast you breath- it's your minute ventilation, which is breathing rate x breath volume. Sort of.) When you go to altitude the CO2 in your blood is essentially stable so you still breath at a low rate just like you did at sea level, but since the air is thinner you are getting less oxygen. Thus your blood oxygen goes down, and you feel weak and tired, and this somehow leads to AMS, HAPE, and HACE. You body will eventually realize this and adjust the threshold for respiratory stimulation to a lower CO2 level, so that you will breath faster to get more oxygen even when your blood CO2 is low. Acetazolamide somehow speeds this adjustment. Typically the dose is 125mg at the start of the elevation gain, and 125mg after 12 hours, IIRC, but I'm not sure. EDITED– UpToDate says 250mg prophylactically every 12 hours starting 2 or 3 days before the trip for rapid ascents to over 7000-8000 feet and stopping once you've been at goal altitude for a day. It contradicts itself on effectiveness after symptoms have already appeared.

So, I THINK acetazolamide makes you feel better and perform a little better due to higher blood O2, and i think it reduces the risk of AMS, but I don't think it has been proven to reduce HAPE or HACE. I'll have to check when I get home. I do recall that it has been proven to greatly improve sleep quality at altitude, as Mark alluded to. (Bad sleep is caused by Periodic Breathing of Altitude which, believe it or not, is a type of Cheyne-Stokes respiration.)

This is all similar to what we think causes shallow-water blackout, by the way: Typically, someone breaths fast and deep for a little while in an attempt to oxygenate their blood so that they can stay underwater longer. In reality, they have only driven their blood CO2 level down. (For all practical purposes you can't get blood O2 above 100% hemoglobin saturation. There is a small amount of O2 dissolved directly in blood plasma, but it is a trivial amount.) Due to the low blood CO2 they don't feel an urge to breath! Eventually, if the O2 runs out before the CO2 climbs high enough to drive a respiratory urge, they pass out and drown. This is why experts advise not taking more than three deep breaths before free-diving.

By the way, you loose you acclimatization VERY fast. There have been people who live high in the Rockies who have gone down to town for only 2-3 days, then gotten AMS upon returning home. Well documented.

The nice thing is that you shouldn't have much trouble talking your doctor into prescribing you some acetazolamide if you tell him you're going mountain climbing (or whatever). It's pretty benign, but it counts as a sulfa drug, so if you have an allergy to sulfa you can't use it, and it plays hell with blood sugars in diabetics. You might have to give doc some time to read up on it, though, before he'll write you the script. On the other hand talking him into giving you some dexamethasone will be difficult, to say the least, even though the studies show that it is a better prophylactic than acetazolamide. You'd better provide PROOF of your upcoming Everest attempt…

And, dammit, it does ruin the taste of ANY carbonated beverage. I think it inhibits carbonic anhydrase, or something, so things tend to taste more acidic and sour.

Reference: Auerbach's "Wilderness Medicine," currently in it's fifth edition, though mine is older. This is a $160 textbook that isn't of much use to laypeople, so though it does sound interesting don't rush out and buy it. It's very technical.

Also, yes, Advil and other NSAIDS (like Tylenol, Motrin, etc.) act as "blood thinners", but that is a lay misnomer. These drugs slightly inhibit clotting, and this is what is meant by "blood thinner." They don't have an appreciable effect on the number of blood cells per unit volume of blood (i.e. hematocrit or hemoglobin levels). Confusing terms.

nm

I think the most important part of this thread is not what medicine you should take and what medicine works the best or even why any medicine works at all. The message I hope everyone gets is that if you are having symptoms you should descend. You shouldn't stay at the same altitude, you should descend.

Stop taking drugs like, pain medication and all that other junk that is performance enhancing like the altitude medications. Taking drugs to perform better is cheating. If there were a machine to get a person into shape I bet all of you "drug takers" would be willing to stop walking and instead use the machine to get into great shape. Pill popping is not the answer for everything.

Hi Dean

You know, that is the simplest and clearest explanation of these things I have ever read (and I have read a bit). Thank you!

With your permission I might even include much of your posting (eventually) in the bushwalking FAQ I maintain, if you don't mind?
http://www.bushwalking.org.au/FAQ/

Cheers
Roger Caffin (PhD)

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If you argue your point long enough, then all we should be able to do is drink water and eat just enough calories to survive, and all have the same gear (because isn't going ultralight also cheating?). Maybe we should just hike naked with a canteen and a knife.

"Eventually, if the O2 runs out before the CO2 climbs high enough to drive a respiratory urge, they pass out and drown. This is why experts advise not taking more than three deep breaths before free-diving."

Holy crap, good to know! I've done this before (taken plenty of breaths before skin-diving) and have never read this warning before. Luckily I haven't done it often or I might have found out the hard way.

"Please tell me what else I am supposed to do, or not do, in a judgmental and closed-minded fashion, please."

He just did, Dave. :)

"Maybe we should just hike naked with a canteen and a knife."

That's cheating, too, Zack. Camel up and learn how to knap flint.

Roger,

Go for it!

Timothy,

Get off your high horse. No one is talking about taking drugs for performance enhancement- after all, hiking is rarely a competetive sport. Well, directly competetive, anyway. We're talking about treating or preventing illness. If you're so drug averse I'll discuss crystal therapy with you the next time you get an infection. :)

Unfortunately many people can't afford to take the time for the 1 day per 1000-2000 feet acclimatization model. Acetazolamide has a great safety record for this use (though not a perfect one, of course). If your doctor says it's safe then I have no problem with people using acetazolamide prophylactically when they expect to make sudden ascents to over 8000 feet. That's an important point: if your doctor says it's safe. There is a reason acetazolamide is a prescription drug.

Incidentally, I did check my "Wilderness Medicine" book. Acetazolamide is a carbonic anhydrase inhibitor- so my memory didn't fail me. In particular it also inhibits the carbonic anhydrase on your tongue surface, which is why all carbonated beverages take like dogsh*t while you're on it- the dissolved carbonation doesn't get instantaneously neutralized as it should.

The book also says that acetazolamide does help alleviate mild AMS symptoms after they appear, but you have to take it very early. Taking it after more than a few hours of symptoms does not seem to help much, so it is much more useful as a prophylactic. My lawyer's angina dictates that reemphasize that if you have any symptoms more severe than a bad hangover then you do not have AMS. You probably have HAPE or HACE, and you need to get down the mountain quickly, before you deteriorate so far that your buddies have to carry you.

What the heck, I'll digress…

Early symptoms of HAPE are easy to dismiss- fatigue, increased recovery time, shortness of breath with exertion, etc. Tachycardia (pulse>100/minute) and tachypnea (breaths >30/minute) are common, but unfortunately aren't highly specific. AMS-type symptoms occur, too- headache, poor appetite, nausea, etc. An unexplained dry cough is a more specific sign, as is shortness of breath at rest. Shortness of breath when laying on your back is also pretty specific. If lips or nailbeds turn blue or if you hear gurgling sounds during breathing, well, you have a diagnosis. HAPE. Pink or frothy sputum is a very LATE sign- you have missed the boat. The patient will not be ambulatory much longer, so start planning to carry him down.

HACE should terrify high-altitude solo hikers, because one sign is poor judgement. As with hypothermia, your judgement can be so poor that you are unable to diagnose yourself, and you die. Early signs are an unsteady gait, particularly requiring an unusually wide stance or short choppy steps. Also confusion, drowsiness, and poor motivation. AMS symptoms are also common- headache, poor appetite, nausea. Vomiting is common, but not universal. As you might imagine hallucination, seizures, paralysis, and coma are LATE signs- again, you have really missed the boat. Contact next-of-kin for disposition of remains unless you can get them down very fast.

I have not found any data on whether or not acetazolamide prophylaxis reduces the incidence of HAPE or HACE. I suspect that IF there is such an an effect that it is small, and thus it would be difficult to design a double-blind randomized controlled trial that would be sufficiently powerful to prove it. Certainly, acetazolamide is NOT an appropriate treatment, except for it's diuretic effect in combination with descent.

Zack,

Like Bear Grylls? Well, he usually takes a metal cup, too. And Motel 8, of course… :)

Can you tell me the side effects of these altitude drugs. What happens when some inexperienced hikers decides to take a couple of these pills with him hiking and then figures out that he is having an allergic reaction to the drug after going 20 miles in to the wilderness. Drugs can kill. The argument about not having enough time to become acclimatized is strong, however what are the long term risk factors of taking this drug. I suggest that for all of you drug popping individuals taking altitude medication that you do a cost benefit analysis about taking these drugs. For those of you who climbed a fourteen’er using these drugs, it wasn’t you climbing it was the drugs climbing for you.

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I'm very pleased with the results I get from acetazolamide.

"For those of you who climbed a fourteen’er using these drugs, it wasn’t you climbing it was the drugs climbing for you."

Timothy,

Is caffein on your list of banned substances? All sorts of side effects associated with it; And without it. How about alcohol? Where do YOU draw the line?

Until backpackers have a governing body and anti-doping association with a full list of banned substances, who are we to say what can and can't be taken by hikers? And why spend so much energy putting others accomplishments down–does that makes your accomplishments seem greater? If you really think the way you do, then you should never take medicine–because then it wasn't you who beat the sickness, it was the meds. And that's cheating.

I've always used Ibuprofen for allitude sickness. Some say it gives you an upset stomach, but not so unless you take it on an empty stomach. I guess that might not apply to some, but thats what I've heard.

hope that helps

I don't know if somebody already mentioned this, but I've had great results with gingko biloba. If you search the internet, you may be able to find an article about a study done with gingko and mountaineers–from my faulty memory, I think that with the placebo group, roughly 70% had altitude sickness, but with the gingko group, roughly 15% did. I think it may increase blood flow to the brain (which is also why it has been touted as a memory aid).

Sorry for my earlier posts–I normally don't respond to troll's comments, but I can't stand it when people put down others accomplishments. My girlfriend and I call it "old man syndrome", and we've experienced a fair amount of it on our thru-hikes.

Timothy,

Unfortunately, NOT taking drugs can kill as well, so your insistance that "drugs can kill" is a little ridiculous. But, to be honest, we're talking about AMS here, not HAPE or HACE.

Really, Timothy, get a grip. Acetazolamide is not a "performance enhancing drug" in this context or any other. Your insistance that it is is misguided. Rather, it is prophylaxis against an illness, if you cannot expend a week just getting acclimatized before you start your hike. Yes, it will lead to faster acclimatization and thus a recovery of blood O2 levels sooner, thus avoiding AMS. But it is NOT an equivalent to blood doping, or whatever you're thinking of. I'm sure it is on the IOC's list of banned substances, but so so is pseudoephedrine! All acetazolamide does is speed up your natural acclimatization process. Thus THIS quote is laughable, too:

"For those of you who climbed a fourteen’er using these drugs, it wasn’t you climbing it was the drugs climbing for you."

If you had spent the time to acclimatize, would it have the time climbing for them? :)

I'm talking about preventing or treating a disease. AMS, I will remind you, is "Acute Mountain SICKNESS." If you want to embrace your AMS then, brother, all the more power to you. Snuggle up with it.

If you had paid attention you would have noticed that the prophylaxis starts 2-3 days BEFORE you go on your hike. Thus you are unlikely to anaphylact when you are all alone in the wilderness, should you choose to hike solo. (And that's why I warned about sulfa allergies.) If someone wants to use this drug to prevent AMS he needs to talk to his doctor about it first.

Are there risks and side effects? Of course! Everything in life is a trade-off, Timothy. If you don't drink enough the diuretic effect will lead to dehydration, to name an obvious one. If you look up the warning label it will list every bad thing that ever happened to someone who took the drug during the trials. That's why EVERY drug lists headache and nausea as a possible side-effect, by the way. But, heck, eating persimmons is risky (bezoars)! Or peas (lathyrism)! Or licorice (hypokalemia leading to ventricular tachycardia)! Or water (hyponatremia)!

All of that said, at it's root, I personally agree with your hesitancy to answer every problem with a pill. On the other hand, some problems respond VERY WELL to a pill. This is one of them. If someone wants to use this drug to prevent AMS he needs to talk to his doctor about it first. Do I think that EVRYONE who is going hiking at higher than 7,000 feet should take acetazolamide? Of course not! But, as a for-instance, if you've had AMS before then you are at higher risk, and you might consider it, to avoid a few very miserable days stolen from your valuable vacation time. As another for-instance,if some flatlander who has never been higher than the nearest overpass was planning to bag a fourteener that was going to take more than a couple of days, they might consider it, as well.

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"well said. it's nice to have an actual doctor around."

Hear, hear!

FWIW…

in addition to the prescription meds., recently Backpacker Mag. also suggested aspirin.

"it's nice to have an actual doctor around."

With the caveat that I'm not an altitude medicine specialist… I'm going by what I remember from school and a very brief literature search.

I also sort of owe Timothy an apology. I got a little heated because I thought that he was denigrating anyone who decided to take medications, even if they were sick. (There are people like that out there.) I now realize that an innacurate statement of mine might have led him to believe that acetazolamide was "performance enhancing"- where I said "I THINK acetazolamide… makes you perform a little better." That was an amazingly poor choice of words on my part. I meant only to imply that, since it leads to faster acclimatization, you would be performing at your OWN peak efficiency sooner than you would if you acclimatized by spending a day to climb each 1000 feet. (Obviously.)

I think I agreed with 100% of what Dean wrote, based on some limited experience with Diamox. First of all, Diamox is a sulfa drug, as he stated. If you are allergic to one sulfa drug, you are likely to be allergic to all of them. That sort of allergy is important to know before you ever leave home or leave the vicinity of an emergency room. So, explain your concern to your physician.

In my opinion, awfully few southbound JMT hikers need to fool around with it. Northbound JMT hikers get hit with more altitude suddenly, but a day or two of proper preparation at moderate altitude will minimize the problem for most. If you intended to hike up Whitney and sleep on top for a night or two, you might have much more of an altitude problem.

OTOH, I know a few otherwise-healthy individuals who know that they have a problem when they go over 11,000 feet, so they have found from past experience exactly how much Diamox to take to prevent symptoms. They use Diamox about like I use a daily multivitamin pill. I think some of the medical literature suggests that a smaller daily dose (125mg) is just as effective as the larger daily dose (250mg) and there are reduced side effects. I can't cite the literature right now without raiding Dean's library.

Diamox does not prevent high altitude illness, but it seems to afford an extra measure of prevention. In other words, it seems to force your body to adapt faster and more completely to altitude than it might have otherwise.

Some people adapt quickly to altitude, some adapt slowly, and some don't adapt well at all. If you are in the first group, you probably don't need to use it. If you are in the other two groups, it might be worth having that discussion with your physician. If you are unfit, then this is not going to help much.

When I asked for my first Diamox prescription (15 years ago), my physician started to give me a hard time. But after he had looked it up, about ten minutes later I got my prescription.

For 99% of hikers, you don't need to fool around with Diamox unless you are going very high and/or going up very rapidly. As an example, a small expedition of us climbed Aconcagua (almost 23,000') and I think we summitted on the eighth day, so the majority of us were taking either 125mg or 250mg daily. After the trip, I tried to correlate the statistics. Among those who successfully summitted, by far the majority were using Diamox. Among those who were unsuccessful, a slight majority were not using it. One person not using it collapsed near the summit with suspected HACE and had to be escorted down. That is not a large statistical population, but it shows a trend. I stopped using it on summit day and the side effects went away after a few days.

On a Nepal trip to EBC, we were going a bit above 18,000', so almost everybody got their prescription Diamox and started taking it when we first left Kathmandu. I believe I was the only exception. I carried it but never used any.

On a Kilimanjaro trip, we were going to 19,340' and would be camping in the crater at 18,800', so almost everybody got Diamox and started taking it. I believe I was the only exception among the trekkers. I had a lot of it on hand, since I was not using mine, and the local trip leader persuaded me to give it to him so that he could distribute it to his local porters who were sick as dogs! Frankly, I felt like they were using it all wrong. I had been recording my vital signs all the way along, and my body had never shown the first sign of any altitude stress, which is why I never used any on the Kili trip.

So, for the southbound JMT hike, I would not bother with Diamox unless I was really expecting a problem. There are several small non-drug things that you can do that will probably get better results and have no side effects like tingling in the extremities or major taste changes for carbonated beverages.
–B.G.–