Sports Medicine — Altitude Problems vs Water Sickness

Post by blogger | August 22, 2018      

Fitness and health for ski mountaineering.

Skimo fitness and health.

Ramping up to renew our first aid certifications has us learning about altitude disorders, such as what you might encounter at a high mountain hut in Colorado. I’m binge watching every single E.R. and all 176 episodes of House M.D., but that’s not quite doing the trick. Getting current information from live lectures and careful internet study is much more helpful.

To that end, Lisa and I attended a pair of lectures about swollen brains: how to prevent, evaluate and treat. I know, I know, you’re asking me if we’ve found some new exotic treatment for my swollen ego. Sorry, the magic hubris bullet will be covered in another blog post. Instead, we got an interesting take from the famed Dr. Peter Hackett and our Aspen ER doc Scott Gallagher, also an expert on altitude and backcountry related medical issues.

While I found Hackett’s lecture amusing and educational, where the gist of the session resided (for me) was in Gallagher’s talk comparing hyponatremia to the cerebral edema caused by poor adaptation to high altitudes. The altitude version is known as HACE, while the brain swelling brought on by exercises and over-hydration is known as EAH, exercise-associated hyponatremia.

Hyponatremia is an imbalance of the body’s normal blood sodium levels. Minor occurrences can cause symptoms such as dizziness, while more extreme cases lead to death due to the brain swelling too large for the skull cavity and herniating through the opening at the bottom of the skull.

“Sub-acute” hyponatremia is somewhat common with the elderly, and during hospitalization for anyone. If the sodium fluctuations happen slowly it’s not usually lethal (though still at concern.) On the other hand, slugging down too much water can bring acute hyponatremia in mere hours, especially if you’re exercising (due to physical effort messing with a hormone that keeps sodium levels balanced.) Left untreated, or improperly treated, the condition kills. More, in my opinion, since moderate hyponatremia can cause dizziness and disorientation, un-diagnosed instances have probably resulted in quite a few accidents over the years.

For mountaineers, the problematic part of this is the old song: “You’ve got to stay hydrated, more hydration is the solution to altitude problems. Drink water. Keep drinking.” Turns out this is wrong. So wrong. “Drink when you’re thirsty, don’t over-hydrate” is now the consensus in sports medicine. That includes altitude. In fact, Hackett said that studies show over-hydration can lead to exacerbated altitude illness symptoms!

IMPORTANT: Electrolyte sports drinks will NOT prevent hyponatremia. None have the necessary (or desirable for normal use) sodium concentration. Again, drinking only when you’re thirsty, and not over-hydrating are the key factors.

And how shall us first-aiders tell the difference between altitude induced brain swelling and that of hyponatremia? Doing so is nearly impossible without specialized equipment. Testing blood for sodium levels is the key, but you’ve can’t do that without a portable blood analyzer such as the i-Stat — bulky, costing anywhere from $300 to $10,000. The takehome from both Glagher and Hackett was that patient history is key. If the subject has ascended quickly to the type of altitudes that induce illness, and has not been pounding water, that’s one thing. If altitude isn’t as big a factor, but you find out the person has spent a day in heavy exercise while drinking liter after liter after liter of water due to the discredited myths of athletics, consider EAH.

Either condition is of course serious. According to Hackett, if any change in cognition is present, immediate evacuation is key. With the caveat that common (and wrong) procedure for emergency med techs is to dump IV “normal” saline solution, but that doing so can kill a hyponatremia victim (has probably happened more than once) and doesn’t help someone with HACE. In the case of hyponatremia, the field treatment can be simply waiting for the body to excrete excess water, or perhaps an oral high-sodium solution such as a couple of bullion cubes dissolved in a small amount of water. If the equipment and materials are available, and blood sodium imbalance has been verified, treatment may include injecting high sodium concentration saline, or injecting the same sodium bicarbonate “amp” used by EMTs and doctors to treat cardiac arrest.

A few other things: In terms of social contract, it’s a good idea for groups involved in extreme mountain sports to monitor each other’s actions, such as hydration, calories, and so forth. If someone has a medical problem, patient history is key and sometimes the victim is too out of it to relate any meaningful information; companions can fill in the blanks. In terms of hyponatremia specifically, I’m told that most ambulance crews as well as medical helicopter services carry the blood analysis device. If hyponatremia is suspected, it’s not a bad idea to remind the EMTs to use their blood analyzer and pay attention to the sodium level number, as well as hesitating with the customary saline dump since starting a possibly contraindicated IV is nearly a reflex procedure for these guys. Give normal saline to a hyponatremia patient, you can kill them.

Web MD summary:

And more here:

Interesting reading from Hackett:



10 Responses to “Sports Medicine — Altitude Problems vs Water Sickness”

  1. aemono August 24th, 2018 5:44 pm

    No comments? Real innarestin’..i’ve been pushing this for years, drink when thirsty..and don’t over-drink. Wildsnow readers immune to the hydration-mania of recent times?

  2. Jim Milstein August 24th, 2018 9:34 pm


    I never drank the hyper-hydration Kool Aid. I seldom drink, or want to drink, more than a liter of water on a day outing, but usually take more along, just in case. Not dead yet!

  3. sedgesprite August 25th, 2018 1:15 am

    I’m trying to put the pieces together here. Hackett does say that athletes can weigh themselves before and after exercise to arrive at reasonable fluid intake. For heavy sweaters this adds up to a lot of water- beyond the thirst signals which for some of us are suppressed for real or imagined reasons. Some reports also recommend gulps rather than sips to signal the stomach to begin absorbing liquid. Our gang ‘pre-lubes’ with up to a liter before activities, long enough so that sloshing isn’t part of the ritual. Oddly, at dawn patrol, the water seems as effective as coffee at increasing alertness, but there is no dawn patrol without coffee, so part of it may be an anticipatory set. Is the ‘clear and copious’ urine standard now defunct? I don’t have a dog in the fight, just want to ski more.

  4. Lou Dawson 2 August 25th, 2018 5:08 am

    Sedg, if I recall correctly, at our seminar the doctors said you want to end an exercise effort at somewhat lower weight than when you began, but of course not to the point of dangerous dehydration. They said that “reasonable fluid intake” and “only drinking when thirsty” will mean the athlete will have a modicum of weight loss at the end of an extended effort. The idea here, and I’ve got a lot of experience with hyponatremia (family health stuff), is that you replace the water you use, avoiding the consumption of excess. The athletes who’ve been dying from water sickness have often been drinking somewhat ridiculous amounts.

    It should be repeated that electrolyte drinks do not help, worse, they can psychologically mask the need to be careful. As in “my Gatorade has sodium, so I’ll drink gallons, what me worry?”

  5. JCoates August 25th, 2018 1:41 pm

    I think we might be complicating this more than it needs to be. Even though hyponatremia and altitude illness are pretty complicated physiologically, Dr. Hackett did a great job simplifying recommendations for hydrating at altitude:

    “Staying hydrated is important at altitude. Symptoms of dehydration are similar to AMS. In reality you only need an additional liter to a liter and a half of water at altitude. Too much water is harmful and can dilute your body’s sodium level (hyponatremia) causing weakness, confusion, seizures, and coma. A good rule of thumb to assess for hydration is to check your urine. Clear urine indicates adequate hydration, dark urine suggest dehydration and the need to drink more water.”

    If you don’t know how much water you normally drink during endurance events, you don’t have any business doing those events for the first time at altitude.

    In my experience, drinking and eating are NOT easy at altitude if you’re not acclimated. Altitude wreaks havoc on appetite (air expansion in the stomach and intestines) and overall energy (overall hypoxia) so people tend to forgo drinking and eating like they might down low. I would bet a hefty chunk of change that dehydration caused more failures in the big mountains than hyponatremia. Because of this, the general thought has always been to recommend eating and drinking as much as you can just to keep up with your normal demands. But of course there were probably a few inexperienced individuals who figured they could ward off AMS by doubling their water intake–even though they wouldn’t try something so silly at their home elevation.

    I wasn’t at the conference, but I suspect the docs’ advise was probably closer to: “of course you should hydrate–but only a little more than you normally would.”

  6. Lou Dawson 2 August 25th, 2018 2:15 pm

    Good stuff J, thanks! Lou

  7. mtndoc August 25th, 2018 10:28 pm

    Lou, I think you reviewed the info by both docs very well. Drink when thirsty and eat some high salt snacks. Pringles, anyone?

  8. brian harder August 28th, 2018 10:42 am

    Good stuff. The people who really need to take heed are the undereducated mountain guides who continue to push their clients to drink, drink, drink. The myth that being hydrated will help stave off AMS is ingrained into that culture. I’ve witnessed it first hand as a guide in AK, Nepal and South America. All you create at the very least is sleep disruption having to pee during the night after pounding 4 cups of tea before bed and at worst all the bad shit you mention here.

  9. Slim August 31st, 2018 7:20 am

    RE: clear and copious clear urine:

    I distinctly reading somewhere recently that athletes should NOT use this standard, since a natural physiological response to ex cerci seems is for the body to reduce/concentrate urine output.

    In other words, if you are exercising hard, and your urine is copious and clear, it’s because your body is dumping excess fluid.

    I’ll see if I can find any reference after, but for now this will have to do.

  10. Lou Dawson 2 August 31st, 2018 11:18 am

    Slim, indeed, peeing “gin clear” is not a good standard unless combined with an overall sense of how much hydration is occurring. In other words, it’s doesn’t take much extra water to make the “gin clear” so if consumption hasn’t been excessive, then no harm, no foul. On the other side of the equation, it’s my understanding that in extended endurance situations, such as a Denali expedition, highly concentrated urine is indeed an indicator of inadequate fluid intake. The goal is a happy medium.

    I know a person with chronic hyponatremia (genetics and age), when it goes over the line they have to meter their water intake. Doing so isn’t actually all that tough, they just start the day with a couple of clear plastic water bottles containing the 24 hour allotment specified by doctor, and start digging in, until it’s all gone. Interesting.


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