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Interesting article on HAPE risk factor

Posted: Sun Apr 22, 2007 3:54 pm
by gdurkee
Just ran across this article in the April 4 Science News on a possible relationship between both sleep apnea and, perhaps, High Altitude Pulmonary Edema (HAPE). If you or someone you know is susceptible to HAPE, it looks like someone has a trial going to see if correcting an otherwise minor congenital heart problem solves HAPE or even sleep apnea problems.

I posted it at: ... a-HAPE.pdf

I know two otherwise healthy people who commonly show signs of either Acute Mountain Sickness or, even, HAPE as low as 8,000 feet.


Posted: Sun Apr 22, 2007 4:46 pm
by mountaineer
Any connection between insomnia and HACE?

I don't have any experience with HAPE but had an epic with HACE on White Mountain. I had been over 14k a couple of times, over 13k numerous times, and over 12k more times than I could count and never had altitude sickness of any type. Then, about 5 years ago, I became violently ill with HACE symptoms at only 13k.

Six months later, the same thing happened on Shasta at the same altitude. I guess my days of going over 13k are finished.

Posted: Mon Apr 23, 2007 12:16 am
by Trekker
Thanks for posting the article; very interesting information.

Sleep Apnea is typically a condition associated with overweight or obese individuals. The Soft Palate, located in the throat region, will typically relax during sleep. Weight gain can lead to an increase in the mass of the soft palate, causing it to collapse and block the wind tunnel. This leads to a halt in breathing until the palate is forcefully cleared. Correcting the problem will lead to less of a risk of rapid desaturation of the blood of oxygen. This by and of itself will not correct the sleep apnea, but will lessen the risks associated with the compounding of the oxygen desaturation by desaturated blood from the right side of the heart flowing through the PFO and mixing with the already partially oxygenated blood in the left. And as those who are involved in climbing and peakbagging rarely tend to be obese, you will usually not see sleep apnea in these individuals. However, the existence of the PFO by itself may lead to sleep apnea-like symptoms. Since oxygen desaturation during sleep prevents maintenance of deep stage, or delta wave sleep, it is conceivable that this condition could lead to frequent awakenings or very light sleep at altitude for individuals who have this condition.

Sleep apnea, HACE etc.

Posted: Wed Apr 25, 2007 10:55 pm
by gdurkee

Boy, that's bad luck. HACE is even more rare than HAPE. I'm less familiar with the causes of HACE, though. Everyone talks of AMS, HAPE and HACE as being on a continuum of symptoms of poor acclimatization, but I'm not clear on what, exactly, is going on other than low O2 saturation. It would be interesting if there's a relationship with the PFO. I know 2 people who start showing signs of HACE at 8,000!

A guy I used to do snow surveys with was definitely in either sleep apnea or cheynes-stokes -- and maybe they're related (??). Anyway, asleep, he'd just stop breathing for 10 to 15 seconds, then snort like a water buffalo and start again. A bit nerve wracking in a small cabin with any medical about 8 hours away. I sent the article to him. (He's also a big guy which, as Trekker points out, is a risk factor). Maybe he knows why you get Cheynes-Stokes at altitude??

Anyway, none of these are things to fool around with at altitude. Good thing there's a lot of fun stuff to do below 13,000... .


Posted: Thu Apr 26, 2007 8:51 pm
by Shawn
"he'd just stop breathing for 10 to 15 seconds, then snort like a water buffalo and start again."

I know that's a potentially serious situation, but that wording sure gave me a laugh. :D

AMS strikes me in a very unpredictable manner. Even when I do all of the same things (hydration, etc.) sometimes it'll hit me at low elevations and most of the time it doesn't affect me at all. I just thru in the towel and hope for the best when making plans.

Posted: Thu Apr 26, 2007 10:06 pm
by Snow Nymph
SnowDude has had HAPE 4 times. He sent in an application for one of the studies, but they didn't want him for some reason.

The first time (~10 years before I met him) he was helo'd out from Guitar Lake. George was the ranger that made the call. SnowDude was reading "the Last Season" and saw George's photo, and said "this is the guy who called for the helicopter". I told him George was on this board. Small world!

anyway, the next 3 times we were on multi-day backpacks. All 3 times he got rales on the third morning.

The first time (1998?) I didn't know what it was. We were at Second Recess and continued over Gabbott Pass down to Italy Lake and over Italy Pass. It rained for 5 days, and on the 6th day the sun came out and skys were blue and he felt so much better hiking out from Honeymoon Lake.

The next time was at Cottonwood Lakes (June 2000). He was sluggish as we dayclimbed Langley from Muir Lake. He kept saying he was ok, but it wasn't like him to lag so far behind. Near the summit I knew something was wrong, but he insisted on going since we were so close to the summit. On the way back, on Old Army Pass, he was on his back. It started raining, thunder, lightning. We got headed down as fast as he could move, which wasn't fast. Hail collected on the packs. We got back to camp and he couldn't answer simple questions, like 'do you want me to turn the stove off?' He couldn't eat anything and went to bed. The next morning he had rales, and could hardly tie his boots or comb his hair. We descended, and I took a lot of the weight from his pack. (the days when our tent weight 6 lbs!!!)

The last time (July 2000) we were at Rock Creek somewhere below Blue Sky Lake. It was the third morning, and I woke up and heard the gurgling and asked him if he had rales. He said yes. We packed up and left our group and headed back to Rock Creek. I set up camp, then headed for the ranger station. The ranger was able to radio part of our group to get our vehicle back to the trailhead. (it was a big group, doing 3 three-day hikes, while another group of us did 9 days, and met up with the each group on the way) Our vehicle was at the TH, so SD dropped me off to solo the last part of the trip, while he hung out at Owens Lake for a few days.

We did research trying to find out why, because he was going out as much as I was. Somewhere we read that people with 'lung injuries' are susceptible. He was in a car accident in college and thrown from the car. So after that he accepted the fact that he could get it at any time.

So what he does now:
- Spends at least two days at high altitude (Onion Valley, Cottonwood Lakes or White Mountain) before the start of the trip.
- Diamox for 2 days before the trip
- No alcohol
- no sinus meds

He hasn't had any problems since 2000.

Posted: Fri Apr 27, 2007 8:40 am
by SPeacock
Cheynes-stokes is an AMS associated symptom. Diamox generally fixes the problem

CS goes away after a few days, not like sleep apnea. It is a real pain to try to sleep at high altitude if you have the symptom. Just as you drift off the autotomic response to breath shuts down. So you sleep for about as long as you can hold your breath. Then you start worrying about it :) First couple of days you never get any REM sleep.

So if you notice your partner acting a bit strange early on it might not be the food additives.

Posted: Fri Apr 27, 2007 3:42 pm
by mountaineer
George, spent 24 hours hiking around Whitney Portal, maybe up to 9500', drinking water all day. Spent the next 24 hours around the Bristlecone Pines area, 10400' or so, drinking water all day. Then drove up to the trailhead at 12,000' that afternoon and back down to 10,400' to spend the night. Early the 3rd morning drove back to 12,000' + to start the hike. Not sure what I did wrong in the acclimation process.

I had the worst hallucinations I had ever had. Constantly wanting to just lie down and go to sleep...not caring if I croaked, etc. Somehow, I refused to let myself even sit down to rest as I hiked the seven miles back. I knew if I did I probably wouldn't wake up.


Posted: Fri Apr 27, 2007 9:23 pm
by gdurkee
Whoa!! These are all classic.

Both Mountaineer and Snow Dude are incredibly lucky to be here. Since we run into this enough and since not enough people are totally tuned into the symptoms, I'll outline what I look for from a more practical -- rather than medical -- background.

Onset of bad symptoms on the third day is classic! People are OK on day one, though may have AMS like symptoms: headache, nausea, poor appetite, tired -- but they may not be any worse than anyone else in the party.

Day 2 they're slow. They may be significantly slower than the rest of the party. This is what you need to start paying attention to. Are they 20 to 30+ minutes behind and in otherwise good shape? (but be careful of rationalizing that they're "just in poor shape"...).

Night 2: they're having trouble sleeping. They may (?!?!) find it more comfortable to sleep sitting or propped up. Very bad sign. Fluid is significantly accumulating in the lungs. But don't depend on this as a sign.

The big sign is day 3. The person is very slow. They walk maybe 200 feet, stop, bend over and breathe; another 200 feet (or less). Stop and breathe. They are hurting. All of you are in trouble at this point. You need to:

(Everybody): Descend, Descend, Descend.

If at any point someone is slow to respond to answering questions, making decisions, hallucinating, stumbling -- ANY mental impairment, YOU NEED TO DESCEND IMMEDIATELY! Whatever time it is, you need to get down about 2,000 feet if possible. Even 1,000 feet is helpful. Someone's also got to go for help; whatever time it is. It's a difficult decision to make, but if you can't move the person down, you may have to leave them alone to get help. There's nothing else you can do for them if you can't get them down. Oxygen will help, but the only thing that will cure them is low altitude.

By the time you can hear fluid in the lungs (and in the 70+ cases I've seen, I've only heard rales with a stethoscope maybe 5 times) they could be less than a day from dying. When they're actually gurgling, you don't have much time. Hours, maybe.

"Rales" (and there's some disagreement about the term) describes the crackling you hear, like hair being rubbed together when you listen to the lungs closely. On the off-chance you have a stethoscope, try the right upper lung close to the armpit. But don't get hung up on this as a symptom.

Three things to watch for: They walk for 200 feet, then lean over to breath; high pulse and respiration (resting pulse over 100 and respiration over 20 to 25.); and/or mental impairment. At Crabtree, we literally diagnose just by watching them walk up to the station.

Crabtree Ranger Station (which gets maybe 3 to 5 HAPE cases per year) has a Gamow Bag. This is a vinyl bag that can be pressurized with a foot pump while the patient is inside being given oxygen. It's the only place in the Sierra that has one. If you're near there, scurry down there and grab some people on the way to help carry oxygen and the bag. There's usually (?!) a ranger there every night in August. Ask people on the way if they've seen the ranger. You'll be up all night pumping with the ranger, but it's literally a lifesaver. Try to gather other people and get them to help the patient down in altitude. This is one of those decision things where you have to juggle how bad they are; where the nearest help is; what the chances of getting to help and when are; is there a helispot nearby; should you go past the helispot to descend..... .

None of the decisions are easy. For Whitney (famous HAPE area), there's a landing zone near Muir Pinnacle; just below trailcrest (a big flat spot there) and the summit. Otherwise you've got to get down to the first camp on the east side or base of the switchbacks on the west.

The main symptoms of HACE are a severe headache, unrelieved by aspirin etc., sleepiness/groggyness or altered mental state (hallucinations, slow to answer, can't make decisions etc.). This is obviously another medical emergency. Only descent will help them and you've got to do it while they're competent enough to walk.

Most emergency workers near the Sierra should be clued into these symptoms, but you might run into the occasional person who wants to send a ranger or sheriff to the scene to check on their own. There isn't time. You've got to convince them from the symptoms you note (and write down). Call University Medical Center in Fresno for a consult if you have to.

I don't want to overdo it here. Overall, it's pretty rare, but definitely one of those things everyone should be aware of.


Posted: Sat Apr 28, 2007 3:18 pm
by mountaineer
George, I had never had so much as a headache before even with less acclimitization time. I slept well, no nausea, no weakness, etc. I was going strong on the day of the hike until I just hit a wall suddenly and became violently ill with headache, nausea, hallucinations, dizziness, etc. The weather didn't help, about 25-30 degrees and 60+ mph winds took a lot of strength out of me.