Mt Whitney Zone
Posted By: Steve C AMS at 10,000 feet - 08/10/17 04:27 PM
Here's an AMS story that ended in a helicopter evacuation.

The hiker started at 10,000 feet elevation at Horseshoe Meadows. He felt sick after sleeping overnight there, but proceeded to hike to near Crabtree Meadows. His condition deteriorated to the point he could not walk out.

Here's the story:   A John Muir Trail Thru Hike Derailed
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/11/17 06:07 PM
Thanks for posting this Steve

First thought is that sleeping first night above 10,000 ft breaks the rule of intermediate heights before sleeping that high. Sleeping height impacts risk of AMS more than daytime for a physiological reason. Some people cannot tolerate a rapid height advance. Everyone has their own tolerance level getting started as well as ceiling later on.
Posted By: Steve C Re: AMS at 10,000 feet - 08/11/17 08:38 PM
Harvey, maybe this is mostly anecdotal, but for myself, driving directly to 10k elevation and sleeping has worked well for me. And I've been recommending people do that in preparation for their Whitney adventures. I usually take 62.5 mg Diamox in the morning and before that first night, too.

I've only seen a few rare cases, like this one, where people were susceptible to definite AMS problems doing this. It is pretty clear for these few that their "intermediate height" for a first night is somewhere below 10k.
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/11/17 10:43 PM
Originally Posted By: Steve C
I've only seen a few rare cases, like this one, where people were susceptible to definite AMS problems doing this. It is pretty clear for these few that their "intermediate height" for a first night is somewhere below 10k.

Steve , we are both correct. Most people get away with it, but a few are very susceptible. Unfortunately there is no good sea level test to predict this, only experience up high. First time, or even subsequent ones , can be hard. If they gave him O2, I wonder if if had more than AMS, but also HAPE.

AMS usually starts to get better once the decision to descend has been made or with only short descent. Generally speaking, HAPE and / or true exhaustion and/ or other illness would take longer.

A bit smokey in Mammoth.
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/11/17 10:57 PM
Originally Posted By: Harvey Lankford
...A bit smokey in Mammoth.


Empire Fire in YNP (750 acres) and Butte Fire (570 acres) in Sierra National Forest perhaps.
Posted By: terraelise Re: AMS at 10,000 feet - 08/12/17 01:20 AM
I'd like to note that you never know when AMS will strike or how hard. I have hiked all over and usually the most I get is a lack of appetite. I have been fairly lucky and altitude is mostly about thin air for me to this point.

The only time I really got questionable symptoms was at lower elevation: hiking SoCal's San Jacinto from the tram. Once, of the three times I have done it, somewhere near switchbacks at 9k I had to sit and rest and eat - a longer break than I typically ever do for any reason. I'm sure it was the extreme of coming from so low up the tram to so high that did it (I also live very low in the OC) - plus... Aunt Flo (sorry guys, but it has to be noted).

I have heard many stories of experienced high elevation hikers suddenly having severe AMS symptoms on a hike but never before or after: fine on Kilimanjaro (19.3k) then sick on San Gorgonio (tops out at 11.5k). Some perfect storm of conditions? I don't know, but I'd warn that just because you haven't had it before doesn't mean you won't. FWIW
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/12/17 02:13 AM
Originally Posted By: terraelise
I'd like to note that you never know when AMS will strike or how hard. I have hiked all over and usually the most I get is a lack of appetite.

The only time I really got questionable symptoms was at lower elevation: hiking SoCal's San Jacinto from the tram. Once, of the three times I have done it, somewhere near switchbacks at 9k I had to sit and rest


Yep, 9000 will do it, in fact, current official threshold is 8000 and some talk of 7000 .

Yep again, a lot of unpredictability about who , when, where, other factors


Need more than loss of appetite at high altitude to make a diagnosis of AMS. See Lake Louise Score of AMS
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/12/17 07:29 PM
terraelise, I call that area to the summit "Squat Valley" -- where people take a rest along and also mix it in with nature calls. If I remember correctly this area is around 10k elevation. I, too, feel a little woozy at this section when hiking San J. Just a few mountaineer's breaths and I proceed with no adverse effects.

People have difficulty with this and I feel the root cause of this is the Palm Springs Aerial Tramway. The sea level devils from OC and LA have stayed in Palm Springs (elevation 479 feet) at a guest's house or posh hotel. They drive to the Valley Station (2,643 ft. elev., 2,164 elevation change). They hop on PSAT for the 12 minute or so ride (2.5 miles) to the Mountain Station (8,516 feet; 5,873 ft EC).

Over 2.5 miles traveled and 5,873 feet of EC in 12 minutes, to me, may be too much for some people.

I am also curious...could nitrogen be lower as well at higher elevation? Air is 78% nitrogen and 21% oxygen. Decompression sickness (the bends). Altitude and altitude decompression sickness.

Could there be a correlation?

Could nitrogen be the culprit?

Just an observation.
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/12/17 10:00 PM
The root cause of altitude illnesses is reduction in barometric pressure AND the bodies responses and malresponses to it. The loss of "driving pressure" limits the availability of oxygen. And yes, divers who have been low have rules about when they can fly home because commercial airliners cabin pressure is , guess what,the equivalent of 8000 ft. Too rapid a change in pressure of either O or N can cause various forms of barotrauma
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/12/17 11:10 PM
So, it is not a lack of oxygen or nitrogen, it is the air pressure that makes us sick from the barotrauma. It is starting to make sense. Thank you, Doc!

When an IED explodes, it causes blast-induced barotrauma. If it doesn't kill you, it knocks the wind out of you which is actually the low air pressure after the shock wave passes.

Atomic bomb experiments show the initial blast and shock wave that causes low pressure. When the shock wave dissipates, the surrounding air rushes back in.

So, if you live and train at altitude...I remember the 1968 Olympics in Mexico City. The athletes trained at altitude in Oregon to prepare.

I like this subject.
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/13/17 01:12 AM
Originally Posted By: + @ti2d

I like this subject.


Me, too. Think about this one: if you are at 40,000 ft and breathing 100% O2 at ambient pressure you will die.

Must have pressure. My use of "barotrauma" was my exaggeration as no one can climb or descend on two feet that fast. A better word for the benefit of pressure is "oxygen cascade" Look up how O2 gets to the mitochondria.

Why die at 40,000 ? Jet pilots wear pressurized masks. Otherwise their entire cabin would need to be pressurized. O2 alone will not work

Resting after a short hike in Mammoth. Acclimatizing
Posted By: wagga Re: AMS at 10,000 feet - 08/13/17 06:30 PM
Quote:
I like this subject


ACE gene?
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/14/17 04:07 AM
Originally Posted By: wagga

ACE gene?

        ACE genotype and Successful Ascent to Extreme High Altitude

Posted By: SoCal Jim Re: AMS at 10,000 feet - 08/14/17 05:28 AM
Huh. Interesting. Evidence of genetic differentiation related to performance at extreme elevations.
Posted By: Marcus Re: AMS at 10,000 feet - 08/14/17 10:03 AM
Me and some buddies attempted to hike up to Whitney Peak a couple of weeks back - one of us got AMS symptoms just before Consultation Lake.

We ended up camping at "Consolation Lake" and heading back down the following morning.

What possibly made it worse was that we had visited Bad Water and Death Valley a couple of days previous to the hike up Whitney.

So we effectively went from the lowest point in the USA to the highest - that probably didn't help! grin
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/14/17 02:59 PM
Originally Posted By: Harvey Lankford
Originally Posted By: wagga

ACE gene?


https://www.ncbi.nlm.nih.gov/pubmed/18081503 ACE



Let me guess...

New gene therapy that will replace Diamox in injectable form.

Disclaimer: Avoid prolong use or hyperactivity. May cause swelling of the extremities. Frequent urination or excessive bowel movements may occur. WAG bag sold separately. Available at your local drug store. Consult with your doctor before taking.

Dr. Lankford: In English please for those who may not speak the lingo...
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/14/17 11:29 PM
Originally Posted By: + @ti2d


Dr. Lankford: In English please for those who may not speak the lingo...


Ha! That is easy.

We are not all alike!

Said another way, if you are of purebred , many centuries genetically adapted Tibetan heritage, then some of you have a metabolic advantage over the rest of us slugs
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/15/17 02:55 PM
Ah, much better...I confess, it was me who couldn't decipher the study.

So, some of us have an ACE up our sleeves?

Why I never...

Won't play poker with them folks...

Genetic cheaters... grin
Posted By: Steve C Re: AMS at 10,000 feet - 08/15/17 04:26 PM
Originally Posted By: Harvey Lankford
We are not all alike!

Said another way, if you are of purebred , many centuries genetically adapted Tibetan heritage, then some of you have a metabolic advantage over the rest of us slugs

Not just Tibetans:   "...and has a greater than normal frequency among elite endurance athletes..."

Endurance athletes may rise to their level of higher output more easily, because they too carry this particular genetic setup.
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/15/17 04:57 PM
That's you, Steve, aka endurance athlete!
Posted By: Steve C Re: AMS at 10,000 feet - 08/15/17 06:41 PM
> aka endurance athlete!

Yeah, I wish! Far past my prime. And there are many who have far surpassed anything I might have even hoped to do.
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/15/17 07:01 PM
Look at the bright side, at your "age" you are doing things other people your age dream about or sit in front of a television wishing they could do that...
Posted By: over1812 Re: AMS at 10,000 feet - 08/20/17 06:16 AM
Originally Posted By: + @ti2d

I am also curious...could nitrogen be lower as well at higher elevation? Air is 78% nitrogen and 21% oxygen. Decompression sickness (the bends). Altitude and altitude decompression sickness.


Ratios of elements stay the same. As Harvey pointed out, lower pressure means the molecules are further apart, so you get less oxygen than you would in a normal breath at sea level.
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/20/17 05:58 PM
Same percent O and N at higher mountain altitude, only the pressure changes
Posted By: + @ti2d Re: AMS at 10,000 feet - 08/21/17 02:50 PM
Interesting...

Thank you for the information!
Posted By: david_garza Re: AMS at 10,000 feet - 08/21/17 09:12 PM
Originally Posted By: Steve C


"After 8+ months of planning ..." I skimmed, but didn't see mention of prep hikes before setting off solo at 10,000, which seems negligent.
Posted By: Steve C Re: AMS at 10,000 feet - 08/22/17 05:55 AM
Originally Posted By: david_garza
"After 8+ months of planning ..." I skimmed, but didn't see mention of prep hikes before setting off solo at 10,000, which seems negligent.

If a person is in relatively good shape (regular workouts), and starts out relatively slowly (shorter mileage the first few days), prep hikes aren't mandatory.

His problem was a major susceptibility to the altitude -- far greater than most people.
Posted By: david_garza Re: AMS at 10,000 feet - 08/22/17 10:04 PM
That's what I meant -- he didn't know how susceptible to altitude he was until it was too late. If he'd at least done an overnight with a clear and easy bailout, a helicopter wouldn't have been needed.
Posted By: WanderingJim Re: AMS at 10,000 feet - 08/23/17 04:10 AM
Originally Posted By: Marcus

What possibly made it worse was that we had visited Bad Water and Death Valley a couple of days previous to the hike up Whitney.

So we effectively went from the lowest point in the USA to the highest - that probably didn't help! grin


I did that as a lark two years ago when I did my first summit of Whitney. Fortunately, didn't keep me from successfully summitting, but it was probably a bad choice.

But I was young and foolish back then. smile
Posted By: Steve C Re: AMS at 10,000 feet - 08/23/17 06:15 AM
Originally Posted By: WanderingJim
I did that as a lark two years ago when I did my first summit of Whitney. Fortunately, didn't keep me from successfully summitting, but it was probably a bad choice.

But I was young and foolish back then. smile

Here's the right way: 7 years ago, now, Bob R organized an 80th anniversary of Norman Clyde's Highest-to-Lowest in a day. We camped on the summit, then hiked down and drove to Death Valley to watch the sunset from Badwater. Fun times!

      Links: Sunrise, Sunset -- 80 years after Norman Clyde

      Bob Rockwell's album: 2010-09-28 Whitney to Badwater
Posted By: Steve C Re: AMS at 10,000 feet - 08/23/17 03:38 PM
Another current story from Colorado:

Altitude sickness kills college student on hiking trip



From the article:
A Pennsylvania college student died last week from altitude sickness during a hiking trip in the Rocky Mountains, according to relatives....
... the 20-year-old started vomiting on the Conundrum Creek Trailhead. ...which begins at 8,765 ft. and reaches an elevation more than 11,000 ft. ....student had already died by when they finally reached her at 5 a.m. Friday.


Vomiting at the trail head is a NO GO situation!!!
Posted By: rFan Re: AMS at 10,000 feet - 08/23/17 04:34 PM
wow.. the altitude is not even that high.. I wonder if they could have somehow "forced" her to descend vs. staying there waiting for help..
Posted By: Harvey Lankford Re: AMS at 10,000 feet - 08/23/17 04:47 PM
Although the "rule" is that " illness at altitude is altitude illness until proven otherwise", I do not see enough evidence in that limited report to be sure of the diagnosis. Vomiting alone does not kill quickly unless, say, it is a manifestation of HACE, rare at that altitude to begin with. Above 8000 ft does at least fit with the threshold for altitude ilnesses, usually mild. An autopsy would be useful.

The most famous abdominal-symptom death at (extreme) altiude was the daughter of famous climber Willi unsoeld. He had named his daughter Nanda Devi after the mountain. When she was about 19 or so, she accompanied him to her namesake mountain and died there . There were medical clues in her case that suggested a bowel obstruction or other intraabdominal catastrophe that just coincidentally occurred on the mountain
Posted By: futbol Re: AMS at 10,000 feet - 08/23/17 05:48 PM
I vomited at Upper Boy Scout Lake early July, but ~45 minutes later I felt great and we continued up Mt. Russell.

I had acclimated the night before at the portal campground.

Are there any tell tale signs that you should turn around and descend?

A guy in a group that went up Mt. Whitney last year brought along a device that measures altitude sickness but I forget what it was called or how it works.

edit: I asked him. It was a pulse oximeter.
Posted By: Steve C Re: AMS at 10,000 feet - 08/23/17 07:43 PM
I think the first article I linked to above mis-wrote "trailhead" where it should have been "trail".

There are dozens of news reports out now:   Google news: Susanna DeForest

They all report the same thing -- 6-7 miles into the hike, she started vomiting, and felt dizzy.

Harvey could be right -- some other issue may have caused her death.
Posted By: Bobby49 Re: AMS at 10,000 feet - 08/23/17 08:40 PM
Originally Posted By: futbol

A guy in a group that went up Mt. Whitney last year brought along a device that measures altitude sickness but I forget what it was called or how it works.

edit: I asked him. It was a pulse oximeter.


A pulse oximeter does not measure altitude sickness. It measures your pulse rate and your blood oxygen saturation.

Many people have an unreasonably high pulse rate when at high elevation, but it never stops them. Also, many people have an unreasonably low blood oxygen saturation, but it never stops them. It probably slows them down a lot. The oximeter can give you some indication of how close to collapse you are getting.
Posted By: futbol Re: AMS at 10,000 feet - 08/23/17 09:59 PM
Originally Posted By: Bobby49
Originally Posted By: futbol

A guy in a group that went up Mt. Whitney last year brought along a device that measures altitude sickness but I forget what it was called or how it works.

edit: I asked him. It was a pulse oximeter.


A pulse oximeter does not measure altitude sickness. It measures your pulse rate and your blood oxygen saturation.

Many people have an unreasonably high pulse rate when at high elevation, but it never stops them. Also, many people have an unreasonably low blood oxygen saturation, but it never stops them. It probably slows them down a lot. The oximeter can give you some indication of how close to collapse you are getting.


Good info. Thanks!

The one person in question (he expressed difficulty) was measured and was getting close to the unconscious level -- so he was promptly escorted down the trail. I forget what that level was.
Posted By: Bobby49 Re: AMS at 10,000 feet - 08/25/17 05:50 PM

There is no such level, at least not a standard one. Everybody has their own level. You need to use a pulse/oximeter a few times in order to get a calibration check. One person might be ready to collapse at 90%. Some might be at 80%. A few might go to 70%. And then there is Ed Viesturs.
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