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Physiology/Science<

May 29, 1997



Question:

Thank you for sharing the expedition with us! We are all looking forward to a safe and successful outcome, both in terms of the summit and your findings. A few years ago, I did some research on the effects of Acetazolamide on max and submax exercise at normoxic and hypoxic conditions. It was the treatment of choice at the time for AMS. Can you tell me why Nifedipine is now the preferred treatment? How long does it take to reach therapeutic levels? One of the potentially negative side affects of Nifedipine is periferal edema, and it is contraindicated in cases of CHF. Is periferal edema a problem in climbers on Nifedipine? Is it used to treat already existant HAPE or merely to prevent it? Thanks again for this exciting venture!

Barb Engebretsen
Laurel, NE

Response from Dr. Howard Donner:
Acetazolamide is still the "treatment of choice" for AMS and prevention of AMS. Nifedipine is considered the drug of choice for HAPE (High Altitude Pulmonary Edema) especially when lacking the availability of supplemental oxygen. Therapeutic levels of Nifedipine are reached very quickly especially when initiated with a 10mg bite and swallow dose. This can be followed by the 30mg sustained release form once or twice a day. Peripheral Edema is not typically seen with Nifedipine administration at altitude (unless pre-existing), because cardiac function in HAPE patients is usually quite normal. The biggest clinical side effect would be orthostatic hypotension, but this is rarely seen in hydrated climbers. Nifedipine has been used for both treatment and prevention of HAPE.


Question:

I find your medical information of sats and vitals to be quite interesting. When climbing, what flow of O2 do you use and what are the sats and vitals with activity? Do you ever consider high dose steroid injections (decedron) in times of distress? Also, how about the use of free radical inhibitors or carbonic anhydrase inhibitors?

Scott Hardeman
St. Louis, MO

Response from Dr. Howard Donner:
The flow rate is set at 2 liters per minute. As an example, during a test, David Breashears' oxygen saturation at 21,400 feet was 94% on 2 liters per minute. Our climbers usually do not use bottled oxygen until they are above 26,000 feet. Decadron is used along with descent for cerebral forms of severe mountain sickness. Carbonic anhydrase inhibitors (Diamox) are often used for prevention and or treatment of AMS (acute Mountain Sickness). Our climbers prefer to acclimatize at a rate which avoids symptoms without the use of pharmaceutical agents.


Question:

Greetings Howard,

It's been a while since we've spoken. I have enjoyed your responses to the previously posted questions. Knowing how you love a challenge, my questions are: "what is the one question about altitude that has given you the most difficulty in answering? And, what steps are you taking towards figuring it out?"

Your friend,
Jimmy Rosen
Durham, NC

Response from Dr. Howard Donner:
Hey Jimmy, how's pre-med? Thanks for writing. Probably of most interest to me is the path of physiology of simple AMS, i.e. what causes the headache, anorexia, and malaise. The most lucid hypothesis is reviewed in a journal article by John Krasney entitled "A neurogenic basis for acute altitude illness" from Medicine and Science in Sports and Exercise 1994:26 (2) 195-208. Please give me a call when I am home (mid-June) and we can talk more about this—work needing to be done.


Question:

I would appreciate if you could post this question for me, as my internet mail service does not work properly. Has anyone attempted to modify an oxygen rebreather system for use in mountain climbing? It seems that oxygen is often a limiting factor in an ascent of Everest, and the rebreather would provide a long-lasting oxygen source at nearly body temperature. Also, does any team member have any recommendations for books about Everest? Hope the weather improves. Best of luck.

Steven B. Bird, M.D.
Pensacola, FL

Response from Dr. Howard Donner:
Since the 1950's climbers have experimented with rebreathing systems on Everest. From an informal survey at Base Camp, it seems that these systems have been fraught with problems primarily associated with freezing. I am aware that there are current generation rebreathing systems for marine use that are very compact and efficient. I am not aware of any field testing of these units as of yet.
Response from David Breashears:
Some of the best Everest books are: West Ridge by Thomas Hornbein, Everest by Peter Gillman (photo and editorial analogy), Everest by Walt Unsworth (chronological history), Everest: The Mystery of Mallory and Irvine by Tom Holzel and Audrey Salkeld, Everest the Hard Way by Chris Bonnington.


Question:

This is a two part question.

1. I have read some literature that indicates that women are less susceptible to HAPE than men because their blood doesn't "sludge" as much. Is this true? And if so, why? What are the medical-anthropological implications of this?

2. David Breashears, according to interviews, Krakauer's book, and a recent ABC special, has been very critical of the traffic of climbers and "clients" descending (or rather ascending) upon Everest. Could it be that your team, even in the name of science, is promoting exactly the wrong message? It is common knowledge that Everest is horribly polluted, and becoming a geographical cure for anyone with enough money and chutzpah. (It seems that climbing Everest does have some long range neurological implications—the loss of common sense, as I see that Anytoyli Bokureev & Breashears are back even after the ridiculous loss of life last year.) I *do* wish you all a safe climb. I see that the mountain has already claimed many lives this year as well. Treat her well.

Allegra Blake
Michigan

Response from Dr. Howard Donner:
Although I have heard anecdotes about this, I do not know of any research that supports this idea.
Response from David Breashears:
How could our team be promoting the wrong message if 1) it is only a two-person climbing/filming team versus the average 10-person team; 2) if our purpose for being here is to study the effects of high altitude on the body and brain so we might know more when we (and hopefully other climbers) climb high in the future? To date, none of us on our team (with a combined 26 years of Everest climbing) has been diagnosed with any neurological problems or lack of common sense. Furthermore our combined seven successful summits shows that we may have an excess of common sense. If the increased traffic brought with it experienced Himalayan veterans all would be okay. It is the influx of inexperienced climbers on Everest that brings with it the problems.


Question:

To Pete;

Hello my fellow Coloradoen, and congratulations on your success. While I climb fourtneeres here I will be thinking of you and your team, and hope to do Everest someday. My questions is, when I am mountaineering I lose my appetite and have to force myself to eat, do you guys run into that problem? And second, when you are at high camps and near the summit, are you cooking meals or do you eat things like energy bars to conserve the weight of food, stove, fuel? Good luck, and I look forward to hearing you speak about your trip when you get back to Colo.

Scott McCune
Colorado Springs, CO

Response from Pete Athans:
Dear Scott,

Thanks for your kind message. Altitude and appetite have an inversely proportional relationship. In Base Camp, we have cooked meals prepared, but by the time we get to Camp III and IV, we are reduced to eating snack food and soup. Good climbing.


Question:

During climbs in my local mountains to about 10,000 feet, I have noticed that my hands and feet swell quite a bit, and can cause my boots to become very uncomfortable. When climbing at extreme altitude, is such swelling a factor? If so, do you have a means to control it? Best wishes to all of you. My thoughts and energies are with you.

Dirk Petchul
Orange, CA

Response from Dr. Howard Donner:
There are many reasons for swelling at altitude. At any altitude, especially in the heat, swelling of the hands and arms may occur due to centripetal force of the swinging arms or lymphatic and venous constriction from pack strap compression over the shoulder. At altitude, peripheral edema may occur in some individuals (studies have shown peripheral edema to be more common in women). Peripheral edema at altitude may be benign or may be associated with other symptoms of AMS (Acute Mountain Sickness).

Treatment for peripheral edema involves either resting at the same altitude or very small doses of diuretics which speeds up resolution. I usually don't put patients on diuretics when they are climbing.


Question:

Hi, We read your newsflashes every day! We were wondering what the boiling point of water is at Base Camp and at the higher camps? We looked it up and found that Everest Base Camp has an atmospheric pressure of about half that at sea level which significantly decreases boiling point. Can you put your hand in boiling water at Camp III and IV? We climbed Mt. Adams in Washington a few years ago and noticed that even at 8000 ft. our pasta had a real hard time getting soft. Do you use pressure cookers or do you live with crunchy pasta?

Good luck!
Charles Balogh
Portland, OR

Response from Dr. Howard Donner:
It is possible to grab something from boiling water, but if you leave you hand in the water you will definitely get burned. The boiling point at Base Camp is 175 degrees Fahrenheit (212 degrees at sea level). At Base Camp we use pressure cookers to cook pasta and rice which cuts the cooking time in half. The climbers use pressure cookers on the mountain at Camp II.


Question:

Howard Donner MD,

Greetings from those of us who remain sanely at sea level. Are there physiology experiments other than the neurological testing going on up there? What kinds of diagnostic equipment do you have at Base Camp? If you could have only one piece (excluding a stethoscope) what would it be? Do any of these incredibly buffed individuals (including yourself, of course) ever get anginal type chest pain? Have any/all of these folks ever had a cardiac echo? Would any of these folks LIKE a cardiac echo? (I'll spring for the tape). How on earth did you get this gig? Stay safe, warm and reasonably well O2 saturated.

Susan J.Alexander, MD
San Francisco, CA

Response from Dr. Howard Donner:
We are looking at limited physiologic parameters including oximetry and respiratory rate all the way to the summit. Our main focus is on the psychometric tests. At Base Camp we have access to limited equipment: a pulse oximetry, oto and opthalmoscope, stethoscope and thermometer. If I had to choose only one piece it would be the oximeter—it's a good tool to determine response to oxygen (i.e. guess-timate degree of shunt). There have been case reports of anginal in trekkers, however; I have never heard of an episode of angina in a Himalayan climber. As you know, I always carry Nitrostat SL, Transdermal Nitro Patches, a Beta-blocker, and a highly sophisticated drug called aspirin. There have been a number of studies looking at cardiac function at altitude, including extensive echo cardiography at Operation Everest II (OEII) in Natick, MA in 1985. Amongst others, Dr. Ben Levine, a cardiologist in Austin, TX has been highly involved with echo cardiography as well.


Question:

Hello there on the top of the world. My question is concerning the newsflash that was posted on May 9, 1997. The Sherpa that was treated for HAPE by using a make shift hyperbaric {Gamon Bay}, I was wondering if you could explain how it might be different with the current chambers found at hospitals or flight treatment centers? Also, what kind of depths due you take the patients down to.

Take care and God's speed,
Richard N. Lawson, BS, CCP
Springfield, IL

Response from Dr. Howard Donner:
The portable, fabric hyperbaric chambers that we use are pressurized to relatively low pressures (i.e. 2 PSI), compared with rigid hyperbaric chambers found at medical institutions. Ascent to the summit of Everest reduces the atmospheric pressure by approximately two thirds. Diving to only 20 feet below the ocean increases the pressure by the same amount. As you can see the pressures used for recompressing diving injuries are orders of magnitude higher.


Question:

Hope all is going well! I am very interested if any blood gas studies will be made. Is anyone on the team on any type of medication—vitamins or prescribed medication? Why are no women on the climb? Take care.

Betsy Tingler
Ruther Glen, VA

Response from Base Camp:
There are no blood gas studies being made on this expedition. We are conducting neuro-behavioral tests with our climbers along with taking pulse oximeter readings at various altitudes. There are no women climbing, but we do have a female Co-Producer and Associate Producer at Base Camp.


Question:

Do your lungs have a burning sensation all the time because of the air pressure? How far can you climb without a major rest? Is the wind constant? Or does it come in bursts? How do you keep the tents in the ice without blowing away? Good luck and we are all watching your climb.

George Wild
Montvale, NJ

Response from Pete Athans:
We do not experience any burning sensation. We usually rest about 10 minutes per each hour of activity. Wind is variable. The tents are attached to ice with ice screws or snow pickets.


Question:

To David Carter, I was wondering if any climbers have ever tried taking a blood transfusion before their summit attempt, to see if that would help deliver more oxygen to the brain during the climb?

Good luck,
Dave Roberts
Greenfield, IN

P.S. Maybe we could climb Red River Gorge sometime.
Response from Dr. Howard Donner:
At altitude, it is not simply a matter of oxygen carrying capacity (the amount of red blood cells), but rather how efficiently oxygen can be delivered to the necessary tissues including the brain, heart, lungs and muscles. With increasing red blood cells ("hematocrit"), blood viscosity can increase to the point where profusion (or delivery) is impaired. On ascent to altitude hematocrit goes up almost immediately due to mild dehydration, i.e. an increasing the concentration of red cells. Within weeks new red blood cells are produced at altitude at a rate that the body can use efficiently. In 1983, climbing scientists on Everest attempted to remove red blood cells, and found no change in their performance.


Question:

What effect does high altitude have on metabolism? Is the extreme cold also a factor? What changes in weight can be expected as a result, especially at Camp IV and above?

W.L.
Kansas

Response from Dr. Howard Donner:
Metabolism is a very broad term. Initially on ascent, there is an increase in adrenaline-like compounds which increase metabolic rate and result in increases in blood pressure and heart rate. The body also attempts to become more efficient by increasing mitochondrial density and increasing oxidative enzymes (enzymes involved in metabolism). Mitochondria are the power factories for human cells. Interestingly, actual metabolic depression of membrane Na+/K+ ATPase, in the brain, is not seen at levels of hypoxia typically encountered in climbers. This means that the brain remains normal from an energetics (metabolic) standpoint. If by metabolism you mean performance, VO2 Max (maximal oxygen uptake) has been shown to decrease steadily with increases in altitude. The extreme cold requires greater caloric intake to maintain normal body temperature, and at altitude climbers feel they have more trouble staying warm. The amount of weight loss seen in climbers at Mt. Everest is variable. Our climbers often lose little weight. Historically, Everest climbers have lost up to 40 lbs or more on a single expedition. Climbers arriving with less excess body fat tend to lose less body fat.


Question:

Much of this climb is focusing on the affects on the mind and body at high altitude. How does your body feel when you return home (assuming "home" is somewhere around sea level) after a long period of time at very high altitude? Do you feel super human with all those extra red blood cells? Do you find that your resting heart rates are even lower than they were before you began your climb? And emotionally, do you find that you suffer something akin to separation anxiety or post-partum depression?

Thank you and best wishes for a safe and successful expedition.

Larry Buttrey
Long Beach, CA

Response from David Carter:
When I return from an expedition, I have lost so much weight while living at high altitude that I sleep for a couple of weeks. I usually don't feel like doing any exercise for at least a month—much of that is due to mental exhaustion.


Question:

I have been in contact with Dr. Peter Hackett who referred me to this page in regards to my senior project. I am studying the effects of altitude on myself and two partners during a three week climb of Denali's West Buttress. I will be monitoring for cognitive, sensory, and motor deficits.

During my extensive literature review finding specific examples of the types of tests administered by other investigators has been quite difficult. So far one of the most helpful resources has been this page and the tests posted on it and created by Gail Rosenbaum. I was hoping that one of the investigators might be able to offer assistance in finding more tests like the ones posted here. Specifically the Stroop test, Verbal Puzzles, and Remembering Sentences. My goal is to find enough of these tests to collect data twice daily on three people for three weeks. I am also interested in where I might find an oximeter to measure pulse rate and oxygen saturation, as well as how to measure lung size and capacity. Is lung capacity the same as forced vital capacity? And would a spirometer be the instrument to measure it? What is peak expiratory flow? Are you measuring finger-tapping speed? If so how? Is the Automated Performance Test System (APTS) being administered and do you know where the software can be found? How is HVR measured?

I appreciate any help you may be able to offer. Anything will surely be of help, especially considering I leave May 30th for the climb.

Thanks, and Climb On!!
Greg Barrett
Anchorage, Alaska

Response from Dr. Howard Donner:
A good source for lightweight pulse oximeters is Chinook Medical Gear Inc. (970-328-2100) in Eagle, Colorado.

For the neurological tests the following papers will be of assistance:

"The Cost To The Central Nervous System Of Climbing To Extremely High Altitude," Tf. Hornbein,

"Do Climbs To Extreme Altitudes Persistent Memory Impairment After High Altitude Climbing," G. Cavaletti,

"Brain Damage After High-Altitude Climbs Without Oxygen," G. Cavaletti,

"Long-Lasting Neuropsychological Changes After A Single High Altitude Climb," G. Cavaletti,

"Neuropsychological Functioning After Prolonged High Altitude Exposure In Mountaineering," Cf. Clark.


Question:

I have been interested in the subject of Acute High Altitude Sickness since my brother, Edward (also a former Cheley Camper as is Dr. Tom Hornbein), died of it during a 1976 ascent of Mt. McKinley. The weather was bad and the party could not get him to a lower elevation. The malady seems to strike without a great deal of predictability. The climber can have previously gone to an elevation several times before without incidence, and then for some reason on a subsequent ascent to that elevation be stricken. Have you been able to identify any precursors that might signal its onset or any predisposing factors? Is there a threshold elevation where it presents itself and an elevation above which it seems to be of little problem? What precautions have the team taken to avoid it and why was it believed that this course of action would prevent the onset? If that has not been totally successful in avoiding High Altitude Sickness, what would you have done differently? Who has had it, at what elevations?

Jim Guleke
Austin, TX

Response from Dr. Howard Donner:
Interestingly there have been numerous recent observations that climbers with preexisting upper respiratory infections (often viral) are predisposed to HAPE (High Altitude Pulmonary Edema). This may explain some cases of seemingly random HAPE in individuals whose prior climbing history suggested no predisposition.

Climbers often report the unexpected onset of HAPE. With closer scrutiny of the ascent profile there are often subtle changes from one climb to the next. An extra staging or rest day at the same altitude can influence the potential for development of HAPE. Some have conjectured that other variables including diet (ie, salt intake) may cause changes in susceptibility but this has been poorly studied. Additionally, the use of pharmaceutical agents, such as nifedipine, may be used to prevent HAPE in known susceptibles.

There is no elevation above which HAPE is no longer a potential danger.

The best indication that our team can avoid complications with HAPE is a clear history of no prior problems. With the human body, there are never guarantees but a pristine prior history is extremely reassuring.


Question:

Greetings from Washington- the monsoon has decided to visit us before it goes on to Asia- lots and lots of rain. I hope your weather conditions are better. My question is how does the altitude affect your senses like smell, taste, hearing and seeing? Are they dulled or enhanced the higher you go? How about your sense of balance- do you experience vertigo? Thank you and best of luck for a safe summit day.

Colleen Merrill
Langley, WA

Response from Dr. Howard Donner:
Smell and taste are definitely diminished at base camp (17,600') and at the higher camps. The return of these senses is best appreciated upon descent to lower elevations.

With symptoms of AMS (Acute Mountain Sickness) balance can be affected, however, in a well acclimatized climber balance should be normal. At extreme altitudes, climbers suffering from chronic hypoxemia (low blood oxygen) have described difficulty with balance. Other factors that affect climbers' balance include dehydration, hypoglycemia and exhaustion.


Question:

My Physical Science and Astronomy students would like to know if any of you were particularly interested in science when you were in 8th grade. Some of them don't think science has any practical applications to every day life. How has it helped you out in the area of physics? Good luck and thank you.

Marg Freeman
Boise, Idaho

Response from Ed Viesturs
I'm a veterinarian and am intrigued by physiology. Climbing and exercise physiology go hand in hand.


Question:

I am a first year medical student at the Univ. of Massachusetts Medical Center. I would like to know if any of the four climbers have ever had any episodes of HAPE or HACE on any previous climbs? Also are you planning on publishing any of your results? I plan on doing research in high altitude physiology and I will be following this research expedition with much interest. Good luck.

Michael Todd
Millbury, MA

Response from Dr. Howard Donner:
All of the climbers have had symptoms of acute mountain sickness at one time or another including: lethargy, lack of appetite, headaches, and sleeplessness. None of the climbers have ever developed severe forms of mountain sickness such as full blown HAPE or HACE.

The results of this study will eventually be published. Dr. Tom Hornbein at the University of Washington will be able to offer you more specific information on upcoming publication of this data.


Question:

I am interested in whether you are testing the Sherpas during your climb - 1. to see how their test results would compare to your results and 2. to help understand how their bodies handle the high altitude stresses. Are they adversely affected by going down to sea level like we are by going up so high? Best of luck!

Betsey LeBreche
Del Mar, CA

Response from Dr. Howard Donner:
Yes, our sirdar Jangbu Sherpa will be tested along with the other climbers. Interestingly, there has never been any indication of a "low altitude" sickness in high altitude natives descending to lower altitudes. I have often heard local Sherpas speak of "low altitude" illness in yaks that typically inhabit regions of the Khumbu above 14,000 feet. However, many yaks live in low altitude zoos around the world. The illness that the yaks developed when descending to low altitude is probably due to exposure to numerous infectious diseases transmitted by lowland cattle to which the yaks have not developed immunity.


Question:

Many mountaineers take prescription drugs to help negate the affects of altitude. This practice seems most common in areas where climbers ascend from low elevations quickly and have little time to acclimate. Is the use of any type of medication the standard on Everest? We are with you in spirit.

Kerry, Jodi, Mike, & Kip Hanson
Shorewood, WI

Response from Dr. Howard Donner:
Most climbers on 8000-meter peaks prefer to acclimitize without the use of prescription drugs, when possible. However, the climbers generally carry a number of high altitude prescription drugs for use in emergencies. These drugs include: Nifedipine for High Altitude Pulmonary Edema (HAPE), Decadron for High Altitude Cerebral Edema (HACE) and Diamox. Even in an acclimitized climber, Diamox is often used in very small doses prior to bedtime to decrease or eliminate periodic breathing. This makes for a much more restful night's sleep at extreme altitude.


Question:

To the Team: I've summited Mt. Rainier a couple of times and know the air gets thinner the higher you get above 12,000' My question is how much more of an effort and how much more oxygen deprived do you get as you accent above Camp I. Is food (fuel) carbo loading as important or more important as breathing correctly? Thanks for your insights.

Mike Rindahl
Seattle, WA

Response from Dr. Howard Donner:
Although proper breathing can enhance air exchange, no one is able to maintain voluntary changes in ventilation 24 hours a day. Different forms of purse-lipped breathing to enhance expiratory positive airway pressure (EPAP) have been tried. EPAP improves air exchange by holding open the alveoli at the end of expiration increasing air exchange. Although probably effective these modified breathing patterns are impossible to maintain, especially during sleep—a very important time for acclimitization.

There have been numerous studies looking at carbohydrate intake at altitude. There is some suggestion that eating foods with a lower respiratory quation (rq - a ratio that looks at the amount of oxygen needed to metabolize food substrate) may be beneficial, although studies have been equivocal.


Question:

Hello to David Carter,

I grew up with you in Sylvan Ridge. I know that many Hoosiers, myself included, are praying for your safe return. I wondered if this climb was any easier, either mentally or physically, because of your earlier climb on Everest? Also, how far up the mountain are the laptops going? And, what kind of computer equipment is there?

Nancy Johnson Heck
Carmel, Indiana

Response from David Carter:
Dear Nancy,

Yes. The climb is a lot easier because of my earlier attempt on Everest. This time I know what to expect and it makes things much easier for me. Mentally, I'm not as stressed as I was in 1991. The computers live full time at Base Camp. We are currently using two Apple Powerbook computers (one is a 1400c and the other is a 5300cs) that connect daily to our satellite phone so that we can download all the e-mail coming into our site. Thanks for your support.

All the best,
Dave Carter


Question:

Hi guys. Hope that everything is going well on the mountain. My question: what is the difference in oxygen levels at the top of the mountain from what it is at base camp? Also, how is the team coping with the altitude sickness they must be experiencing?

Robert & Alicia Tindall
Lexington, KY

Response:
At the summit, there is 1/3 of the oxygen available at sea level. At Base Camp it is about half. To date, none of us have experienced altitude sickness.


Question:

Hello and congratulations on your good progress so far. I know that the longer you're exposed to the thin air at altitude the more adapted you become. However, from your past experience what determines the approximate altitude at which you no longer can adapt and altitude sickness begins? Climbing abilities aside, are certain individuals just more adaptable than others or can anyone adapt given optimal training, physical conditioning and diet? Good to luck to you all and especially to fellow Hoosier and friend David Carter.

Paul Kite
Response from Base Camp:
There is no ideal person yet who adapts better to altitude than others, but there are some subtle indicators that have been found that may aid in a person's performance at altitude. By that same token, there are some people whose profiles will say they won't do well, and yet they end up performing well at altitude. Some of the indicators that we think will aid someone at altitude (regardless of physical training and diet) are lung size and capacity, blood oxygen saturation, and hypoxic ventilatory response. There is some evidence that having more intracranial space between your brain and skull will make you less prone to headaches which may make you more prone to acclimatizing. We generally consider going to Camp III as the highest point one can adapt to. We believe that a night or 2 at 24,500 (Camp III) feet is the highest one can positively adapt to. If you're like Ed Viesturs and want to climb without oxygen to the summit a trip to the South Col is probably beneficial. We have not seen any climbers, to date, who can adapt to altitudes beyond Camp IV (26,000 feet). At this point, humans generally deteriorate and become weakened with time.
Dr. Tom Hornbein adds:
Regarding predictors of performance, there are indeed a few physiologic hints but when you get down to the moment of truth, putting one foot above the other day after day, it's what's in the head that seems to count most, that is stubborn commitment (coupled with judgment helps). I suspect our team will concur.

It's generally thought that the maximum altitude at which humans can stay permanently is about that of the Everest Base Camp. This belief is based on the simple observation that that's the highest known habitation, namely at a mining community in Chile. I like to think that above that altitude, man is a transient guest. Initially the benefits of acclimatization are dominant, so net performance improves, but with time a process of wasting—so-called high altitude deterioration—becomes dominant so if we stay too high too long we begin to go downhill (figuratively and likely literally as well). The timeline for crossover of these two competing forces of opposite sign is hard to define but both are probably accelerated the higher one goes. And as the process of acclimatization becomes more complete and slows, the process of wasting becomes increasingly dominant.

Above 8000 m. (approximately 26,000 feet) we don't know whether the rate of acclimatization is increased but we sure do believe m one can linger if not thrive is measured in hours to a few days. These impressions are based on anecdotal experience and the climbers are that the time one can linger if not thrive is measured in hours to a few days. These impressions are based on anecdotal experience and our team of climbers are living with as much of this as anyone has.


Question:

Hello Liesl and David! Hope all that traffic on the mountain isn't slowing your work down? How have you been managing? We're doing our own physiology and endurance project and are wondering if we could get the team's resting, walking around basecamp and active pulse rates at whatever altitude it's taken. We'd like to compare ours with yours. We'll also be collecting data on breaths/minute at rest, walking and active moments. Could you give us that data, too? It could be at different times, convenient to you. Thanks. Warm hugs, Nancy Ferguson's third graders. PS. We love your webpages and read them almost every day.

Nancy Ferguson's Third Grade Class
Newton, MA

Response from Base Camp:
Hi to Nancy Ferguson's third grade class from Liesl and David. Here are a few stats on our pulse rates: Our resting pulse rates at Base Camp are around 60 - 65. Walking around camp, our pulse rates are around 85 - 95. Working around camp or hiking is around 130. David and Pete report that on a hot day in the Western Cwm carrying a load their pulse rates are around 160.Breaths per minute at Camp II while lying on back in tent is about 22 per minute. It varies at ABC from 22 at rest to 40 at mild work to 60-70 at hard work. All our best and good luck with your own results.


Question:

Hello: I am a physician in San Diego. Are you all taking medications to help with altitude, such as Diamox or Decadron? What are your medical contingency plans if someone starts to get altitude sickness? Do you have a physician along with you? This is an interesting study. Are there any control groups involved? The results that you get will be much more valid if you are comparing results to a similar group at sea level, as well as at various altitudes at the same time. Unless variables such as medications and oxygen use are taken into account, your results will be skewed and possibly meaningless. (You have probably already thought of all this, I'm sure). Good luck! I wish you all well on your endevour.

Sincerely,
Robert Power, MD
San Diego, CA

Response from Base Camp:
Some of us have taken Diamox to enable us to sleep (and breathe) at night. If someone becomes ill from altitude sickness, we generally adhere to the rule of sending them down to a lower altitude. In extreme cases we might put them in a Gamow Bag to temporarily alleviate the symptoms and then send them down. Diamox and Dexamethazone are always options, too. We will have a physician (Howard Donner) joining us in about 10 days. But, there are many doctors here at Base Camp who are familiar with mountain medicine. There is also a clinic at Pheriche at 14,000 feet which is about a day's walk from here. There are already existing control groups that have been studied at varying altitudes in the past years. Our intention is to study 4 elite climbers who have excelled beyond others at high altitude and are willing to partake in specially designed tests on Everest. We are a small sample, but we are very interested in what the data on these 4 climbers will tell us about peak performance at extreme altitudes.


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