High Altitude Awareness Table of Contents Kirk Salveson Manager Field Science Support Raytheon Technical Services Company Polar Services 7400 S Tucson Way Centennial, Colorado 80112-3938 USA 303.790.8606, ext. 32215
September 25, 2003 Welcome to the on-line Altitude in Antarctica course. This course is designed to help you gain awareness regarding our body’s reactions and adaptations to high altitude. Our first concern at RPSC and in Field Science Support is for the safety of each individual in your group. While altitude is often not recognized as a medical threat, our experience in the deep field has taught us that high altitude combined with the harsh Antarctic environment can create life-threatening situations. All of us react differently to altitude and it is important for everyone working “up high” to recognize altitude effects on themselves and their team members. This on-line module is designed to streamline your field safety training while in McMurdo. We hope this presentation will increase your awareness of altitude complications long before you deploy to the ice. By reading this presentation and taking the quiz you will receive the material that was traditionally offered in the altitude class. Upon your arrival at McMurdo if you have read the material and taken the quiz, our field safety training instructors will offer a short practical class where you can ask additional questions and most importantly operate a Gamow bag which you will have in your field equipment. Thank you for taking time from your busy schedule to prepare for your Antarctic field season. We appreciate any comments that you may have on this information, and other ideas to electronically present more field safety training material. Best Regards, Kirk Salveson Manager, Field Science Support Raytheon Polar Services Kirk.salveson@usap.gov
Introduction
Congratulations. You have the opportunity to work in one of the most extreme environments on earth. If you are viewing this presentation, you will also be working at high altitudes. By addressing altitude issues before deployment, you will be better prepared mentally and physically. This also gives you the opportunity to research and look beyond the information presented.
Altitude Scale
• High: 8,000 to 12,000 feet.
• Very high: 12,000 to 18,000 feet.
• Extreme: over 18,000 feet.
• Most high altitude camps are at an altitude of 8,000 to 12,000 feet.
• You will be arriving from sea level.
• However uncommon, altitude illness signs and symptoms can be seen at elevations as
Basic Physiology of Altitude (Or What’s Going On Up There?)
• Oxygen remains at about 21% as altitude increases.
• Barometric pressure decreases as the altitude increases.
• With the decrease of barometric pressure, partial pressure of oxygen decreases.
• Due to the reduced partial pressure of oxygen at altitude, the body has to work harder to
push oxygen from the lungs into the bloodstream.
• Oxygen losses it “pushing power” to diffuse from the air sacs to the bloodstream.
• The result is less oxygen available to the body (hypoxia).
Altitude and Polar Regions
• Barometric pressure is affected by its distance from the equator.
• In polar regions, hypoxia (inadequate oxygen in the lungs and blood) develops at lower
• A low-pressure weather system can further reduce barometric pressure.
• Extreme cold provokes altitude related problems.
How does this relate to you?
• It means that your body has to function with less oxygen.
• Your body needs the same amount of oxygen at altitude as it does at sea level.
• Your body has to adjust or acclimatize to the altitude.
• Acclimatization is the process by which your body adjusts and adapts to the decrease in
How the body acclimatizes
• Ventilation: The depth and rate of breathing increases to provide more oxygen to the
• Cardiac output: Heart rate increases in order to allow the heart to pump more blood
• Pulmonary artery pressure: Pressure elevates to help “push” oxygen from the air sacs
• Red cell production: The increased concentration of RBCS allows the blood to carry
• Diuresis: Urinary output increases to rid the body of bicarbonate.
• Enzyme and tissue changes: Allows efficient oxygen transport and use of oxygen by The acclimatization process is different for everyone
• Time varies for the different processes just discussed.
• Each individual varies widely in the ability to acclimatize, both in degree and time.
• The average time for acclimatization is three to five days.
• Prior experience at altitude does not exclude you from altitude related illnesses.
• Some individuals are unable to acclimatize at all!
Normal Body Responses To Altitude
• Remember these are normal responses. It is your body’s way of adapting to altitude! How To Achieve Acclimatization
• Graded ascent unfortunately we do not have this opportunity. We are normally flown
• Avoid alcohol, tobacco, depressant drugs (like sleeping pills, narcotics).
• There are several ways we can prepare for altitude, both prior to departure and once we
arrive. We will get to them later first altitude illness
Common Altitude Illnesses
• Acute Mountain Sickness (AMS).
• High Altitude Cerebral Edema (HACE).
• High Altitude Pulmonary Edema (HAPE).
• Several medical problems can occur when ascending to high altitude. The problems can
range from uncomfortable symptoms to life threatening conditions. The occurrence of these problems varies with the rate of ascent, elevation gained and individual susceptibility to high altitude.
Acute Mountain Sickness
• Possibly due to hypoxia (lack of oxygen).
• Symptoms occur 12-24 hrs after ascent.
• Symptoms decrease around the third day.
Mild Symptoms Moderate / Severe Symptoms
• Headache not relieved by analgesics.
• Loss of muscular coordination (cannot walk a straight line).
Treatment (Mild)
• Do not ascend until symptoms go away!
Treatment (Moderate / Severe) High Altitude Cerebral Edema
• Results from swelling of the brain due to fluid leakage.
• Generally occurs after 5 to 7 days at high altitude.
• Serious illness that could lead to death if unrecognized and untreated.
Symptoms
• Decreased mental status (lethargy, confusion).
The Diagnosis of Severe AMS vs. HACE Is Difficult. Always Assume the Worst. Treatment High Altitude Pulmonary Edema
• Results from fluid leakage into the lungs.
• Oxygen transfer from the lungs to the blood is impaired.
• Not caused by heart failure or pneumonia.
• Severe illness that could lead to death if unrecognized and untreated.
Symptoms
• Productive cough with frothy pink tinged fluid.
• Gurgling/crackling noise heard in the chest during breathing (often called “Rales”).
Treatment High Altitude Medications and Treatment
• The medications listed in the following pages are used for the prevention and/or
• These medications as well as a Gamow bag are provided by the medical facilities in
Antarctica and are carried by your camp medical provider.
• If you have any concerns or questions, you should discuss all of these medications with
your medical provider before you deploy.
Diamox(acetazolamide)
• Diamox is the drug of choice for prevention of AMS. It speeds acclimatization and may
help to avoid the development of illness if given early. It is a carbonic anhydrase (CA)
inhibitor, slowing the hydration of carbon dioxide. By inhibiting renal carbonic anhydrase Diamox reduces the reabsorption of bicarbonate and sodium, causing bicarbonate diuresis and metabolic acidosis within hours of ingestion. This does a few things: Rapidly enhances ventilatory acclimatization and maintains oxygenation during sleep. It prevents periods of extreme hypoxia. Because of its diuretic action it also counteracts the fluid retention of AMS.
• Dose: 125-250 mg the night before ascent, followed by 125-250 mg twice a day during
ascent and for 3-4 days after reaching altitude.
Diamox Side Effects
• *Numbness/tingling of fingertips and around mouth.
• *Less Commonly nausea, drowsiness, impotence, myopia. • Diamox allows you to taste carbon dioxide, ruining the flavor of carbonated beverages.
Diamox contraindications
• Consult with your medical provider about possible interactions with any medications you
Dexamethasone (Decadron)
• Dexamethasone is indicated for the treatment of HACE. It is a steroid that is effective in
reducing edema in the brain. It should be used in conjunction with descent or use of gamow bag.
• Dose: 4 mg (tablet or injection) every 6 hours until evacuated to a safe elevation.
Nifedipine (procardia,adalat)
• Nifedipine is a calcium channel blocker that aids in the treatment of HAPE. It is effective
in reducing pulmonary vascular resistance and pulmonary artery pressure. It should be used in conjunction with oxygen and descent.
• DOSE: 10 mg every 4 hours, titrate to response or,
• 10 mg once, then 30 mg sustained release tablet every 12 to 24 hours
The Gamow bag
• The Gamow bag is a portable hyperbaric chamber.
• It is used when the patient is unable to descend or is awaiting transport to a lower
• It simulates descent to lower altitudes.
• By increasing pressure inside the bag, oxygen regains its “pushing power” allowing
oxygen to be pushed into the bloodstream.
Preparing For Altitude Preparing before deployment
• Talk to your medical provider! Let them know you will be working at altitude. Discuss any
concerns you have or anything you do not understand about working at altitude.
• Inform your medical provider if you have ever experienced altitude illness in the past.
• It is especially important to talk to your medical provider if you take ANY medications on
a regular basis. Also, you may be taking Diamox so make sure there are no adverse interactions of Diamox with your medications. You should also discuss any pre-existing medical conditions that could be affected by going to altitude.
• As already mentioned, you need to bring your own supply of your regular medications.
The medical facilities on the ice do not have a large enough inventory to supply you for a whole season.
• Use the references at the end of this presentation to research more info about altitude.
Preparing for Departure to Your Field Camp
• Begin to hydrate NOW. Start to increase your water intake to at least 4 to 5 quarts a day.
Sip a quart an hour. Trying to drink a lot at one time does not work. Drink slowly and space it out over time.
• Try to rest and get some good quality sleep while here in the “thick” air. This can be
difficult to do while preparing for a big project, but try to relax at the end of the day.
• Even harder to do, decrease caffeine and avoid alcohol 2 days prior to departure.
• The night before departure begin to take Diamox (acetazolamide). The dose is 125 to
250 mg. Take one tablet the night before departure and continue to take 1 tablet twice a day for 4 days. This will begin the acclimatization process before you depart. The medical department will dispense Diamox to you. No appointment is necessary, just walk in during clinic hours.
• Mentally prepare yourself. Understand that the first two days after arrival at camp you
will be relaxing! No work is to be done. This will give your body a chance to acclimatize to the altitude.
Arrival At Altitude
• BREATHE! Even though this will occur naturally, you need to remember to breathe.
There is less available oxygen at altitude so you need to take advantage of every breath you take.
• REST. You need to let the altitude get used to you! Read a good book, play cards. Think
about what you need to do after the first few days, but NO heavy exertion!
• LIGHT EXERCISE. It is better to get up every once in a while and move around rather
than just lay in bed. Stretch and do light exercises. Shoveling snow is NOT light exercise!
• Continue to take Diamox twice a day for the first few days. The medical provider at your
camp will evaluate your progress adapting to altitude after that time period.
• Again, DECREASE CAFFEINE AND AVOID ALCOHOL during the acclimatization
period. Alcohol impedes ventilatory acclimatization.
• You may have a medical care provider at your camp who is trained in attitude illness. If
you have any questions or concerns please talk to them.
• If you have any worsening of symptoms or increasing headache, see the medical
provider ASAP! The more quickly you are assessed and treated, the less likely you will develop HAPE or HACE.
• It is also very important to talk to the medical provider before taking ANY medication. In
particular, narcotics and sleep medications should NOT be taken while acclimatizing as they are respiratory depressants and may kick you into AMS.
A reminder of normal things that happen at altitude.
• Hyperventilation and shortness of breath.
• Waking up many times during the night (mainly to pee!).
• Periodic breathing at night while you sleep.
• All of these things are the body’s way of adapting to the high altitude and they are all
normal! Again, if any of these symptoms are increasing or you have a headache that is increasing in severity, see the medial provider right away, even in the middle of the night!
No Worries!!
The occurrence of altitude related illnesses are LOW in Antarctica. Most participants in the USAP have no problem acclimatizing to altitude and do fine. Following the recommendations offered in this presentation will greatly increase your chances of avoiding an altitude related illness and will help your body adjust to the high altitude environment. Enjoy and be safe up there! Pre-Deployment Check List
• Inform your medical provider you will be working at high altitude.
• Discuss concerns regarding any pre-existing medical illnesses and how they may be
• Inform your medical provider if you have experienced any altitude related problems in
• Inform your provider about the option of taking Diamox to acclimatize to altitude.
• Contact your Science PI or your RPSC manager with any concerns about your
• Feel free to do further research about high altitude environments and physiology with the
Where to find more information about altitude and altitude related issues:
• Wilderness Medicine by Paul Auerbach, M.D.
• Going Higher: Oxygen, Man, and Mountains by Charles Houston
• Medicine for Mountaineering by James Wilkerson, M.D.
• Altitude Illness: Prevention & Treatment by Stephen Bezruchka, M.D.
• Many web sites exist with generous amounts of altitude related issues: use a “search”
for “altitude” to browse the many topics available.
References
• Auerbach, Paul S. Wilderness Medicine. St. Louis: Mosby, 2001
• Houston, Charles. Going Higher: Oxygen, Man, and Mountains. Seattle: Mountaineers,
• Wilkerson, James A, ed. Medicine for Mountaineering. 3rd ed. Seattle: Mountaineers,
ALTITUDE QUIZ
1. What elevation is considered “high” altitude?
2. In Polar regions, inadequate oxygen in the bloodstream occurs at lower elevations. a)
3. The Process by which your body adjusts and adapts to the decrease in oxygen available to the tissues is called:
4. The body acclimatizes to altitude by altering which processes?
5. Everyone acclimatizes at the same rate. a)
6. Normal body responses to altitude include all of the following except: a)
7. Mild symptoms of AMS include a headache with which of the following: a)
8. High Altitude Cerebral Edema is a serious illness that must be treated immediately. a)
9. Signs/Symptoms of High Altitude Pulmonary Edema include:
b) Productive cough with signs of fluid in lungs
c) Increase heart rate and respiratory rate
10. Initial treatment for all altitude illnesses include:
11. Prior to departing for altitude you should:
a) Stay up all night so you can sleep enroute
b) Rest, Hydrate and avoid alcohol, tobacco and depressant medications
c) Sleep on oxygen the night before departure
12. The altitude medication Diamox is available at McMurdo Medical clinic: a)
13. After arriving at altitude you should:
a) Work as hard as you can to get settled in
b) Do rigorous exercise to get used to the altitude
c) Rest, Hydrate, light exercise and avoid tobacco, alcohol and depressant
QUIZ ANSWER KEY
1. C 2. A 3. C 4. E 5. B 6. B 7. D 8. A 9. D 10. E 11. B 12. A 13. C
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