Category Archives: Mountaineering

Already an extreme sport, mountaineering at high altitudes adds exponential risk! Know before you go!

WMS Blog Entry No. 5: Advances in Frostbite, a Synopsis of Dr. Peter Hackett’s Lecture

Frostbite is an injury caused by freezing of the skin and underlying tissue. The main pathophysiology of frostbite is ischemia. Basically, where there is blood flow there is heat and where there is no blood flow there is no heat to that area. The vasoconstriction and loss of blood flow to the skin predispose the skin to becoming frozen. Heat transfer depends on blood flow and blood flow depends on sympathetic nerve tone. In our extremities, there are only nerves that cause vasoconstriction. Exposure to cold or a drop in the body’s core temperature can induce vasoconstriction from these sympathetic nerves in which decreases the amount of blood flow to the extremities to keep the central aspect of the body warm and central organs well-perfused to help to maintain the body’s core temperature.

Frostbite usually occurs in the apical areas of the skin also called glabrous, which is Latin for smooth because these areas have no hair. These areas include the face, palmar surface of the hand, and the plantar surface of the foot. These areas of the skin are rich in arteriovenous anastomoses, which are low-resistance connections between the small arteries and small veins that supply the peripheral blood flow in the apical regions of the skin. These anastomoses allow the blood to flow into the venous plexus of the skin without passing through capillaries, and play a major role in temperature regulation.

Causative factors of frostbite include inadequate insulation, circulatory compromise, dehydration, moisture, trauma, and immobility. All of these factors in combination can result in frostbite.

The behavioral risk factors include mental illness, alcohol/drug use, fear, apathy, and anxiety. All of these risk factors can contribute to frostbite, generally, from poor self-care.

Frostbite is said to kill twice during its two phases that occur. The first phase is the frozen phase in which ice crystals form in the intracellular compartment at about 29 degrees Fahrenheit. These ice crystals will suck the fluid out of the endothelial cells and become enlarged causing the endothelial cells to lyse from dehydration and interrupt microcirculation. The second phase is the rewarming phase in which the skin thaws and is at risk for microthrombi production and necrosis due to prolonged injury to those endothelial cells.

The usual phase at which we see frostbite in a clinical setting is after thawing, in which the skin looks flushed pink, red, with the appearance of blebs that form one hour to twenty-four hours after thawing. These blebs can rupture spontaneously in 4-10 days and shortly after, a cast-like eschar forms. Then the eschar usually sheds in 21-30 days.

Deep Frostbite

Frostbite is classified based on the depth of tissue damage, from superficial with no tissue damage being mild and deep tissue damage including muscle, bone, or tendon being classified as severe frostbite. The mildest form of frostbite is called frostnip. Frostnip is freezing of the skin but there is no actual freezing injury and doesn’t cause permanent skin damage.

Stages of Frostbite

What can you do in the field for Frostbite?

It is important to provide supportive care with IV or PO hydration to prevent dehydration. If the affected area is frozen with no imminent rescue, it is recommended to thaw the area with warm water and try to avoid refreezing. You can give NSAIDs, such as Ibuprofen, 400 mg every 8 hours, or ketorolac 30 mg IV. If the person is at altitude and their oxygen saturation is low you can provide oxygen. However, the individual must be taken to the nearest hospital for further treatment, especially in cases of severe frostbite.

New research studies have been exploring the use of thrombolytics in the treatment of frostbite. Many of the research studies have shown that IV TPA or iloprost may be of benefit to administer in a hospital setting. However, iloprost is not approved for IV use in the United States and other prostacyclins have not been studied for the use of frostbite as of yet. There are current literature and guidelines that have been published for the prevention and treatment of frostbite, however, more research is needed to further support standardized treatment of all patients with frostbite with thrombolytic therapy. Hopefully, these new studies will encourage more research into using thrombolytics and prostacyclins for frostbite.

In the meantime, it would be best to stay warm to prevent frostbite. Tips to help in frostbite prevention include:

  • Limit time you’re outdoors in cold, wet, or windy weather. Pay attention to weather forecasts and wind chill readings. In very cold, windy weather, exposed skin can develop frostbite in a matter of minutes.
  • Dress in several layers of loose, warm clothing. Air trapped between the layers of clothing acts as insulation against the cold. Wear windproof and waterproof outer garments to protect against wind, snow, and rain. Choose undergarments that wick moisture away from your skin. Change out of wet clothing — particularly gloves, hats, and socks — as soon as possible.
  • Wear a hat or headband that fully covers your ears. Heavy woolen or windproof materials make the best headwear for cold protection.
  • Wear socks and sock liners that fit well, provide insulation, and avoid moisture. You might also try hand and foot warmers. Be sure the foot warmers don’t make your boots too tight, restricting blood flow.
  • Watch for signs of frostbite. Early signs of frostbite include red or pale skin, prickling, and numbness.
  • Eat well-balanced meals and stay hydrated. Doing this even before you go out in the cold will help you stay warm.

Lauren Pincomb Apodaca is a second-year Physician Assistant student in the Red Rocks Community College Physician Assistant Program. Originally from Las Cruces, New Mexico, she graduated from New Mexico State University with a Bachelor of Science in Biochemistry and a Bachelor of Art in Chemistry. After obtaining her undergraduate degrees, she was accepted as a Ph.D. fellow in Pharmacology at the University of Minnesota where she conducted research in a biomedical laboratory doing cancer research. She then realized that she wanted to make a difference in people’s lives through hands-on experience rather than working in a laboratory. She went back to New Mexico and received her certification as a nursing assistant and started from the ground up to reach her ultimate goal of being a Physician Assistant. She has enjoyed living in Colorado and the many outdoor activities that Colorado has to offer. Her favorite are kayaking, fishing, and hiking. She is looking forward to graduating soon.

References:

Hill, C. (2017, December 22). Cutaneous Circulation – Arteriovenous Anastomoses. Retrieved September 27, 2020, from https://teachmephysiology.com/cardiovascular-system/special-circulations/cutaneous-circulation/

Frostbite. (2019, March 20). Retrieved September 27, 2020, from https://www.mayoclinic.org/diseases-conditions/frostbite/symptoms-causes/syc-20372656

WMS Blog Entry No. 4, Part I: Tick Bite Prevention and Proper Removal

Ticks are blood feeding parasites. Ticks are known as vectors because they can transmit different pathogens responsible for several diseases including Colorado Tick Fever, Rocky Mountain Spotted Fever (RMSF), Tularemia and relapsing fever. While there are 27 species of ticks in Colorado, almost all human encounters w/ ticks in Colorado involve the Rocky Mountain wood tick, a tick that only lives in the western U.S. and southern Canada at elevations between 4,000 and 10,000 feet. Another highly prevalent tick is the brown dog tick which is specific to dogs.

Before you go out!

DO:

  • Wear protective clothing! Wearing long sleeved shirts, long pants tucked into your socks and close toed shoes can keep ticks from getting onto your skin, as ticks are usually acquired while brushing against low vegetation.
    • wear light colored clothing, as this makes it easier to find ticks that have been picked up
    • Treat clothing w/ permethrin as this can help kill or repel ticks for days to weeks! Do not apply directly to skin.
  • Use Tick repellent. This includes the well-known DEET along with picaridin, IR3535 and oil of lemon eucalyptus
    • Repellent can be applied either directly to skin or to clothing, AND is most effective if applied to the lower body that is likely to come in contact with ticks first!
    • If applying repellents to skin:
      • DO NOT use high concentration formulas on children (DEET concentration > 30)
      • AVOID applying repellents to your hands or other areas that may come in contact with your mouth
      • DO NOT put repellent on wounds
      • ALWAYS wash skin that has had repellent on it.
  • Remember: Dogs can get ticks too! Don’t forget to consult your veterinarian about how to protect your furry friends against ticks.

When you go out: DO NOT assume that you won’t get bit.

  • Avoid tick habitat
    • Ticks are most active in spring and early summer and are concentrated where animal hosts most commonly travel, including areas of brush along field and woodland edges or commonly traveled animal host paths though grassy areas.
      • DO try to avoid exposure in these areas by staying in the center of marked trails when hiking to avoid brushing vegetation that ticks may be perched on waiting for you!
    • If possible, avoid these sites during tick season.
    • If you live in known tick territory, you may even get a tick bite in your own backyard! Decrease this risk by creating a tick-free zone around your house by keeping your lawn mowed, eliminating rodent habitats (wood or rock piles) around your house, and placing wood chips between your lawn and tall grasses or woods.

After coming back inside

  • Perform a tick check which includes botha visual and physical inspection of your entire body, as well as your gear and pets. Because ticks take several hours to settle and begin feeding, you have time to detect and remove them. You tend to not feel ticks because their saliva has histamine suppression and analgesic effects. Ticks like warm, moist and dark areas but can latch anywhere.
    • Examine your scalp, ears, underarms, in and around the belly button, around the waist, groin/pubic area, buttocks and behind your knees.
    • If camping, perform tick checks daily on humans AND pets, making sure to examine children at least twice daily. Again, pay special attention to the head and neck and don’t forget to check clothing for crawling ticks.
    • Shower and wash your clothes after returning home from the outdoors.

If you or a family member get bit by a tick: DO NOT PANIC, and DO NOT immediately rush to the emergency room! If the tick has been attached for less than a day, the chance of the tick transmitting one of these diseases is low. Removing ticks can be tricky, as they use their mouthparts to firmly attach to the skin.

Best method for tick removal -> remove as quickly as possible!

1. Grasp the tick with fine tipped tweezers as close to the skin as possible. If tweezers are not available, use a rubber gloved hand or place tissue or thin plastic over the tick before removing it to avoid possible transmission of disease.

2. Pull tick SLOWLY and with STEADY PRESSURE STRAIGHT away from the skin

  • DO NOT:
    • Crush, puncture, twist or jerk the tick as you remove it. This may increase risk of the tick regurgitating infected body fluids into the skin or leaving mouthparts in skin

3. After the tick is removed, disinfectant the attachment site on skin and WASH YOUR HANDS. Dispose of the live tick by placing in a sealed bag/container and submersing it in alcohol, then wrapping it tightly and crushing it in duct tape, OR flushing it down the toilet.

  • DO NOT:
    • crush the tick in your fingers
    • try to suffocate the tick still on the person by covering it with petroleum jelly OR touching it with a hot match to suffocate -> these methods can cause the tick to burst and INCREASE time the tick is attached, as well as making the tick more difficult to grasp

Remember: the goal is to remove the tick quickly from the host as opposed to waiting for it to detach on its own.

If you remove the tick and are worried, you can always put the tick in a sealed container with alcohol and bring the dead tick to your medical provider.

If you develop a rash or flu-like symptoms (fever, fatigue, body aches, headache) within several weeks of removing tick, see your medical provider and tell him/her about the recent tick bite, when it occurred and where you acquired the tick.

Remember: These diseases are very treatable if caught early enough!

Graphic taken from https://www.cdc.gov/ticks/pdfs/FS_TickBite-508.pdf

Stay tuned for next month’s explanation of the tick life cycle and tick-borne diseases in the high country!

References

1. Colorado Tick and Tick Born Diseases fact sheet. https://extension.colostate.edu/topic-areas/insects/colorado-ticks-and-tick-borne-diseases-5-593/ Accessed on 8/8/20

2. Peterson J., Robinson Howe. P. Lyme Disease: An Uptick in Cases for 2017. Wilderness Medicine Magazine: https://www.wms.org/magazine/1213/Lyme-Disease. Accessed 8/8/20

3. Do’s and Don’t’s of Tick Time: https://awls.org/wilderness-medicine-case-studies/dos-and-donts-of-tick-time/ Accessed 8/8/20

Laurie Pinkerton is a 3rd year Physician Assistant Student studying at Drexel University in Philadelphia, PA. Originally from Northern, VA, she graduated from the University of Mary Washington in Fredericksburg, VA with a degree in Biology in 2014. She moved to Keystone to live that ski life and stayed for 2 years, working as a pharmacy tech at Prescription Alternatives and as a medical assistant at Summit Cardiology. Prior to starting PA school, she moved to Idaho where she learned about organic farming and alternative medicine.  She has loved every second of being back in Summit County and learning here at Ebert Family Practice. She looks forward to practicing Integrative Medicine in the near future.

WMS Blog Entry No. 3: Pre-acclimatization, A Synopsis of Dr. Peter Hackett’s Lecture

What is pre-acclimatization? It is a process of adjusting to a new climate, usually higher elevation, reducing hypoxemia in high altitude settings in turn saving time, money, and most importantly, reducing altitude sickness. It can also allow for better sleep/comfort and physiological/cognitive performance at a high altitude. Acclimatization is a time-dependent process as over 5,000 genes are impacted by a large shift in elevation affecting ventilation, plasma volume, and hemoglobin mass, among other things. The whole process is not completely understood, but one key element is the hypoxic ventilatory response (HVR). HVR is activated by the aortic artery baroreceptors, as oxygen in the blood reduces it triggers an increase in respiration. This happens immediately as you ascend in altitude and maximizes at 7-14 days. Arterial oxygen increases by an increase in ventilation/saturation and also by dropping plasma volume, increasing hemoglobin concentration, and then later on, increasing overall Hgb production which in theory, overall decreases altitude sickness.

So how can you prepare yourself or pre-acclimatize?

Some of the better-known methods are spending time at higher altitudes prior to your destination, using a hyperbaric or normobaric chamber, blood doping, hypoxic exercise training, and a few pharmaceutical methods. All of these are options, but the key question is, which ones truly work?

Pre-acclimatization with actual altitude is the most useful. Generally speaking, you would pick your maximum sleeping altitude at your destination and slowly work your way towards that altitude. You pick an ascent profile which preferably would be spread over a week or more to be most useful. This pre-acclimatization should be completed no more than 1-2 weeks prior to your destination so that any pre-acclimatization gained doesn’t wane prior to your trip.

Simulated altitude is another option which includes hypoxic tents, hypoxic rooms/homes, hypoxic exercise chambers, and hypoxic masks. Out of these four, hypoxic tents or hypoxic rooms/homes, where exposure is over a long duration, are by far the most effective. Hypoxic masks and exercise chambers are not very effective as their short duration does not give the body enough time to make the proper adjustments and although might be beneficial in respiratory muscle training/performance, do little in the way of pre-acclimatizing your body. Studies show more benefit from hypobaric hypoxia training vs normobaric hypoxia training but keep in mind studies are very limited and warrant much further research. Overall, simulated altitude minimum requirements look to be somewhere in the range of 1 week of exposure, 7 hours per day, and a minimum effective altitude of 2200-2500 m and being no more than 1500-2000 m below your target sleeping altitude. Shorter term protocols can attenuate altitude sickness but not the incidence some studies suggest. As to why hypobaric methods are more effective than normobaric methods, no one really knows yet and more research is needed.

Changing your living destination to something at a much higher elevation and exposure over years or moderate altitude residence (MAR), is the most effective method according to some studies, but this is far from feasible for most. There are studies to show epigenetic changes for those who relocate to higher elevations for long periods and these appear to be much less than those who have genetically adapted to higher elevation over generations but still more effective than the previous mentioned short-term options.

Hikers often camp at the Angel of Shavano campground before ascending Mt. Shavano, one of Colorado’s famed fourteeners.

Oxygen saturation is maximal at 11 days of exposure to a specific elevation. Diamox (acetazolamide) increases ventilation and can help with acclimatization but there isn’t much data on how using this pharmaceutical compares to other methods mentioned. World-renowned high altitude expert and pioneerDr. Peter Hackett theorizes that it may fall just short of MAR, but again, more research is needed. Short-term altitude exposure shows benefits at 7 days but a longer exposure such as 15 days has been shown to be much more beneficial.

Blood doping with EPO can be somewhat effective over a 4+ week treatment and can potentially decrease AMS and potentially increase exercise performance but the data is limited and conflicting on this. Also, it appears that it is only effective up to 4,300 m but not beyond that as arterial oxygen content is not the determining factor for sleep and cognition performance at high altitudes but rather oxygen delivery which is affected by hematocrit and viscosity of blood.

Hypoxia inducible factor (HIF) is a regulatory factor in cells that respond to a reduction in oxygen, causing changes in about 5000 different genes to help the body adjust to meet oxygen requirements. It is suggested that we could pharmaceutically activate this factor prior to destination in order to acclimatize the patient allowing for less complications and better results at higher elevations. Currently there are some drugs in trials but nothing specifically FDA approved.

Overall, data and studies are limited but the most effective current pre-acclimatization method is long-term altitude training (real or simulated). If possible, plan your ascent trip to be slow and steady to obtain best results with the least amount of complication.

Joel Miller is currently preparing to graduate from Red Rocks Community College’s reputable Physician Assistant program this Fall. He has been a resident of Colorado for four years where he has immensely enjoyed the outdoors camping, fishing, hiking, hunting, and exploring Colorado’s wide variety of breweries.

WMS Blog Entry No. 2: Long Distance Backpacking, the Wisdom of Dr. Sue Spano

Graduate of Temple University School of Medicine, Director of Wilderness Medicine Fellowship at University of California San Francisco Fresno Department of Emergency Medicine, Sue Spano, MD, FACEP, FAWM presented twice this year at the Wilderness Medicine Society’s annual (virtual) conference. Boasting the experience of about a thousand miles of the Pacific Coast Trail in Oregon and California and other recreational excursions, she shared a wealth of advice and personal recommendations for long distance backpacking.

To put it all into perspective, she referenced the Pacific Coast Trail (PCT), John Muir Trail (JMT) and the Appalachian Trail, each covering 2650 mi, 211 mi, and 2200 mi respectively. These are trips that last, easily, months. The general time frame for many of her recommendations is about five to six months.

Not surprisingly, the issue of weight comes up frequently for travelers. There are a number of studies done on this, from body mass index to base pack weight, and every ounce counts. While fitness level does not directly correlate to the incidence of injury, increase in BMI does correlate directly to increased risk of illness, injury, and trail evacuation. It is notable, however, that in a poll, about 2/3 of those hiking the PCT and well above those on the JMT trained before embarking on the trail, and most of them considered themselves to be “above average” in their level of fitness (7 or 8 on a scale of 1 to 10).

Although Dr. Spano does recommend carrying backups of three things — lighters, water treatment systems, and first aid — when it comes to base weight, there are several items that may be worth a little more investment for fewer ounces. Right off the bat: trail runners over boots. The mere difference in ounces becomes significant after so many miles, and the flexibility of softer shoes helps prevent a lot of discomfort (blisters, for example). She also notes that trail runners are more breathable and dry more quickly, sharing that she doesn’t typically bother to take them off to cross water or in snow as they will dry right on your feet along with your socks. It would be interesting to hear accounts of the footwear of preference on the Colorado Trail, where elevations are frequently higher and there may likely be more snow in general.

In another poll, 21.8 lbs was the base weight carried by packers, most of whom would have carried less in hindsight. This can be achieved by investing in lighter backpacks, tents, hiking poles, sleeping bags and sleeping pads, specifically. ULA Equipment out of Logan Utah makes an ultra-light pack that Dr. Spano prefers, “no conflict of interest”, just her personal favorite.

Skip the toothpaste, Spano urges. It doesn’t actually clean your teeth, so you might as well just brush with water.

Something else we’re seeing more and more of on distance excursions is tents that incorporate hiking poles as tent poles. Hiking poles themselves are recommended more and more as well, as they distribute more weight away from your legs.

Toilet paper must be packed out with you on much of the trail these days! Thus, the rise of the “backcountry bidet”, which you can make yourself by poking holes in the cap of a plastic liter water bottle. “You come out feeling like you had a full shower,” Spano testifies, and the water you use does not have to be filtered or potable.

Water! Know where your next water source will be. “Camel up at water sources … When you get to a water source, spend some real quality time there soaking your feet, cleaning your bandana, drinking as much water as you possibly feel like you want. Because the only time that your water is going to be ice cold is when you’re at that stream. Anything that you carry with is going to get really warm … Your easiest way to carry water is in your belly.”

When it comes to long distance backpacking, one of the finest pieces of advice Dr. Spano offers is that you should always be upgrading and optimizing your strategy:

“A person who hasn’t changed their backpacking practices in the last 10 years is not a person that I would really want to backpack with. A person who practices medicine the same way they did 10 years ago is not someone I want to practice medicine with. You should always be improving your gear, improving your behaviors, improving the way you approach the same challenge so that you’re a better backpacker as a result.”

Her hour-and-a-half practicum is available on the Wilderness Medicine Society website.

robert-ebert-santos

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

WMS Blog entry No. 1: The Rule of 3’s and other pearls from the annual Wilderness Medical Society Conference 2020

Over 800 participants from 25 countries joined the virtual conference this year which included Dr. Chris’ poster presentation on growth at altitude. Over the next several months we will extract the most relevant information to publish in our blog, starting with:

The Rule of 3’s

You can survive 3 minutes without oxygen

                              3 hours without shelter in a harsh environment

                              3 days without water

                              3 weeks without food

Dr. Christine Ebert-Santos presents her research on growth in children at high altitude, “Colorado Kids are Smaller.”

We will be sharing some of the science, experience and wisdom from these meetings addressing how to survive. For example, Dr. Peter Hackett of the Hypoxia Institute reviewed studies on how to acclimatize before travel or competition in a low oxygen environment.

Susanne Spano, an emergency room doctor and long distance backpacker discusses gear, how to build an emergency shelter in the wild, and when it is OK to drink from that refreshing mountain stream.

Michael Caudell presenting on plant toxicity.

Michael Caudill, MD shares what NOT to eat when you are stranded in the wilderness in his lecture on toxic plants.

Presentations included studies of blood pressure in people traveling from sea level to high altitude, drones delivering water to stranded hikers, an astronaut describing life and work at 400,000 m, what is the best hydration for ultra athletes, how ticks can cause meat allergy, and, as always, the many uses for duct tape.

Duct tape for survival.

We will also update you on the treatment of frostbite as well as a discussion about “Climate change and human health.”

Sign up for our regular blog updates so you can be updated on wilderness and mountain medicine!

Backcountry & Avalanche Safety: Insight from Backcountry Athlete Dan Beerman

Another Spring season in Colorado. The ski resorts have closed early per the COVID-19 protocol, along with most other establishments. Even on the normal schedule, most ski resorts would have been closed for the season by now, bringing more people to the backcountry. But this year seems to have seen an upswing in backcountry activity, where many people are going to stay active while limiting exposure to others. Just over a week ago, a team of 20 search and rescue volunteers rescued a 26-year-old man who had fallen hiking on steep terrain around St. Mary’s Glacier, Colorado. Last year, a total of 10 snowmobilers were killed in the backcountry in avalanche slides. Only one was wearing a beacon.

Backcountry and Avalanche Safety resources, thankfully, are growing more plentiful and accessible, and last winter, we published an article on the basics. Earlier this winter, I spoke with backcountry athlete and web development colleague Dan Beerman, whose experience in the backcountry really broadened as a backpacking guide in New Mexico during the summers 12 years ago, followed by a position as a climbing instructor.

Dan Beerman on the Pacific Crest Trail

When I was a backpacking guide, I was on the search and rescue if I didn’t have a crew … We had a radio, so we were the point of contact for finding and doing extraction. That’s when I learned the most and was exposed to the most. I took my Wilderness First Responder course in 2014, and that was through the Wilderness Medical Institute.

Dan’s also a fellow hut tripper, and we’ve been talking about doing one together (when we’re on the other side of the current pandemic). He’s spent the last two New Year’s in huts, backcountry skiing or snowshoeing tours. This past year, he skied Buffalo Mountain’s Silver Couloir, in the Gore Range, and made an attempt at a couloir on Mt. Torrey’s. And there have got to be some good “couloir” puns out there.

Beerman on Buffalo, Summit County, CO.

I have aspirations to do the Colorado trail quickly, but I don’t know if I wanna do that in a competitive way or just recreationally backpack it. It’s hard to balance summer objectives, or climbing objectives vs. winter backcountry goals vs. alpine mountaineering objectives.

And he makes a great point:

In Colorado, your recreation is so close to becoming high-consequence all of the time! If the weather changes from the trailhead, that could be a really big problem.

I’m familiar. Nothing really teaches you as much or as quickly as getting caught in Colorado’s extreme weather patterns.

Avalanche Safety

Dan took an Avalanche Awareness and Safety class through Colorado Mountain School, held up in Rocky Mountain National Park over two field days after two nights of class in Boulder. His main takeaway:

Check an avalanche conditions snow report daily. Observing the snowpack over the season is going to make your confidence on the day of your excursion a lot higher. I’d had no context for why avalanches were happening, where and why it’s dangerous. Having that lens through which to view weather events in terms of avalanche conditions is so valuable. It’s an intuitive thing about paying attention to the weather.

This is my first season getting out at Copper, for example, and they all have that double-black diamond terrain in the back bowls that are labeled ‘EX’ on it. There’s a sign that says, ‘Ski with a partner,’ and I just thought, ‘Oh, shit, that sign should probably be much bigger!’

Beacon, shovel, probe are the mandatory avalanche terrain items — you’re putting other people at risk if you don’t have [them], because even if you observe a slide, you can’t do anything about it. Additionally, if you don’t have a beacon in a slide, others can’t find you. You’re not contributing to a rescue, nor can you be rescued. In Colorado, there’s an increasing awareness for that. I typically will bring that with me all the time, it’s just always in my ski bag. Having some snacks, having some water, those are the kinds of things: you should never not have them.

Beerman in his beacon.

Training

I’ll take the goals of the expedition and plan accordingly. If I’m doing a ski trip, I’ll wanna get out and do hikes with weight or runs where I’m doing elevation several times. I like to do six weeks out, of four weeks of training and two weeks of tapering down.

Nutrition

I tend to be in a constant attempt to gain weight. On the Pacific Crest Trail I tried to gain weight prior, eating a lot of fatty foods, that kind of thing. Jonathan and I came up with this metric: calorie-per-dollar-per-ounce. Lightweight food that’s affordable, easy to ingest, easy to prepare, and you aren’t having to burn a lot to carry that with you to the backcountry.

[On the trail], peanut butter is always a winner. Olive oil is one of the highest calorie-per-ounce [food]. I have literally drank it before, but just add it to everything. I do eat a lot of standard trailmix, it’s easy and accessible. I’m a big fan of pumpkin seed mix or stuff with chocolate in it. I like CLIF bars. I do not like Luna bars because I’ve eaten so many of them. I can’t eat pop tarts anymore because they used to be in the meals that were issued when I was a guide. Snickers bars are a great calorie-per-dollar-per-ounce deal. I eat a Snickers bar or two before bed when I’m sleeping at altitude so my body has calories to stay warm.

I’ll make these mass-gainer complex food supplements. It’s like protein powder, but it also has carbs, like a workout and performance powder. And I would add that to water with coffee, and that would be a breakfast while hiking. There’s a lot of different kinds of powders and mixes you can add, but when you’re in calorie-burning mode, I do recommend this. If you’re hiking 20+ miles in a day or 4000+ feet of elevation in a day, you’re burning greater than 4000 calories, so you really have to eat more than you think you can.

Acclimatization

I wouldn’t say that I had HAPE (high altitude pulmonary edema) or HACE (high altitude cerebral edema) … Definitely, especially when I was younger … I would travel from 4000′ to 10,000′ in a 24-hour period. I’ve actually had search and rescues where someone was having night-terrors or hallucinations [due to HAPE or HACE]. I was a backountry professional for the Boy Scouts at a camp at 10,800′ (one of the first backcountry camps, in New Mexico). I’ve experienced dizziness, nausea, insomnia, weakness of the knees, elevated heart rate … and I’m a runner, I’m in decent shape. But you should acclimatize before setting out on a trip.

Skiing down the Silver Couloir.

One last piece of advice,

Learn the Leave No Trace principles. We live in a state where impact is so concentrated that the more that everybody knows, the more likely it will be there for the next generation.

Dan and his backpacking, backcountry cohorts keep a blog full of breathtaking landscapes and telling captions on CaptainsofUs.com.

There will be plenty of time to escape to the backcountry again after the risks of COVID-19 have subsided. The current time is a good time to start preparing mentally. Know before you go.

robert-ebert-santos

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Aconcagua: an Athlete/Medical Scientist’s Narrative in Symptoms

“Day 10: I walked for maybe an hour up to Camp 3 (19,258’/5870 m) from Camp 2 (18,200’/5547 m). I became the slowest person. I had tunnel vision. It was bad. It took a lot of willpower. I do a good job of not telling people how bad I really feel. After about a mile, I told them I had to stop, and me and Logan turned around. We had that conversation,

‘I don’t think I should go up anymore. It’s not safe for me, and it’s not safe for the group.’

Barely able to move, about an hour above Camp 2.

“The others didn’t go all the way to Camp 3, but continue on a bit more. Angela said she got a headache really bad and couldn’t see out of her right eye. I had already pretty much decided — I was devastated — after two nights and two days of not acclimating. Alejo had a stethoscope and said my left lung was crackling. We thought I might develop some really serious pulmonary edema.”

Keshari Thakali, PhD is an Assistant Professor in the Department of Pediatrics at the University of Arkansas for Medical Sciences in Little Rock, AR. She is a cardiovascular pharmacologist by training and her research laboratory studies how maternal obesity during pregnancy programs cardiovascular disease in offspring. When not at work, you can find her mountain biking, rock climbing, hiking or paddling somewhere in The Natural State. She has a long-term career goal of merging her interests in mountaineering with studying cardiovascular adaptations at high altitude. She has climbed to some of the most extreme elevations in the Rocky Mountains, Andes and Himalayas. Last December, she flew down to Mendoza in Argentina for an ascent up Aconcagua.

Sacred in ancient and contemporary Incan culture, and the highest peak in the Americas, Aconcagua summits at 22,837′ (6960 m). Current statistics show only 30 – 40% of attempted climbs reach the top of this massive mountain in the Andes, in Principal Cordillera in the Mendoza Province of Argentina.

Sunset on Aconcagua from Base Camp.

The day following Keshari’s decision not to summit, she hiked back down to Plaza de Mulas (14,337’/4370 m) from Camp 2, carrying some of her colleague’s gear that he didn’t want to take up to the summit as he continued to ascend. Plaza de Mulas is a large base camp area with plenty of room for tents, available water, and large rocks that provide some protection from the wind as climbers take time to acclimate before continuing their ascent.

“Even though my oxygen [saturation] was low, I was functional. As you go down, everything gets better. The others continued up to Camp 3. They spent one night there, then summited the next day. It took them 12 hours.

“The day the others came back to Plaza de Mulas, I think that’s when everything hit me. I felt like a zombie. I did some bouldering and got so tired I had to sit down and catch my breath often, probably because I had been hypoxic and we were at over 14,000′.

“[The next day] we did the really long hike from Plaza de Mulas all the way to the entrance of the park. It probably took about 8 hours to walk all the way to the park entrance.

“We drove to Mendoza that night. I felt like my body was tired, but my muscles were functioning just fine. It’s hard to describe.”

They had done everything right and had taken every precaution. Each of Keshari’s colleagues boasted significant backgrounds in climbing and mountaineering, their cumulative accomplishments including Mt. Elbrus (18,510’/5642 m), Cotopaxi (19,347’/5897 m) and Denali (20,335’/6198 m), their ages 30 to 65. They weren’t initially planning to hire porters, “but they ended up carrying a lot of our stuff. In the end, it just makes sense to hire these porters to increase your chance of success.”

They gave themselves about two weeks to make the ascent and return. There was ample time for them to stop at each camp and spend time acclimatizing, including day hikes to the nearby peaks of Bonete and Mirador.

“Day 4 [we did an] acclimatization hike to Bonete (16,647’/5074 m), pretty much the same elevation of Camp 1. You look at the mountain and it looks pretty close, but … in mountaineering, you don’t do distances, you do time. Did the hike in mountaineering boots, which were heavy and clunky, but I learned how my boots actually work. You walk differently in these than a shoe with a flexible sole. The last part of the mountain is pretty rocky and it looks like you’re almost to the top, but you still have to walk an hour to the summit. It took about five hours to go up. We were walking slow, I felt fine. From the top of that mountain, looking away from Aconcagua, you can really see Chile and the Chilean Andes.”

Summit of Bonete.

All the way through their first week of climbing, including a day of resting and eating after their hike up Bonete, Keshari was feeling fine.

“Day 8, we made the push to Camp 2 (18,200’/5547 m). None of these hikes made me tired. I was plenty trained. We were carrying packs, but they were still pretty light, packed with stuff for the day. We spent the night at Camp 2, took oxygen mostly at night. [My] first reading at Camp 2 was low. We were at over 18,000′. I thought maybe I’ll just go to sleep and it’ll get better.

Looking down on Camp 2 covered in snow.

“Day 9 was a rest day at Camp 2 because the weather was really bad. All I did was sleep that day. If you’re gonna go to Camp 3, that means you’re gonna do a summit push the next day, because Camp 3 is so high. You’re just struggling to stay healthy. I felt really bad in the tent, but if I went outside to pee or walk around, I felt better. My pulse ox was still pretty low that day. That night, a snow storm blew in and it snowed a lot.” And it was the following day of their ascent to Camp 3 that Keshari made the decision not to summit.

Since returning from her expedition, she’s reflected on some other variables. “I swear I was hyponatremic (an abnormally low concentration of sodium in the blood). We went through four liters of water a day with no salt in the food. I was having these crazy cramps in my abs and my lats and places I don’t typically get them. To me, that has to do with electrolyte imbalance. Next time, I’m taking electrolyte tablets, not just stuff to mix in my water.

“I’m not very structured in my diet. In general I eat pretty clean, but I don’t count calories. I eat vegetables, but I also hate going grocery shopping. I feel like I eat a pretty balanced diet. If I buy meat, I’ll buy a pack of chicken and that’s my meat for a week or two.

“On the mountain, in general, I felt like they fed us way more fiber. In Argentina, they eat a lot of meat. They’re meat-eaters. They didn’t feed us steak on the mountain, but … at Base Camp, I felt like they were overfeeding us. We had pork chops one night, but on the mountain, I felt like it was mainly lentils and noodles. Even though you’re burning calories, how your body absorbs them is different. They really try to limit your salt intake because they’re concerned about having too high blood pressure. At Base Camp, breakfast was always scrambled eggs with bacon and toast. Lunch and dinner were always three course meals starting with a veggie broth soup. They fed us like kings … I brought Clif blocks with caffeine in them for hiking snacks, Lara bars.”

I ask about her main takeaway from it all:

“I think I need more time to acclimate. I don’t know how much more time, but maybe more time at about 16,000′. Maybe take Diamox. Someone suggested I should have been on an inhaled steroid, especially because my asthma is worse in the cold. If I were to go next time, I would want a couple more days at 15,000 – 16,000′. Maybe the Diamox is something I would need to use next time.

“The nerd in me wants to measure pulmonary wedge pressures (via very invasive catheters; you could go through the jugular), nothing practical,” she laughs. “The pulse oximeter is the easiest tool.”

One last thing she’d do differently? One of her colleagues bought a hypoxic generating system from Hypoxico, “which I think puts CO2 back into your system; sleeping high, training low. That might have been the best thing.”

Keshari went sky-diving back in Mendoza the day after returning from their descent. “I was expecting a lot of adrenaline jumping out of an airplane, but there was none. I enjoyed the freefall, but when the parachute went up, I got really nauseous. Maybe I had just been stressed for so long, there was no more adrenaline left. I was like, ‘Where’s the risk involved in this?'”

An illustrated oxy-journey.

Keshari also summited Cotopaxi earlier the same year. Read her own account here.

robert-ebert-santos

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Medicine Man: Ski Patroller & EMT Jonathan Sinclair’s Elevated Experience

“I’ve been here 25 years,” Sinclair shares with me over coffee at the Red Buffalo in Silverthorne, Colorado (9035’/2754 m). “Born and raised on the East Coast in Philadelphia.” The software company he had been working for moved him out to Colorado Springs. He hadn’t ever skied in his life until then. Shortly after, “on a whim”, he moved up to Summit County and started working on the mountain as what we used to call “Slope Watch”, the mountain staff often in yellow uniforms monitoring safe skiing and riding on the mountain. After a month, he got really bored, “and I said, ‘How do I get to be a patroller?'”

Sinclair then went to paramedic school to get qualified as an Emergency Medical Technician, then spent 19 years as an EMT and 9 years as a Medic. For the last six years, he’s worked for the ambulance service in Summit County, one of Colorado’s highest counties, with towns at above 9000′. He has also worked as a ski patroller at Copper Mountain, Keystone, and Park City (Utah). This year is the first he hasn’t been patrolling in 18 years. During the summer, he is a wildland fire medic, where he often works with crews that are shipped in from lower elevations, including sea level.

Although he’s decided to take this season off, he still maintains a very active relationship with the outdoors, travelling around the backcountry on expeditions to remote mountain cabins, and has made a recent trip to Taos, New Mexico (6969’/2124 m). He’s witnessed his share of altitude complications.

What are the most common altitude-related complications you see?

You see the families coming up to go skiing … Usually 90% of them are fine. Altitude doesn’t seem to bother them at all – they’re either healthy enough or lucky enough. They get in, they ski, they get out. But there’s that one family or that one couple that just don’t acclimatize. They don’t realize that they don’t acclimatize, and the rest of their group doesn’t realize. A couple of days go by and they think, ‘Geez, I feel awful,’ then they go ski, or do something active, and their condition is exacerbated. Or ‘Geez, I haven’t slept,’. you get that story over and over.

And you’re having this conversation on the hill as a patroller?

Or they’ve called 911 on their way [up to the mountains]. They have no idea. Just no idea. I ask them what they’d had to eat. They had a donut or a pastry or just coffee before the plane ride. I ask them when was the last time they peed. You’re trying to find the physiology of what’s happened.

I tell them, ‘You need to sit down or go back to your condo. You need liters of water. You need liters of Gatorade. No fried foods, no alcohol, no coffee. No marijuana. Let your body catch up. Wherever you’re staying, tell them you need a humidifier. Put it in every bedroom, crank it up and leave it on. You’re gonna have trouble sleeping.’

And they never wanna hear it. They never wanna take a day off, but by the time you see them, they’ve taken the day off anyway, because there’s no way they’re getting back up there!

Sinclair also expresses some frustration with the lack of resources provided by the ski industry itself:

How do you educate them? The marketing people don’t want to. Because if they have to spend a day in Denver [to acclimate], that’s one less day up here [at the ski resort]. They don’t want to publicize that [altitude sickness] can happen, that it’s common. People ask, ‘How often does this happen?’ Easily, at any resort in a day, Patrol probably sees 20 – 25 people, whether they called, they walked in, you skied by them and started talking to them. ‘You’re dehydrated. You’re at altitude. It means this …’ The resorts don’t want that many to know, otherwise, you’re gonna go to Utah or California, where it’s lower.

You get such misinformation. ‘At 5000 ft., you have 30% less oxygen.’ No, the partial pressure is less, there is still 21% O2 in the air. You just have to work harder to get the same volume. The real physiology of what’s going on is systemic. [People experiencing altitude sickness] don’t know why they feel like crap. They think it’s because they’ve been drinking too hard.

How do you mitigate their symptoms on the mountain?

We do a lot, but it’s reactive, not proactive. I hate to bash the oxygen canisters, but it’s not doing anything for you. It’s not gonna make you feel better, other than what you’re sucking up. At 10,000′, it’s questionable. We’ll be at the top of Copper [Mountain] giving them two to four liters of oxygen, then they’ll ski down and feel great.

Sinclair refers to the Summit County Stress Test, which was the first I’d heard of it:

You’re 55, you’re 40 – 50 lbs. overweight, and you come up for your daughter’s wedding. You walk over to Keystone [Ski Resort], you take the gondola over, then all of a sudden, you find out you have a heart condition. You find out whatever else you have going on. We’ve done it over and over and over. They go ski, they call us at 3 in the morning, we find out they’ve got a cardiac issue, or they’ve irritated the pulmonary embolism they’ve had for years.

I had a guy last year, at the Stube at Keystone for lunch.

Keystone’s Alpenglow Stube is a reputable restaurant that sits in the resort’s backcountry at 11,444′ (3488 m).

He had some food, alcohol, he’s having a great day. Ski patrol gets a call, ‘Hey, my husband doesn’t feel well.’ This guy looks bad, sitting on the couch, sweating profusely, and he can hardly tell what’s going on. It’s the classic presentation of an inferior heart attack.

‘I don’t have any heart conditions. I saw my cardiologist.’ You saw a cardiologist, but you don’t have any heart conditions?!

And there are a lot we don’t see. People who go home because they think they have the flu.

Have you seen any rare or surprising complications?

We see HAPE (High Altitude Pulmonary Edema) now and again. That seems to be a walk into the hospital where [their blood oxygen saturation is] at 50 – 52. We’re not in the zone to see HACE (High Altitude Cerebral Edema). We’re just not at the altitude.

HACE is more typical above more extreme elevations, above 11,000′. Colorado’s highest peaks are just above 14,000′. Most ski resorts in Colorado are below 12,000′.

I’ve only seen one HAPE case on the hill. In their 50s. You listen to their lungs, and they’re getting wonky. A guy who was reasonably fit, but you look at him and go, ‘Hm, this is bad.’ But he was responsive and talking. Then you start seeing the things like the swaying, getting focused on something else [in the distance]. One of those [situations] where you’re like, ‘Let’s get out of here.’ [We need] tons of oxygen. Again, ‘I didn’t feel good yesterday, but I decided to go skiing today.’ He was sitting at the restaurant at the top of Copper [Mountain].

People do not realize that their diabetes, their asthma, their high blood pressure, things that they commonly manage at home, are exacerbated at 9000′. By the time they realize it, they’re calling 911. At that point, your best bet is to get out of here.

What tools or instruments do you use the most as a paramedic and ski patroller?

Cardiac monitor. It’s got a pulse oximeter. [Also] simple things you ask. ‘Hey, do you know what your blood pressure is?’ I use a stethoscope all the time. Sight and sound. Are they talking to me? Are they having a conversation with me? Are they distracted by what’s happening to them? When was the last time they peed? Was it regular color? Did it smell stronger than usual?

People ask, ‘How much water do I need?’ How much water do you drink in a day? If I’m outside and I’m moving, I probably have 10 liters. If I’m on a roof laying shingles, I probably have 4 or 5 liters before lunch. It’s those little tools. You don’t even have to touch somebody.

Do you have any personal recommendations for facilitating acclimatization at altitude?

Workout, be in shape, go harder than you normally do that month before you get here. Get the cardiovascular system more efficient before you get here. If you have any kind of medical concerns, make an appointment with your doctor and say you’ll be at 10,000′ to sleep. Just ask, ‘What do I need to do?’ The day before you get on the plane, stop drinking coffee and start drinking water. Hydrate before you get here. They humidifier thing. Make sure the place you’re going has one. Find out. Go to Walmart and spend $15 to buy one.

Watch your diet. Just so your body’s not fighting to get rid of fat and crap.

When we’re getting ready for a hut trip, we are mostly vegetarian (although we do eat meat), but we ramp protein up a week prior, pushing more chicken, more red meat. We tend to eat fish normally, but there’s always at least one fish meal at the hut. We don’t do crappy food at the hut. I don’t care if I have to carry another 10 lbs. In addition to going to the gym, go for a skin, go to 11,000 – 12,000′ for a couple hours. Ramp up the altitude work.

What do you eat on the trail?

Pre-cooked sausage, usually some kind of chicken sausage. Cheese. Whole grain tortillas, and if we’re feeling spunky, some kind of hot sauce or pico [de gallo]. For me, it’s just a handful of nuts and raisins. If I feel like something else, I’ll throw in some chocolate or white chocolate. I hate the packaging, the processed foods, the bars. Somebody usually makes granola for on-the-way-out food. And I tend to carry dried fruits. Lots of peaches during Palisade peach season. I used to take a lot of jerky.

A recent topic that comes up alot in altitude research at our clinic is Aging.

I have to work harder to stay at the same place. I’m sitting here and I can feel my right knee. I was at a 15″ [of snow] day in Taos, and I caught something [skiing]. It’s been weeks, and it’s not weak or anything, but I just know. It takes longer. I find I need more sleep. I was a 4 or 5 hour a day guy for a long time. Now I’m at 7. The days I get 8 are awesome. Luckily enough, I’m still healthy, fit. If I’m up at night, it doesn’t shatter my day. Haven’t slept on oxygen yet. Don’t want to find out.

He laughs.

As I get older, I’m adding more supplements: fish oil, glucosamine, glutine (for eye health). My eyes are bad anyway, and I’m constantly standing outside against a big, white mirror (the snow). And I’m cautious of the bill of a hat vs. a full-on brim during the summer. Other than my face, everything’s covered during the winter. The color of the bill on your hat can be way more reflective. A black bill will cut the reflection. Little things.

I’ve rounded out my workouts. They’re more whole-body. I concentrate on cardio. I’m conscious that I’m not as flexible as I was. I’d like to say we’re regularly going to yoga, but at least we’re going.

The gauge for me is you go on a hut trip with our friends in the middle-age category, but we’ll take some younger folks [too]. I kinda monitor who’s doing what – chopping firewood, who’s sitting more than who. It’s not out of pride. I need to realize.

I’m colder. You start to notice. It’s not that your feet are cold, it’s that your calves are cold. I succumbed to boot heaters a few years ago.

Year after year, in every season, visitors from all over the state and all over the world come to Colorado’s high country. For many of them, it’s the highest elevation they’ve ever visited, and often ever will. The dryness, the elevation, the air pressure, the intense sun exposure and the lack of oxygen demand a lot of compensation from the body. Sinclair’s experiences at altitude are consistent across every conversation I’ve had with physicians, athletes and other professionals when it comes to preparing your body to be active at altitude, from getting plenty of water to controlling the speed of your ascent to any elevation above 7000′ to consulting with a specialist regarding any pre-existing cardiac or respiratory conditions to how much oxygen one needs to mitigate symptoms of altitude sickness to decreasing elevation in case of an emergency. Any one of these experts will also tell you that the best ways to prepare your body for altitude is to get plenty of sleep, exercise regularly, and limit foods containing a lot of oil, grease and fat that will demand more from your body.

robert-ebert-santos

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Understanding the effects of nocturnal hypoxemia in healthy individuals at high altitude: A chance to further our understanding of the physiological effects on residents in Colorado’s mountain communities

The population of Summit County, Colorado is projected to grow by 56% between 2010 and 2030. Along with adjacent Park and Lake Counties there are now over 40,000 people living above 2800 meters elevation. This is the largest high altitude population in North America. As opposed to native populations in South America, Africa and Asia who have been residing above 2800 m for centuries, the North American residents are acclimatized but not adapted. Symptoms related to hypobaric hypoxemia are notable above 2500 m.  Recognized conditions associated with altitude include central sleep apnea leading to hypoxemia (abnormally low oxygen level in the blood) which activates the sympathetic nervous system. In susceptible persons this can cause systemic and pulmonary hypertension. The incidence of this potentially devastating side effect of mountain living is unknown.  In order to better understand the potential side effects of nocturnal oxygen desaturation in healthy individuals, it is beneficial to investigate the normal physiological changes that occur during sleep, which leads to low oxygen levels in all individuals.

When the body enters the sleep state, many of the behavioral mechanisms that are active during wakefulness are blunted, and it’s been found that different sleep stages have varying effects as well.  One of the major changes is a diminished response to hypercapnia (high carbon dioxide levels in the blood) and hypoxia.  During sleep, the CO2 set point is elevated from 40 mmHg to 45 mmHg, which results in reduced alveolar ventilation.   It’s also observed that minute ventilation is reduced, which is due to decreased tidal volumes that is normally compensated for with an increase in breathing frequency during wakefulness.  Also, during sleep, there tends to be upper airway narrowing that is normal and there is reduced reflex muscle activation of the pharyngeal dilator muscle.  All of the above factors contribute to decreased ventilation during sleep. 

A lot of what is understood about the effects of nocturnal hypoxemia is due to extensive studies in individuals with underlying diseases, and these studies are not always conducted at higher altitudes.  One such study investigated the effects of nocturnal desaturation (SaO2 < 90% occurring for > 30% of the sleep study) in chronic obstructive pulmonary disease (COPD) patients without a diagnosis of sleep apnea.  The authors found higher rates of dyspnea, increasing rates of worsening COPD symptoms, poorer quality of sleep and health-related quality of life.  Another such study found that some patients with COPD experience increased transient arterial hypoxemia (TAH) during rapid eye movement (REM) sleep.   In this study, the authors observed that the study subjects experienced increased pulmonary vascular resistance (which can lead to pulmonary hypertension) and a few subjects experienced an increase in their cardiac output. The authors found that individuals could experience a decrease in this phenomena by using nighttime oxygen therapy.

Studies, such as above, do not assist in identifying healthy individuals that may need early intervention due to nocturnal hypoxemia at altitude.  What about the healthy individuals without underlying diseases?  In the study conducted by Gries and Brooks in 1996, the authors collected data from 350 patients.  Their recorded average low saturation in the study of 350 subjects was a reported 90.4% lasting an average 2 seconds.  This study was conducted at the Rainbow Babies and Children’s Hospital located in Cleveland Ohio, at an elevation of 653 feet (198 m). This is one of the largest studies done to assess normal oxygen levels observed during sleep, and the results, along with results from other studies are displayed in Table 1.  As of right now, there is no equivolent study for subjects at elevations like that of Summit County, CO, which is at an average of 9110 feet (2777 m). Aside from the normal physiological changes noted above, the rates of developing underlying central sleep apnea leading to systemic and pulmonary hypertension is unknown.  Further, there are no guidelines as to initiating treatment in patients that may be experiencing adverse effects of high altitude nocturnal hypoxemia, because there is a lack of data to establish baseline normal values observed at this elevation.  This leads to unnecessary sleep studies, and further involvement of a myriad of healthcare professionals that have no specific guideline to reference when approached by one of these patients. 

In order to further our understanding of the effects of high altitude and nocturnal hypoxemia in healthy individuals, like that of Summit County, there has to be preliminary and ongoing research in these individuals.  Dr. Chris Ebert-Santos is currently conducting an overnight pulse oximetry study, which aims to recognize which symptoms they may or may not be experiencing, that are related to high altitude or sleep disorders, so that they may receive treatment, feel better, and remain active. 

At this moment, initial study results reveal a decreased average low night oxygen saturation from that of the study conducted by Gries and Brooks.  In a sample of just 14 individuals, the average low SpOs recorded overnight is at 81.3%, which is 9% lower than that recorded by Gries and Brooks (Graph 1).  The study is also revealing a trend in lower night oxygen saturations in individuals that have lived at elevation for a longer period of time (Graph 2). These findings suggest the need to expand and build on the current study being conducted by Dr. Chris and her team at Ebert Family Clinic. If interested, you may apply in-person at Ebert Family Clinic, where you will be required to fill out a health questionnaire on your length of residence at altitude, medical history, and possible symptoms related to high altitude.  Your basic vitals will be logged at the appointment.  After the first study, you will then be rescheduled in 12 months for a follow-up overnight study to monitor for any changes.  Overall, this study is designed to help with an understanding on the potential impact of high altitude on healthy individuals that are acclimated, but not necessarily adapted, to this environment.

Robert Clower is a second year physician assistant student at Red Rocks Community College in Arvada, CO.  His undergraduate degree was in Biology, which incorporated both medical health science courses as well as independent research courses in general biology and ecology.  While attending school at the University of North Georgia, Robert served in the Army National Guard for a cumulative time in service of 8 years.  After completing his undergraduate degree, Robert gained medical experience as an operating room assistant, which included assisting support staff with surgical preparation and patient transport throughout the hospital for surgical appointments.  Outside of his studies, Robert enjoys snowboarding, hiking, snowshoeing, exercising and spending time with family and friends. 

Sources

Summit County Population Projections: Summit County, CO – Official Website. Summit County Population Projections | Summit County, CO – Official Website. http://www.co.summit.co.us/519/Population-Projections. Accessed March 3, 2020.

Tintinalli JE, Ma OJ, Yealy DM, et al. Tintinallis Emergency Medicine: a Comprehensive Study Guide. New York: McGraw Hill Education; 2020.

Gupta P, Chhabra S. Prevalence, predictors and impact of nocturnal hypoxemia in non-apnoeic patients with COPD. 52 Monitoring Airway Disease. 2015.

Lemos VA, Antunes HKM, Santos RVT, Lira FS, Tufik S, Mello MT. High altitude exposure impairs sleep patterns, mood, and cognitive functions. Psychophysiology. 2012; 49 (9): 1298-1306.

Cingi C, Erkan AN, Rettinger G. Ear, nose, and throat effects of high altitude. European Archives of Oto-Rhino-Laryngology. 2009; 267 (3): 467-471.

High Altitude Hawai’i

Rising 13,803′ (4207 m) from the surface of the Pacific Ocean, Hawai’i’s tallest dormant volcano, Mauna Kea, reaches well into its own unique high altitude environment. Measured from its base on the ocean floor, it is the tallest mountain in the world, about 33,000′ (10,000 m) in height.

A frozen Haleakalā silversword. PC: Lyle Krannichfeld & Pueo Gallery

You may never have thought to find a high altitude environment on the tropical island chain, but Mauna Kea is just one of four peaks that summit over 8,000′. The next three are Mauna Loa (13,679′), Haleakalā (10,023′), and Hualālai (8,271′), with Haleakalā (“House of the Sun”) on the island of Maui and the other three on the Big Island. Each of these dormant volcanoes is home to species of plants and animals found only in Hawai’i, many of them only found around their respective peaks.

Sacred lands, whose access was once restricted to only the divine rulers of Hawaiian society, Mauna Kea now hosts 13 observatories and research staff in addition to its foreign and local visitors, many of whom make the historic pilgrimage to the summit from sea level in a matter of hours via an access road established in 1964.

Visitors to Mauna Kea are advised to acclimate at the Visitor Information Center which sits at 9,200′, although a particular length of time is not specified. In addition to the more intuitive precautions regarding pregnancy or heart and respiratory conditions, visitors in Hawaii are also warned against making an ascent within 24 hours of having been SCUBA diving, which may not be so obvious. You can find this and more helpful tips consistent with current high altitude research on their Public Safety brochure, which includes information about symptoms of HAPE (High Altitude Pulmonary Edema, featured in a previous article, and very common in the Colorado high country).

Poliahu visits Haleakalā. PC: Lyle Krannichfeld & Pueo Gallery

In addition to the hypoxic conditions, Mauna Kea and its aforementioned counterparts are also prone to the dryness and weather systems we see in Colorado, with snowfall above 10,000′ as recent as the past few days, a visit from Poliahu, Hawai’i’s own goddess of snow, and the subject of songs and hula dances in her honor.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not on a computer, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.