Acclimation, High Altitude, High Altitude Training & Fitness, Medicine, Mountaineering, Technology

Packing for a Spring Hut Trip

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Another winter has come and gone, and now Spring is in Colorado. Which means Winter will be back a couple more times before the snow all melts.

We’ve organized a team of friends from San Francisco, Denver, and Colorado high country for a backcountry excursion to one of Colorado’s 10th Mountain Division huts. The Benedict huts, our dwelling for two nights tucked into the wilderness outside of Aspen, are almost 6 miles from the trailhead, with an elevation gain of over 2000 ft. : a formidable trek, even for the experienced. And experience in wilderness trekking is one thing, but altitude is a game-changer. We will be well over 8000 ft. long before we reach the huts, so preparation for such an undertaking requires as much attention to mental, physical and physiological condition as much as clothing, gear and rations.

Weather & Conditions

This has everything to do with the weather, so it’s important to be on top of tracking all the resources available to you. At the top of my list in this region is the Colorado Avalanche Information Center. They provide up-to-date reports for high-risk areas around the state according to a comprehensive and easy-to-understand rating system. When considering this information, I always remember that our trek will take us through several types of terrain, and thus, several types of conditions: in and out of trees, varying steepness and exposure (to sun, wind, precipitation, etc.), all kinds of microclimates and environments (wetlands, scree fields).

The Colorado Avalanche Information Center provides no shortage of visuals to aid your risk assessment.

As far as incoming weather patterns are concerned, one of the most popular and reliable forecasts endorsed by people who play outside in Colorado is Open Snow. Founding meteorologist Joel Gratz updates local forecasts regularly, and provides information on what to expect with the outdoor adventurers in mind.

For our upcoming hut trip, it looks like the storm we’re expecting will be warmer and milder than recent systems, with most of it heading toward the northern mountain region. That being said, however, I’m keeping in mind that any projected weather system can be just a few degrees colder, a few inches wetter, and a few miles closer and change conditions dramatically. So let’s talk about how we can anticipate this with …

Gear & Clothing

The Commute

In any season in Colorado, there are essential comforts I always pack to get me to and from any hut that requires a hike, and to keep me happy while I’m enjoying the site. Dead of Winter, Height of Summer alike, the sun and glare is liable to be more intense than anything you’ve ever experienced at sea-level, while at the same time, the temperature and lack of humidity can cool your body significantly, night or day. Depending on how strenuous the commute is or how active you intend to be even after arriving at your destination, you may be constantly shedding, then adding, then shedding, then adding layers, so keep it all very accessible.

For this particular trek, I’ll be in snow gear. Basically anything I’d wear snowboarding: snow pants, outer shell on top, hat, gloves. I want it to be warm and waterproof on the outside. Underneath this shell, I want layers that I can strip down to as soon as I start moving and sweating with a 40 -60 lb. pack on. Unless the storm turns out to be much more intense (in which case, I’ll keep the outer layers on), I expect my skin to be steaming, so I won’t want to be in much more than warm compression tights, a t-shirt, and a light pullover. Your outer shell is for blizzards and water-proofing, so whatever you are stripping down to should be significantly lighter. Also, sunglasses or goggles. The glare from snow is significant. I bring both, because goggles get way too hot while I’m trekking uphill.

Here’s the tricky part: What are you going to wear on your feet? This is where the weather forecast comes in. This time of year, after such a snowy winter, I’m expecting most of the trail to be covered in snow, and the storm moving in is likely to bring more. I will be scoping out the trail pre-storm, which will give me a much better idea of what to expect, but I’m preparing to have snowshoes or a split-board and skins strapped to my snowboard boots. Of course, skis with skins are another alternative. There is a very slim chance most of the snow on the trail will be melted down, in which case I would probably opt for waterproof boots instead, which I would expect to get pretty muddy.

Avalanche Gear

Whether it’s on the commute or while you explore terrain around the hut during your stay, there are some essentials you can pack for the worst-case scenario. I’ve gone into more detail in a previous blog, but standards that I will be keeping on me are a shovel, probe and beacon. But these tools are only a small part of avalanche preparedness. More important than the endless supply of technology you can invest in is knowing what conditions and natural phenomena to be aware of during your trek, and the Colorado Avalanche Information Center is a great place to start familiarizing yourself with these.

Cabin Comforts

There is only one limiting factor to this list, but it is considerable: how much you can carry. For six miles. Uphill. In snow.

Most of the huts in the 10th Mountain Division hut system are equipped with soft mattresses, small pillows, and blankets. The kitchens are stocked with utensils and dishes, there is toilet paper, paper towels, hand sanitizer and dish soap, as well as ample supplies of wood for burning in the wood stoves. So most of your weight will be food and drinks.

I always pack a sleeping bag and extra pillow, because the guaranteed warmth and comfort are worth it when you’ve spent your day being intensely active outdoors. And keep in mind you’ll want warm, dry layers to change into that you haven’t been hiking and sweating in all day. What do you want to be wearing when you’re lounging around the cabin reading, cooking, eating, playing cards, etc.? For me, this looks like socks, long underwear, a pullover and slippers that I can crush into my pack. And then what are you going to throw on when you have to go back outside into the dark cold of night to use the outhouse? Your Colorado uniform: a hoodie.

There won’t be running water, so you can’t expect to shower. When you’re in the wilderness for a long time and need to be discerning about how much weight you carry that isn’t food and water, bathing is of low priority. But for a short trip like this, I don’t mind bringing some form of wet wipes; they’re light-weight and take up very little space. Toothbrush and toothpaste should be obvious, though.

Medication & Acclimation

From climbing Mt. Fuji to Colorado’s 14er’s, I’ve noticed a lot of people bringing pressurized cans of oxygen. High altitude research has taught me just how temporary and unnecessary this trend is. Often, the most effective remedy for altitude sickness is 5 – 10 minutes on oxygen. I’m pretty sure you’ll blow through a whole can of gas-station aerosol oxygen before it does you any lasting good.

Avoid this by giving yourself time to acclimate before you get to extreme elevation. Ebert Family Clinic in Frisco, Colorado, specialists in high altitude research, always recommend keeping track of blood oxygen saturation with a pulse oximeter, and this is something small, inexpensive and very portable. Our team will be spending at least 24 hours at altitude before we embark on the trek to the hut. This way, members from lower elevations will have access to an oxygen concentrator to facilitate acclimation.

Physician and high altitude expert Dr. Christine Ebert-Santos recommends packing the following mediations for hut trips: Acetazolamide, Benadryl, Ibuprofen, an EpiPen, Acetaminophen, and topical antibiotic oinment. Of course, be aware of any allergies to medication in your party. It is also helpful to be aware of what symptoms you may expect to experience, should you start having trouble acclimating, including dizziness, nausea, hyperventilation, and fatigue.

Food & Water

This is where most of the weight you pack in will be. Again, no running water at the hut, so expect to boil all the water you need for drinking if you run out of what you bring. There are lots of compact water purification systems you can easily pack as well. For our six mile trek to the cabin, I will have a Camel Bak and a couple Nalgene-sized thermoses full of water tucked into my pack.

You don’t want to have to cook everything you bring, so snacks you can easily access and eat are essential, especially for the trail. For this particular hike, I expect to burn more calories more quickly than any other average day, so I want lots of nutrients per gram: pistachios, energy bars, jerky … And don’t underestimate the power of sugar and caffeine, this is precisely the kind of work your body acts quickly to convert these nutrients to energy for. And yes, I mean chocolate. (Fruit also contain a lot of valuable sugar, I’m told.)

While we’re at the cabin, we’ll have access to a propane stove, so we’ll be able to cook some hearty meals. Bacon, fruit, yogurt, bagels and cream cheese are all easy breakfast foods to pack. If you are fortunate enough to be on a hut trip with Dr. Chris herself, you will have pancakes at least once. It’s also easy enough to bring fixings for the most epic sandwich you’ve ever had: guacamole, sprouts, turkey, ham, greens, tomatoes, bread; and remember, it’s a good chance to justify all the calories you get from mayonnaise and mustard.

And speaking of calories and sugar, I feel like whiskey and beer were invented to accompany the warmth of a fire in a remote, mountain cabin. The good news is that you are sure to be carrying less out than you did in. The bad news is that hangovers are exacerbated by high altitude, so pay more attention to your consumption than you would at any lower elevation, and be sure to have plenty of drinkable water at hand.

Am I Ready?

Hut trips in Colorado are mentally and physically challenging, even in the best conditions. The more time you give yourself, the better. Know before you go and don’t go alone. And don’t be intimidated. I’ve successfully guided friends from sea-level who don’t consider themselves athletic to destinations well above the tree line without incident.

Always be checking in with your body, your team, and your environment.

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.

Acclimation, Health, High Altitude, Medicine, Parkinsons

Increasing the Altitude to Decrease the Symptoms of Parkinson’s Disease

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By Jessica Thomas PA-S

 In May of 2009 Michael J Fox’s “Adventures of an Incurable Optimist” aired on ABC. This special chronicled his decision to battle the effects of his Parkinson’s disease with optimism and hope. During the production of this special he journeyed to the Kingdom of Bhutan. While in Bhutan, Michael J. Fox noted that his symptoms of Parkinson’s disease had almost completely vanished. 

 Bhutan lies between China and India, on top of the Himalayan Mountains. Bhutan is an extremely unique country since it is cut off from the rest of the world and has a desire to keep its culture unaffected by today’s modernization and globalization. Altitudes in Bhutan average 8-9,000 ft above sea level. When Fox’s parkinsonian symptoms decreased, he couldn’t help but wonder about the connection between the increased altitudes and the decrease of his symptoms. 

With more research into the topic it becomes apparent that Michael J. Fox was not the first person with Parkinson’s disease to notice a difference when in the high altitudes. According to Fred Ransdell, author of Shaky Man Walking, he has had two individual experiences where his tremors almost completely vanished. The first takes place whenever he is flying. Mr. Ransdell states that as the plane gains altitude he will remain completely asymptomatic until the plane lands. The second was when he was driving over a mountain pass at 9,000 feet elevation and he states that at that moment he noticed that his tremors were gone. How can this be? 

The first theory for why the increased altitude (>6,000 ft above sea level) decreases symptoms of Parkinson’s disease stems from the pH of our blood. When at higher altitudes we breathe faster and deeper in order to get enough oxygen into our lungs. When we breathe, our body discards carbon dioxide in proportion to oxygen we take in. Knowing this, it is understood that the increase in breathing also causes our body to get rid of more carbon dioxide from our blood which in turn will raise the blood pH making it more alkaline in nature. Naturally our blood is alkaline (approximately a pH of 7.3-7.4), otherwise death would ensue. Acids in our body are generally cell by-products, meaning that when our body is making energy or other necessities to life, they will give off acids. These acids are processed through the lymphatic system. When we have increased acids in our body the lymphatic system can get backed up. The back-up of acids in the body can cause stiffness, pain, and swelling. As the back-up worsens, deeper problems occur that affect the function of the cells and the tissues which can turn off hormone, steroid, and neurotransmitter production. Although this is an oversimplification of the process, it is easy to see that the more acidic the blood is, the more we may see increased symptoms of Parkinson’s disease. Correction of this acidosis is thought to preserve muscle mass in conditions like Parkinson’s and help with coordination. 

The second theory revolves around hypoxia and the main neurotransmitter that Parkinson’s disease effects. A study published in Springer titled Intermittent Hypoxia and Experimental Parkinson’s Disease found a link between hypoxia and the increase of dopamine synthesis. We know that atmospheric pressure reduces with altitude and with that so does the amount of oxygen. The reduction in the partial pressure of inspired oxygen at higher altitudes lowers the oxygen saturation of the blood which leads to hypoxia. But what does this have to do with parkinsonian symptoms? The results of this study revealed that a two-week course of intermittent hypoxia training in patients with Parkinson’s disease increased dopamine synthesis in old and experimental PD animals which restored the asymmetry of DA distribution in the brain. Parkinson’s disease is a progressive disorder that affects dopamine-producing neurons in the brain. When these neurons are destroyed, the production of dopamine severely decreases and we see symptoms such as tremors, slowness, stiffness, and balance problems

The Michael J. Fox Foundation for Parkinson’s Research received a research grant in 2018 to study the effects of altitude on Parkinson’s Disease. The study consists of two individual parts. The first part is a focused survey that asks individuals with Parkinson’s about their best and worst experiences with their symptoms during their travels in the last 2 years. The second part of the study will be an in-depth survey that with capture the travel experiences prospectively. 

Maybe we see the decrease in symptoms because of the hypoxia or maybe it is due to the increased pH of our blood, or maybe it is because of something we have yet to discover. With the new study from the Michael J. Fox Foundation on the horizon, answers to this question may be within our grasps. 

Jessica Thomas is a Physician Assistant student at Des Moines University in Iowa. Following graduation Jessica will be practicing family medicine in small town Iowa with an emphasis on preventative care and pediatrics. Over  the course of the last year she has had the joy of living and working in 6 different states around the country and has experienced many different climates and learned how to care for the ailments that occur in the different regions of the United States. When not at work or studying, you can find her reading on her porch swing, watching Hallmark movies in bed on Sunday afternoons, or spending time with her family and friends. 

References

F. R. (n.d.). Altitude and Parkinson’s disease. Retrieved from https://www.shakymanwalking.com/altitude-and-parkinson-s.html

Altitude in Bhutan. (n.d.). Retrieved April 12, 2019, from https://www.bhutantravelbureau.com/about-bhutan/township-altitudes/

Belikova, M. V., Kolesnikova, E. E., & Serebrovskaya, T. V. (1970, January 01). Intermittent Hypoxia and Experimental Parkinson’s Disease. Retrieved from https://link.springer.com/chapter/10.1007/978-1-4471-2906-6_12

Bloem, B. R., & Faber, M. J. (n.d.). Exploring the Effect of Altitude on Parkinson’s Disease. Retrieved April 12, 2019, from https://staging.michaeljfox.org/foundation/grant-detail.php?grant_id=1813

Ma, H., Wang, Y., Wu, J., Luo, P., & Han, B. (2015, September 01). Long-Term Exposure to High Altitude Affects Response Inhibition in the Conflict-monitoring Stage. Retrieved April 12, 2019, from https://www.nature.com/articles/srep13701

Parkinson’s and Nutrition. (n.d.). Retrieved from http://parkinsonplace.org/programs-services/parkinsons-and-nutrition/

Schwalfenberg, G. K. (2012). The alkaline diet: Is there evidence that an alkaline pH diet benefits health? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3195546/)

Child Growth & Development

Expected Variations in Nocturnal Oxygen Saturation in Infants: Comparing Needs at Sea Level to High Altitude

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What is a normal overnight oxygen saturation for a child? This question is asked frequently by parents who have a child that may be requiring oxygen after evaluation. As healthcare providers working at various altitudes and caring for children, knowing the change in baseline oxygen saturations when at different altitudes is key to educating patients.  There are physiologic changes that result in transient changes in respiratory rate and volume while sleeping which will be discussed before exploring nocturnal oxygen needs at sea level versus needs at high altitude in healthy children. 

To begin, I will define a few terms that may not be familiar, but may be used when discussing oxygen needs. Oxygen saturation is defined as the amount of oxygen bound to hemoglobin in the blood, expressed as a percentage of maximal binding capacity.1 The simplest and most non-invasive way to obtain this information is through a pulse oximeter, which is placed on the patient’s finger, toe, or ear when vital signs are being taken. Oxygen saturation is known as the “5th vital sign” and tells medical providers whether or not a patient is delivering enough oxygen to their body. Hypoxemia is defined as insufficient oxygenation of the blood.2 There are multiple causes of hypoxemia, however we categorize hypoxemia as an oxygen saturation of less than 90 percent on a pulse oximeter. Finally, we use the term desaturation to describe a patient whose oxygen saturation continues to go below expected values.

In healthy, full-term infants, sleeping approximately 16 to 18 out of 24 hours is expected. A majority of their sleep cycle is REM and occurs when they fall asleep, with shorter duration of NREM sleep. As the child’s nervous system matures, there will be predictable changes in their sleep cycle, which will be more similar to a child or an adolescent. In children and adolescents, NREM is entered when they initially fall asleep, and accounts for approximately 75 percent of total sleep time, with alterations every 90 to 100 minutes of REM and NREM. In addition, there is a progressive increase in REM in the final third of the night.3 Understanding these cycles, what occurs during these cycles, and how they change over time are important in understanding the physiological changes (Table 1) that occur while you are sleeping.

  The physiological changes that we are focused on are decreased respiratory rate and decreased respiratory volume, which are seen in NREM and in the phasic stage of REM. In infants, periodic breathing is also an observed pattern of breathing that is expected after the first 48 hours of life until about 6 months of age. Periodic breathing is recurrent central apnea interrupted by breathing efforts. This topic will further be discussed in the high-altitude study, as these episodes are more common at high altitude.4

Table 1: Normal physiologic changes during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep.5

In a study conducted at sea level in Brisbane, Queensland, Australia, 34 healthy term infants were studied at 2 weeks, 3, 6, 12, and 24 months in a prospective longitudinal cohort study. The study mentioned that there was limited data on reference ranges for normal nocturnal oxygen in infants, but that they aimed to develop a cumulative frequency (CF) reference-curve. This curve may be used as a tool to compare a child’s nocturnal oxygen saturation to see if the infant falls within the range for infants that are similar in age (Figure 1). Overall, the median nocturnal saturation was between 98 and 99 percent, for infants living at sea level.6 

In an additional study, conducted at high altitude in Bogotá, Colombia, 122 healthy full-term infants were studied in 4 various groups. These groups were coupled differently and were only monitored until 18 months of age. The groups were <45 days, 3 to 4 months, 6 to 7 months, and 10 to 18 months. In addition to these groups, 50 infants completed three overnight PSG studies and were analyzed as a longitudinal sub-cohort.

In this study, their overall data was presented differently and they also looked at SpO2 during wakefulness and respiratory events, which are more likely to occur at higher altitudes. An interesting finding, that was not present in the study at sea level in patients of similar size, age, and weight, was the increase in total, central, and obstructive apneas. In addition, there were also very high frequency oxygen desaturation events that again are not seen when living at lower altitudes. These events were reported as normal in infants living at high altitude. Overall, the median SpO2 was between 92 and 94 percent at high altitude.7 

To conclude, the median oxygen saturations at sea level were between 98 and 99 percent and between 92 and 94 percent at high-altitude. This said periodic breathing, which is normal until six months of age at any altitude, causes transient desaturations and are more common at high altitude. Apneic events are more commonly seen in infants at altitude, but are considered normal.  These studies have offered reference ranges and tools to better aid clinical judgement when caring for a patient that may require oxygen.

–Felicia S.

References:

1. Oxygen saturation. Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved March 23, 2019, from https://medical-dictionary.thefreedictionary.com/oxygen+saturation.

2. Hypoxemia. The American Heritage® Medical Dictionary. (2007). Retrieved March 23, 2019, from https://medical-dictionary.thefreedictionary.com/hypoxemia.

3. Wise, M., and Glaze, D. (2018). Sleep physiology in children. UpToDate. Retrieved March 23, 2019, from https://www-uptodate-com.ezproxy.stfrancis.edu/contents/sleep-physiology-in-children?search=sleep%20physiology%20in%20children&source=search_result&selectedTitle=1~134&usage_type=default&display_rank=1#H4. 

4. MacLean, J.E., Fitzgerald, D., & Waters, K. (2015). Developmental changes in sleep and breathing across infancy and childhood. Pediatric Respiratory Reviews, 16(4), 276-284.

5. Hanyang Medical Reviews. 2013 Nov;33(4):190-196. https://doi.org/10.7599/hmr.2013.33.4.190.

6. Terrill, P., Dakin, C., Hughes, I., Yuill, M., & Parsley, C. (2015). Nocturnal oxygen saturation profiles of healthy term infants. Archives of Disease in Childhood, 100(1), 18-23. 

7. Duenas-Meza, E., Bazurto-Zapata, M., Gozal, D., Gonzalez-Garcia, M., Duran-Cantolla, J., Torres-Duque, C. (2015) Overnight Polysomnographic Characteristics and Oxygen Saturation of Healthy Infants, 1 to 18 Months of Age, Born and Residing at High Altitude (2,640 Meters). Chest, 148(1), 120-127.

Acclimation

Sleep at Altitude

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Reported Sleep Disturbances

Many travelers report a decrease of quality of sleep when traveling from sea-level to high altitudes. Newcomers to altitude typically describe trouble falling asleep and frequent wakings throughout the night.7 One study determined that 46% of 100 Iranian ski tourists reported frequent awakenings and other sleep disturbances such as insomnia during their first night sleeping at 3,500 m.5,7 Another study analyzed data from reports of 305 Chinese soldiers transported from 500 m to 3,700 m in Lhasa and found similar results. Approximately, 32% of the soldiers reported insomnia in the first night at altitude and 74% of 246 workers who were air-lifted to the South Pole at 2,835 m reported difficulty falling and staying asleep throughout the first week.1

Change in Breathing Pattern

Many theories state that the “periodic breathing pattern,” common during sleep at high altitude, is a potential cause of sleep disturbances. Periodic breathing is a form of Cheyne-Stokes respiration and reflects changes in neural signaling due to hypoxia and alkalosis during sleep.4 Hypoxia is a respiratory stimulant while alkalosis is a respiratory depressant.4 This mixed signaling is the source of the altered breathing during non-REM sleep encountered at altitudes over 2500 m. The frequency of periodic breathing during sleep increases as the altitude increases.3,4,7

Decreased Sleep Efficiency 

Compared with sea level, several studies have depicted that sleep at higher altitude is characterized by decreased sleep efficiency, prolonged superficial stages of sleep, and reduced stages of deep sleep.12 The image below is a qualitative representation of sleep structure recorded at sea level and at high altitude. The area encircled by the outer line reflects the time in bed and the area of the shaded inner pie chart the time asleep.7,13 The fractions of superficial stages of sleep are symbolized by “NR1&2,” the fractions of deep non-rapid eye movement sleep are represented by “NR3&4,” and the stages of  rapid eye movement sleep are exemplified by “REM.”

Fig. 1. Depicts a qualitative comparison of sleep quality at sea level vs. altitude > 1,500 m13

Shift in Brain Waves 

Everyone is aware of the importance of quality of sleep when it comes to memory processing. One study has associated a decline in sleep-related memory consolidation with the decrease in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects observed overnight at high altitude.15  Another study by Stadelmann et al. discovered that quantitative spectral analysis of frontal and central EEG derivations reflected an altitude-dependent decrease in slow wave activity.14

Daytime Performance

A study, analyzing sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m, discusses the association between sleep disturbances with poor performance in driving simulator tests.11 Studies performed at altitudes of 3800-3900 have revealed that supplementing with nocturnal oxygen improves daytime performance in neuropsychological tests, increases overall sleep quality, and reduces the occurrence of periodic breathing. 9,10 Although further studies are needed, the stated findings suggest that altitude-related alterations in sleep may negatively affect overall daytime performance.7

Can We Acclimate to High Altitude? 

Over time, research points to some sort of acclimation concerning sleep at high altitude; although research analyzing acclimation is very limited. Studies analyzing altitudes between 4,5559 m to 6,835 m have determined that the frequency of periodic breathing increased with the time spent at high altitude altitude.2,12 Opposingly, in studies at lower altitudes such as 1,650 m, 2,590 m and 3,450 m, periodic breathing decreased from the first to the second night.6,8 These observations suggest that there is an altitude-dependent effect of acclimatization on sleep structure. Interestingly, the same study that determined an increase in periodic breathing with time spent at an altitude of 4,559 also noted a decrease in arousal index and normalization of nocturnal oxygen saturation with increased time spent at high altitude.12 Stadelmann et al. determined that there was a statistically significant increase in the number of sleep cycles at higher altitudes with the longer the stay at altitude.14

Dr. Ebert-Santos’s Decision to Continue the Research

Despite recent advances in our understanding of sleep at high altitude, further research is needed to understand how demographics may alter sleep at high altitude, to determine the process of sleep-acclimatization, and to uncover the characteristics of sleep in local-highlanders.7 Dr. Ebert- Santos continues to be an advocate for the Summit County community regarding the effects of high altitude on health and has decided to pursue a study researching the effects of altitude on oxygen saturation during sleep of adults ranging from the ages 25-65 years old. Stay tuned for her process, her results, and her conclusions! 

Caroline, PA-S

References:

  1. Anderson PJ, Wiste HJ, Ostby SA, Miller AD, Ceridon ML, Johnson BD. Sleep disordered breathing and acute mountain sickness in workers rapidly transported to the South Pole (2835m). Respir Physiol Neurobiol 210: 38–43, 2015.
  2. Bloch KE, Latshang TD, Turk AJ, Hess T, Hefti U, Merz TM, Bosch MM, Barthelmes D, Hefti JP, Maggiorini M, Schoch OD. Nocturnal periodic breathing during acclimatization at very high altitude at Mount Muztagh Ata (7,546 m). Am J Respir Crit Care Med 182: 562–568, 2010.
  3. Erba P, Anastasi S, Senn O, Maggiorini M, Bloch KE. Acute mountain sickness is related to nocturnal hypoxemia but not to hypoventilation. Eur Respir J 24: 303–308, 2004.
  4. Gallagher, Scot A. High altitude illness: Physiology, risk factors, and general prevention.  Up-to-date.Waltham, Mass.: UpToDate; September 20, 2017. www.uptodate.com. Accessed March 20, 2019.
  5. Jafarian S, Gorouhi F, Taghva A, Lotfi J. High-altitude sleep disturbance: results of the Groningen Sleep Quality Questionnaire survey. Sleep Med 9: 446–449, 2008.
  6. Kohler M, Kriemler S, Wilhelm EM, Brunner-Larocca H, Zehnder M, Bloch KE. Children at high altitude have less nocturnal periodic breathing than adults. Eur Respir J 32: 189–197, 2008.
  7. Konrad E. Bloch, Jana C. Buenzil, Tsogyal D. Latshang, and Silvia Ulrich. Sleep at high altitude: guesses and facts. Journal of Applied Physiology 2015 119:12, 1466-1480. 
  8. Latshang TD, Lo Cascio CM, Stowhas AC, Grimm M, Stadelmann K, Tesler N, Achermann P, Huber R, Kohler M, Bloch KE. Are nocturnal breathing, sleep, and cognitive performance impaired at moderate altitude (1,630–2,590 m)? Sleep 36: 1969–1976, 2013.
  9. Li P, Zhang G, You HY, Zheng R, Gao YQ. Training-dependent cognitive advantage is suppressed at high altitude. Physiol Behav 106: 439–445, 2012.
  10. Luks AM, van MH, Batarse RR, Powell FL, Grant I, West JB. Room oxygen enrichment improves sleep and subsequent day-time performance at high altitude. Respir Physiol 113: 247–258, 1998.
  11. Nussbaumer-Ochsner Y, Schuepfer N, Ulrich S, Bloch KE. Exacerbation of sleep apnoea by frequent central events in patients with the obstructive sleep apnoea syndrome at altitude: a randomised trial. Thorax 65: 429–435, 2010.
  12. Nussbaumer-Ochsner Y, Ursprung J, Siebenmann C, Maggiorini M, Bloch KE. Effect of short-term acclimatization to high altitude on sleep and nocturnal breathing. Sleep 35: 419–423, 2012.
  13. Rechtschaffen A, Kales A. A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects. Washington, DC: Public Health Service, US Government Printing Office, 1968.
  14. Stadelmann K, Latshang TD, Lo Cascio CM, Tesler N, Stoewhas AC, Kohler M, Bloch KE, Huber R, Achermann P. Quantitative changes in the sleep EEG at moderate altitude (1630 m and 2590 m). PLoS One 8: e76945, 2013.
  15. Tesler N, Latshang TD, Lo Cascio CM, Stadelmann K, Stoewhas AC, Kohler M, Bloch KE, Achermann P, Huber R. Ascent to moderate altitude impairs overnight memory improvements. Physiol Behav 139: 121–126, 2015.
Mountaineering

Beyond Acclimatization: Avalanche Safety

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Spring of 2019 in the Colorado high country has certainly been one to remember. Unsure of where work would take me, I waited until the last week to commit to a ski pass for the season, and after all the storms we’ve seen, I’m glad I did. And I can tell that many others are just as excited. I’ve never seen so many people on the weekend slopes and on the surrounding highways.

Meanwhile, the central mountain region has seen a record number of avalanches and fatalities, and Colorado retains the highest statistics in the country. People from all over the world come for world-class skiing, but many experienced locals have been avalanche victims. We often assume they are skiers and snowboarders, but avalanche fatalities happen just as often to snowmobilers and backcountry hikers. Another misconception is that these avalanches are happening exclusively in the backcountry, which they are not. Three young men this year barely escaped an inbounds avalanche at Breckenridge ski area, while two weren’t so fortunate in New Mexico’s Taos Ski Valley.

But the wild Colorado backcountry still beckons and many continue to answer. Having spent over ten years in Summit County, home to Colorado’s greatest number of peaks over 14,000 ft., my family and I are regulars in the backcountry, in all seasons. Experiencing these mountains in all kinds of conditions can make you much more aware of the risks inherent in the outdoor recreation scene here, but it clearly does not guarantee your safety.

This coming April, I’ll be on a trek to one of the 10th Mountain Division huts, a series of remote cabins, most of which are only accessible by foot, snowshoe or ski. In the summer, the trails tend to be well-maintained and obvious, but I’ve seen first-hand that conditions in snow, even during a mild season, can make the commute much more difficult and much more dangerous. Carrying all your supplies on your back certainly increases your vulnerability and decreases your ability to respond quickly to unexpected events, as you are more liable to sink deeper into loose snow-pack.

Shrine Mountain Inn, one of the more easily-accessed huts in the 10th Mountain Division system, even offers running water and electricity, as is within most cellular networks.

As you may have been taught, luck favors the prepared. If there’s one way to tell a local from a visitor in the high country here, it’s how prepared they are to be outdoors in variable conditions, and as the sole resident on the upcoming hut trip, I will be passing on all the proper safety precautions to my less-experienced San Francisco counterparts.

Expeditions to more popular huts at lower elevations during mild winters tend to be more about preparing comforts: boots, snowshoes, skis that fit well; warm, dry layers; plenty of water; etc. What makes me especially wary of the increased danger and the necessity of avalanche equipment is the alternating warm weather and snow storms. This means several alternating layers of heavy snow and light pack, making large slabs of snow (and ice) more prone to letting loose and leveling everything in their way.

While there are some obvious measures you can take and gear you can pack to boost your ability to respond in case of an avalanche, professionals across the state can’t recommend official avalanche safety certification highly enough. It’s available across the globe, thanks to the American Institute for Avalanche Research and Education (AIARE), and Colorado is one of the best places to get certified.

Technology has come a long way when it comes to avalanche safety, but the three things AIARE recommends you carry while in the backcountry are a transceiver (a beacon), a probe (for finding buried victims) and a shovel. Local conditions are updated daily on Colorado’s Information Marketplace Avalanche Information Center. Be sure to check the very day you plan to be in areas of high risk, and as frequently as possible.

On a closing note, keep in mind that avalanche safety measures aren’t always as intuitive as carrying a shovel. One major statistic we should all keep in mind is that most avalanches don’t happen on their own, and are caused by the victims themselves, often because there is more than one person traversing a slope at a time. In this case, safety is not in numbers: one person on a slope at a time.

I love Colorado, I love the mountains, I love the ski slopes, I always appreciate the vast open wilderness of the Rockies, and I’m looking forward to many more upcoming excursions in them. Hopefully this has armed you with some knowledge to better equip your daring high country adventures. It is just the tip of the proverbial ice berg, however, and on top of certification and gear, there is no end to the value that actual experience adds.

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.

Mountaineering

A Sea-Level Dweller Climbs Cotopaxi

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During the winter of 2018, the Little Rock Climbing Center Alpine team ventured south to Ecuador for a mountaineering expedition. However, poor weather and high avalanche risk thwarted our summit attempts of Cayambe (18,996’, 5789 m) and Cotopaxi (19,347’, 5896 m). This winter (2019), we returned to Ecuador to attempt to summit Cotopaxi again, with a new and improved acclimatization plan and high hopes for better weather. Little Rock, AR sits at a mere 335 ft (102 m) above sea level … but we are lucky to have Pinnacle Mountain, with 750’ (228 m) of elevation gain to train on. A small mountain is better than no mountain!  My training plan entailed hiking Pinnacle Mtn 2-3 times during the week, and then hiking or mountain biking on the weekend for approximately 3 months. I also rock climbed at the climbing gym 2 days a week, but Cotopaxi is not a technical climb, so that was mostly for fun.  I took a week-long trip out to Colorado in September to reassess how my body reacts to high altitude.  During this week we rock climbed in Boulder Canyon, Idaho Falls, and climbed the first and second Flat Irons, as well as hiked up to Sky Pond at Rocky Mountain National Park, hiked Mt. Bierstadt, and hiked out to Crystal Mill with Dr. Chris. I chose not to run too much this year for training because I have a meniscal tear in my left knee that gets aggravated on long runs. 

We arrived in Quito, the capitol of Ecuador on December 30. Quito sits at 9,350’ (2849 m), so we took our first day pretty easy, and walked from our hotel to the older part of town with historic churches and cathedrals. Walking up the many flights of stairs in the Basilica del Voto Nacional got my heart pumping and legs and lungs burning! New Year’s Eve in the La Mariscal area of Quito was quite entertaining and a little rowdy, with fireworks, burning of effigies, and jumping over the fires. Our first day hike was up Rucu Pichincha (15,413’, 4697 m), a stratovolcano right in Quito! The TeleferiQo (a gondola) brings you up to 12,943’ (3945 m) where you begin the hike. The hike up Rucu Pichincha starts out mellow, on smooth trail with short steep, punchy climbs. Once you near the top, the steepness increases and the last few hundred feet involve very easy scrambling on sharp volcanic rock. The winter in Ecuador is typically the rainy season, so scattered showers and electrical storms are very common. However, we lucked out with perfect weather on Rucu Pichincha, and fantastic views of the big mountains – Cotopaxi, Antisana, and Chimborazo. The next day we drove to the base of the Ilinizas, and just missed the horse that was supposed to carry our packs up to the refugio. It was about a 3,000’ (914 m) climb up to Refugio Nuevos Horizontes, in relentless wind and dense fog. About half way up to the refugio, a lone figure emerged out of the fog. The horse that was supposed to carry out gear was carefully making his way down the mountain, such a surreal sight! We spent the night sharing bunk beds, packed like sardines in the tiny refugio (15, 696’, 4784 m). The next morning, the wind hadn’t let up, and the fog was still suffocatingly thick. A few groups had attempted an early morning ascent of Iliniza Norte, but said it was too icy and windy to summit. Our mountain guide, Alejo, suggested we traverse around the backside of Iliniza Norte to avoid the worst of the wind, and his advice was on point. The wind was whipping so hard at the summit (16,818’, 5126 m), we spent less than 5 minutes on top before beginning our decent back to the car. The wind was so strong on our descent (upwards of 60mph!), it knocked me off my feet several times. Next time I will use my hiking poles when it is so windy! We spent the next day resting and recuperating at Los Mortinos Hacienda, a cozy B&B at the edge of Cotopaxi National Park where we watched llamas graze, went horseback riding, and dined on fresh trout from a nearby river. 

The next day we drove up to the Cotopaxi parking lot, and slogged up the soft, ashy trail for an hour or so before reaching Refugio Jose Rivas (15,744’, 4798 m) at the base of Cotopaxi. At the refugio we ate some dinner, hydrated, and then tried to rest as much as possible. Alejo woke us up at 10pm and by 11pm we were on our way up the volcano. The skies were finally clear and calm after days of clouds and windy weather, all of the stars were out and we watched an impressive lightning storm down in Quito. We began the trek in mountaineering boots as the glacier starts about two hours uphill. While I felt fine the day before hiking up to the refugio, I had a pretty decent headache when we woke up. My right foot kept falling asleep in my mountaineering boot, and I was starting to overheat because I had too many layers on. This was the first time on the trip that I felt bad, and doubts about a successful summit started to creep in my mind. Alejo asked if I wanted to turn around, but even though I didn’t feel good, I didn’t feel bad enough to turn around. After about two hours of hiking, we reached the glacier and donned our crampons. And then I started to finally feel GOOD! As long as I kept switching my stepping technique, alternating between duck-footing, side-stepping, and French technique, my right foot wouldn’t fall asleep. The higher we climbed, the better I felt! About an hour away from the summit is when it really began to get steep. Alejo said it would be really steep, then a little easier, and then really steep again. We trudged on. And it got steep — really, REALLY steep. Just keep moving. Step up, rest, step up again, rest. Repeat. The mountain seemed to keep going up and up and up. But then around 8am we were at the top of Cotopaxi! I had seen photos of the summit, but seeing smoke coming out of the crater with my own eyes was mind-blowing. We ACTUALLY made it! We waited for Ian and his guide to summit, and then spent the better part of an hour taking photos and enjoying what Alejo said was the nicest weather he’d ever experienced at the summit. 

Ian brought along an Accumed Pulse Oximeter, so being the science nerd that I am, I measured my oxygen saturation percentage at various elevations over the course of the trip. While the percentage of oxygen in the air is the same, the fall in atmospheric pressure at high altitude decreases the driving pressure for gas exchange in the lungs, leading to lower oxygen saturation levels.  I measured my oxygen saturation level on my right index finger after being seated for approximately 5 minutes. The Accumed Pulse Oximeter is a small battery-powered device that measures the ratio of red light and infra-red light that is absorbed through the finger to calculate oxygen saturation levels.

Here is a table of my oxygen saturation levels at various elevations throughout the trip:

Day Location Elevation  (ft/m) O2 saturation (%)
1 Quito 9,350/2849 80
2 Summit of Rucu Pichincha 15,413/4697 75
3 Refugio Nuevos Horizontes 15, 696/4784 74
7 Summit of Cotopaxi 19,347/5896 57

Before reading too much into this very limited data set, there are a number of limitations with these observations I would like to point out. First, sample size is very limited, and I only took one reading at each elevation.  Second, pocket pulse oximeters are not very accurate below oxygen saturation levels of 70%, and ambient light interference (as we experienced at the summits of Rucu Pichincha and Cotopaxi) can interfere with accuracy. Also, the literature suggests that pulse oximetry utility is limited in diagnosis of acute mountain sickness, and that measuring oxygen saturation after light exercise compared to rest may be more predictive of acute mountain sickness. I believe that I did not experience altitude sickness at any point during this trip. I had a mild headache after sleeping above 15,000’ (4572 m), but that resolved once we started hiking up the mountain. We stayed at the summit of Cotopaxi for approximately 1 hr, and while I had a slight headache and was day-dreaming (more than usual), I felt pretty good overall and had no problems on the descent. Pulse oximetry is painless and non-invasive, and can be a useful tool in evaluating respiratory and other complaints at high altitude, but care should be taken to minimize erroneous measurements to avoid misinterpreting the data.

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, and would appreciate any tips on how to accomplish this!

High Altitude, Medicine, Mountaineering

La Paz: Healthy Living At 12,000 feet

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Dr Gustavo Zubieta-Calleja explains how lessons learned in La Paz can make space exploration easier

I just returned from the “Chronic Hypoxia” conference in La Paz, Bolivia at 12,000 feet elevation (3,640 m). The sponsor and organizers were Drs. Gustavo Zubieta-Calleja and his daughter Natalia Zubieta De Urioste who run the Institute of High Altitude Pulmonology and Pathology there. Presenters and attendees came from 16 countries covering topics ranging from molecular biology to genetics.
Dr. Zubieta previously published a scientific analysis of centenarians living at various altitudes. He compared Santa Cruz, Bolivia, at sea level, with La Paz/El Alto, each with populations of over three million, and found there are eight times more people over 100 years old at high altitude. (BLDE University Journal of Health Sciences, see blog post 1/5/18) Since his father Gustavo Zubieto Castillo founded the institute in 1970, they have been advocates of the health promoting effects of a low oxygen environment.
A presentation on “BioSpaceForming” even identifies chronic hypoxia as a “fundamental tool”, that “gives humans and other species an advantage on earth and beyond.” Dr Zubieta explained that the space station is engineered to have the barometric pressure (760 mmHg) and oxygen content of sea level. When the astronauts change into their space suits to work outside the ship they experience a pressure drop of over 200 mm Hg in a laborious process of donning the suit. Seeing that millions of inhabitants are healthy at 486 mm HG in Bolivia, he advocates that maintaining lower pressures and lower oxygen levels in the space station would be economical and promote the health of the astronauts. Several altitude scientists see this as a future that “uncouples biology and physics.

Acclimation, Medicine

Life Threatening Causes of Low Oxygen At Altitude

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Anyone who travels to areas of high altitude is at risk for high altitude pulmonary edema (HAPE). Classic HAPE symptoms include a dry cough and shortness of breath with activity; leading eventually to trouble breathing at rest. If left untreated, serious complications can occur. Many other conditions can mimic HAPE, and it is crucial for health care professionals to be able to distinguish between HAPE and other disorders that may cause similar symptoms. Illnesses that may present similarly to HAPE include pneumonia, a blood clot in the lung (pulmonary embolism), and chronic obstructive pulmonary disease (COPD) or asthma. Your health care provider will take a thorough history, but the following outlines the differences between HAPE and other similarly presenting conditions.

  • Pneumonia: In both HAPE and pneumonia, shortness of breath, fast breathing, and a fever occur. Normal oxygen saturations are above 90%, and if you have HAPE or pneumonia, these could be as low as 60 %. However, if you have pneumonia, you will feel a lot worse than if you have HAPE. HAPE typically responds to high flow oxygen and you will get better over a few hours. Whereas if you have pneumonia with low oxygen saturations, you will need immediate hospitalization.
  • COPD/Asthma: High altitudes may exacerbate your COPD or asthma. How providers tell the differences is through something called pulmonary function tests. This tests how well your lungs work. Your provider will have you breath into this device before and after being given albuterol. If your lung tests improve after the albuterol, then COPD or asthma are the more likely diagnosis. It is important to tell your provider if you have a history of COPD or asthma, and if you are a current or former smoker.
  • Pulmonary Emboli (PE): Patients with a blood clot in their lung typically have the same symptoms as HAPE but will sometimes also have chest pain when taking deep breaths. You may also have blood in your sputum and/or calf pain or swelling. You are more at risk for a PE if you have had a recent orthopedic surgery (such as a hip or knee replacement), you have an irregular heart rate, have a clotting disorder, smoke, or are on birth control. If you have these risk factors and additional symptoms, your provider may order a lab test called a d-dimer  and a chest CT scan to help distinguish between a blood clot or HAPE.

If you are experiencing any of these symptoms, it is important to go see a health care provider immediately. A thorough history and exam will help aid in the correct diagnosis and prevent any potential complications. And most importantly, will help you get back on track to enjoy your high-altitude vacation and living!

Miranda Bellantoni, FNP-Student

  1. Luks AM, Swenson ER, Bärtsch P. Acute high-altitude sickness. Eur Respir Rev 2017; 26.
  2. UpToDate. Distinguishing HAPE from Pneumonia 2018.
  3. Brusasco V, Martinez F. Chronic obstructive pulmonary disease. Compr Physiol 2014; 4:1.
Child Growth & Development

Newborns at altitude: less breathing problems, higher chance of brain hemorrhage

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The September 2018 issue of the Journal of High Altitude Medicine and Biology has an article reviewing statistics on newborn health in the Mountain Census Division: AZ, CO, ID, MT, NM, NV, UT and WY.  The lead author, Robert Levine and his coauthors found that newborns in this region have “by far the lowest infant mortality rates for respiratory distress.”  Conversely, there is a higher incidence of intraventricular hemorrhage, or bleeding in the brain, not caused by trauma. This can be a complication of prematurity.

The authors analyzed about 70 million births and 12,000 deaths in over 3000 counties between 2007-2015. They compared maternal education, age, and marital status. The mean elevation of the mountain division counties is 5,725 feet, with the mean for the rest of the US being 2,500 ft. Colorado ranges from a low of 3317 ft to 14440 with a mean of 6800 ft. There were 30 counties above 8000 ft.

Their conclusion :”…we believe the most plausible interpretation of the present data is that they raise questions abut whether maternal residnce at high altitude has uniformly adverse health effects on infant mortality.”

In other words, maybe it’s not all that bad to live in the mountains!

Information and discussion for visitors and residents at high elevations.