Category Archives: Acclimation

What happens to your body’s physiology when you move between low and high elevations?

Facing the COVID-19 Pandemic in the Mountains During the Winter

Ski resorts have opened in Colorado, and with more holidays around the corner, it is essential to remember that we are still currently amid a pandemic that is surging with cases here in Colorado. So what does that mean for those that live in the mountains and at altitude?

When it comes to the coronavirus, there are advantages and disadvantages to living at altitude. While research does show that COVID-19 has a more challenging time affecting mountainous populations, Summit County, Colorado has its own set of dangers. With the influx of skiers, travelers, and increased indoor activities, it is essential to remember how to protect yourself and your neighbors here in Summit. 

Research shows that populations living at higher altitudes are at less risk of transmission and have better adaptations to hypoxia than those living at lower altitudes (Pun et al., 2020). Interestingly, people living in high altitude environments live in a state of hypoxia or lower oxygen levels, and the lungs of these people generally adapt to conditions of decreased oxygenation. However, this has not been proven to be a saving grace, especially if the person has comorbidities like asthma, hypertension, diabetes, kidney disease, or COPD. Research has also shown that the environment is often colder and drier at higher altitudes with increased UV radiation, which can help slow the spread of the virus. However, this is only relevant when you are outside and does not diminish its spread indoors. While all these facts are unique to living at altitude, we must remember that Summit County is a tourist destination, is densely populated and requires the utmost protection despite these factors. 

So how do you protect yourself this upcoming winter in the mountains? With ski resorts initiating strict policies and physical distancing, what are ways that we can help keep these businesses and resorts open?

Some might blame the tourist for bringing COVID to the mountains; however, the increase in numbers can be tracked down to Summit County residents spreading it to one another through social events and large gatherings. It is important to remember to wear a mask, stay at home whenever possible, wash your hands if you feel sick, get tested, isolate, and make sure to get your flu shot.  It is essential to listen to public health orders as they change throughout this second surge of COVID-19 infections. Going into the holidays, the CDC recommends not traveling to see your family and only celebrating the holidays with family members that live in your house. It is essential to stay vigilant as we go into the winter months so the mountain communities can stay safe. 

COVID-19 Information 

What are the symptoms of COVID-19?

  • Fever
  • Cough
  • Body Aches
  • Chills
  • Shortness of Breath
  • Headache
  • Loss of taste or smell
  • Congestion
  • Sore Throat
  • Nausea/Vomiting
  • Diarrhea

When do I seek emergency help?

  • Trouble breathing
  • Pain or pressure in chest
  • Inability to stay awake or awaken
  • Blue colored lips or face
  • New confusion

Where do I get tested in Summit County?

  • Community Testing Site
    • Where: 110 Third Ave. Frisco, Colorado
    • When: 8 a.m.-5 p.m. Monday through Friday
    • Who: Asymptomatic and symptomatic individuals
    • How: email summitcovidtesting@vailhealth.org with the information below –
      • Name
      • Phone Number
      • Picture of Photo ID (not necessary if you don’t have one)
      • Front/Back pictures of insurance card (not necessary if you don’t have one)
  • Centura Health Community Testing Site
    • Where: Summit Vista Professional Building 18 School Rd. Frisco, Colorado
    • When: 9 a.m.- 2 p.m. Monday-Friday & 9 a.m.- 12 p.m. Saturday-Sunday
    • Who: Asymptomatic and symptomatic individuals
    • How: Call 970-668-5584 to receive testing referral. 
  • Summit Community Care Clinic
    • Where 360 Peak One Dr., Frisco, Colorado, First Floor, Summit County Medical Office Building, Suite #100.
    • When: Tuesday, Wednesday, Friday during business hours
    • Who: SCCC patients or establish care with SCCC
    • How: Call 970-668-4040 to schedule an appointment
  • Mako Medical Community Testing Site
    • Where: Silverthorne Recreation Center overflow parking lot, 464-478 E Fourth St., Silverthorne, CO 804898.
    • Who: Asymptomatic and symptomatic
    • How: No appointment necessary, will need to complete registration at site or before online. 

Summit County updated testing information: https://summitcountyco.gov/1324/Testing

Caitlin Endly is a Texas transplant that has lived in Denver, Colorado for the past three years going to school to become a Family Nurse Practitioner at the University of Colorado. She has been a Registered Nurse for five years and currently works as a Neuro Trauma nurse at St. Anthony’s Hospital in Denver. She graduated with her Bachelor’s of Science in Nursing from Texas State in San Marcos, Texas and has worked as a neuroscience nurse since graduating. In her free time she likes to dance, snowboard, and listen to live music. 

Your Baby or Child Is On Oxygen

This is a handout distributed by Dr. Christine Ebert-Santos, MD, MPS, at Ebert Family Clinic, Frisco, Colorado.

Living at high altitude is a challenge for our bodies. The amount of oxygen in the air we breathe is less the higher you go. Since we all need oxygen to live, this can cause problems.

There are three times when oxygen may be needed by children living at altitude:

  1. During the newborn period;
  2. When a child has a respiratory illness, even a mild cold;
  3. During the first 48 hours after returning/arriving from sea level.

When a baby takes their first breath, the higher oxygen level in the air sets off many changes in the heart, lungs and blood vessels around the lungs that convert the child’s respiratory system from transferring oxygen from the placenta to the lungs. Exposure to a low oxygen environment during the first few weeks can interfere with the normal fall in the pressures of the blood vessels in the lungs and closing of the vessels that shunted blood away from the lungs in the womb.

In babies and children, we are not worried about brain damage from lack of oxygen due to the altitude. Don’t panic if the oxygen cannula falls off during the night or the tank runs out. The problems caused by the low oxygen saturations (usually running between 78 – 88%) seen at altitude develop over days, weeks or years, due to changes in the heart and lung. Hypoxia, the term for low oxygen in the blood, causes constriction, or narrowing, of the blood vessels in the lungs. This can lead to back pressure on the lungs and heart, which may cause fluid to leak into the air sacs in the short term or abnormal increases in the heart muscle in the long ter.

Rarely do babies or children with low oxygen levels at altitude show symptoms. The normal oxygen saturation levels at 9000′ are about 92 – 93%, and can be 89 – 90% in healthy people. We start treating with oxygen below 89%, even though symptoms like trouble breathing, fast breathing, poor sleep, or poor color are unusual until the saturation level is in the 70’s.

It is important to understand that oxygen is prescribed by your doctor to treat symptoms of altitude sickness such as headache, vomiting and trouble breathing, and to prevent more severe symptoms from developing. A small percent of persons with mildly low oxygen levels will suddenly, over a few hours, go into full-blown pulmonary edema where their lungs fill with fluid, they have much more trouble breathing, and turn blue. This is a life threatening emergency.

When you arrive home with your child on oxygen, be sure and call the respiratory therapist at the phone number on the tank so they can come to your house and teach you about the equipment. Don’t feel discouraged if your toddler or young child is fighting the oxygen at first. They will usually adjust and accept the cannula in about 30 minutes.

Paraguay Takes On Colorado’s Fourteeners

After a horrendous Autumn of forest fires in Colorado, we’ve received well over a foot of snow in a series of storms, and it’s safe to say Winter has arrived. Hiking season is never truly over in the Rockies, but Colorado’s famed Fourteeners are now blanketed in snow, increasing the risk of any attempted ascent exponentially. But through the fire and ice, the Summer yielded ample opportunity for at least one enthusiast to check off more of her bucket list adventures.

Since leaving her home in Paraguay, mountaineer and hiking expert Clarissa Acevedo Santos has spent over a decade ascending Colorado and Hawai’i’s highest peaks. In addition to her excursions in the Ko’olau and Kahalawai ranges including Maui’s Haleakalā crater, she has summited well over half the 58 peaks in Colorado over 14,000 feet, making her the first from her country of record to do so.

She was invited on her first Fourteener years ago when friends took her up Quandary outside of Breckenridge, CO, at 14,271′ (4350 m).

“When I hiked that first mountain, it was hard, because I wasn’t used to gaining that much elevation. I didn’t really enjoy it so much because of how cold it was on the summit. Even though I made it to the top, I wasn’t really having fun with not feeling my lips and not feeling my fingers because it was really, really cold. I could barely smile, and we couldn’t even enjoy the summit because of how windy it was!

“After that hike, I didn’t hike for a while, and I got invited again to climb Mt. Elbert in 2012. It was actually much more enjoyable because it was with a big group of college kids from Summit and the weather was just perfect. We were able to summit it and enjoy the day and have lunch up there. So that’s what started to change my mind about hiking Fourteeners because I enjoyed my time up top. That’s when I realized it’s not always difficult to be up there. I think I got what all the hikers call ‘Peak Fever’. So after that is when I feel like I started going non-stop, and I met more friends that were into hiking, and researched more about the mountain before I go.

“I always go with people who knew more about it, so I started learning more with other friends and other hikers. And I started feeling actually great when I got higher. It was always harder to get started close to the beginning [of the trail], just to gain all that elevation. But then when I was getting close to the summit, I just got more energy. I just got more excited to be at the top. That’s the goal. It’s a great feeling.”

Clarissa has an app that she uses to record all her summits called Colorado 14ers that allows her to keep record of and upload photos from every Fourteener she’s hiked. She pulls it up as she recounts year after year of more and more summits, some she’s even done more than once.

There is a class system rating every trail by level of difficulty, Class 1 being the easiest and Class 4 being the most difficult. The most difficult peak Clarissa recounts climbing is Long’s Peak, as well as the most dangerous weather she’s climbed in.

“It was a little bit late to summit it. It was not a good idea. If the rocks got wet, it could be very dangerous. There were people turning around. We decided to wait on a ridge. There were three [of us], and one turned around. He wasn’t feeling good, he was getting tired, he wasn’t used to hiking that many hours.

“We decided to wait for the clouds to go away. After that we just kept going. It did not rain on us, thankfully.”

Clarissa has seen her share of altitude sickness as well. One of her frequent hiking companions repeatedly gets stomachaches and headaches everytime they hike, in spite of being an experienced hiker as well.

“I always ask [one of my friends in particular] if she wants to stop or if she wants something. She normally doesn’t eat before she starts a hike. No breakfast. But I also carry ginger candy … I learned that from other hikers telling me it can help settle your stomach a little bit. It’s everywhere, in all the stores. Now they’ve created gums. I’ve started chewing them on my hikes just in case. You never know. I’ve seen people who hike all the time, and they ate something that didn’t digest well, and they feel sick and get a little dizzy.

“I’ve never experienced any headaches on the way up. The only time I remember having a headache is when I ran out of water. I hiked Oxford and Belford in the Saguache range in the same day. My head hurt and it lasted for that night. Now I take a filter with me so I can fill my [Camelbak] bladder. And I also take electrolytes. And I’ve started hiking with poles more as well, just because you put alot of weight on your knees when you’re hiking down. It’s very smart to start using poles.”

When it comes to preparing such demanding ascents, Clarissa recommends spending some time at an intermediate altitude before hitting the trail, and staying well-hydrated. Caffeine and alcohol the night before doesn’t typically help.

Clarissa with her husband on their way up Mt. Shavano in September 2019.

“It doesn’t matter how fit you are … you can still get really sick. I’ve heard of people who get headaches for several days because [they’re] not used to [the elevation here].”

She also says it’s important that you start any hiking at all to build the strength in your lungs.

“It does hurt,” she says about the stress on your respiratory system. “I remember when I was hiking Quandary, my chest was so pressed, my heart was [beating] so fast, my stomach was feeling weird, like I had to pee or I had to do number two or something. It was such a difficult part of … gaining all that elevation.”

“You’ve gotta find a good pace for yourself. I see many of my friends going really fast ahead of me, then they’re very tired and they have a hard time getting to the top. I’ve waited for many people because they are struggling so much at the end. Take as many breaks as you think [you need]. Carry enough water!

Clarissa keeps seeing a lot of hikers running out of water. “They just bring a tiny plastic bottle. That’s a huge mistake. And bring food, too. You will get hungry after a mountain. It’s so funny how many people are unprepared. If I’m hiking with newbies, I make sure they have everything, and they’re always thankful.”

When it comes to clothes and shoes, Clarissa recommends really good traction. She’s tried some more affordable brands, but says the durability is worth paying more for.

Don’t ever hike in new hiking shoes before you’ve broken them in. Good hiking socks also have more padding at the heels and toes and help prevent blisters. She also will double-up on socks, or even bring an extra pair to help mitigate possible cold.

“I reapply sunscreen on my hikes two to three times. Many times my nose will burn. I always carry sunglasses. You’re so close to the sun, you don’t realize. You don’t want to burn your eyes or your face. Even with the sunglasses, having a hat on top of it doesn’t hurt. Even in the Summer in the mountains, carry additional gloves or layers, because you don’t know what the weather could be. Temperature changes quick.

“I just recently purchased a nice puffy Northface that helped me. I will always have a thin layer underneath because you get hot and cold. You’re gaining elevation, you get hot, then you get cold in the middle …”

When it comes to navigation, Clarissa’s main resource is 14ers.com, which allows you to download offline maps, so you aren’t relying completely on having cell service.

“Even though I have hiked many of them, I want to be sure I’m going the right direction … I just love reading everything I can beforehand. I read about the class, how much exposure, how long it’s going to take, then I download the maps, look at the maps, what kind of road it’s going to be, if my car can make it up higher or if I have to hike longer.”

Clarissa has heard of other Paraguayans hiking around the world, but has never met another one on a Fourteener personally. But she does meet a lot of people from around the world on these ascents who ask if there are mountains in Paraguay. The highest is Cerro Peró at 2762′ (842 m) in this landlocked country known more for its rivers and the hydroelectricity they provide for Paraguay and its neighboring countries, including Brazil and Argentina.

Clarissa says she’s learning more and more each year about mountaineering and advocates learning as much as possible about each ascent before you go. The weather may be different every single time.

Bring the layers, whether you think you’ll need them or not. And leave no trace.

Thank you, Clarissa, for sharing your continuing legacy, and be safe up there!

robert-ebert-santos
Powder ‘stache.

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. Clarissa is his wife who is increasingly a much faster, more experienced mountaineer than he is, but he will occasionally feel ambitious enough to join her on a Fourteener, at the top of which they both enjoy a delicious cider, weather permitting.

Acetazolamide

Typical symptoms of acute mountain sickness (AMS) are headache, loss of appetite, disturbed sleep, nausea, vomiting, fatigue, and dizziness. However, more serious conditions such as high altitude pulmonary edema (HAPE) or cerebral edema (HACE) can present with this illness. Avoiding these unpleasant symptoms while at elevatione is possible through gradual pre-acclimatization when possible (what science recommends!), or there are specific medications that can potentially prevent the development of AMS, such as acetazolamide. This article will address how acetazolamide (also known as Diamox) can help prevent AMS, discuss the physiological effects of the medication, some side effects, and whether or not this drug can enhance physical performance.

 How does it work?

Acetazolamide is a carbonic anhydrase inhibitor. Carbonic anhydrase regulates kidney absorption of sodium bicarb and chloride. Acetazolamide works by inhibiting carbonic anhydrase, preventing the reabsorption of sodium bicarb and chloride, causing acidosis in the blood. When experiencing AMS, the body is in a state of respiratory alkalosis. By taking acetazolamide, which causes metabolic acidosis it drives receptors in the body to increase the patient’s minute ventilation by as much as 50%, improving arterial PO2 and increasing oxygen saturation.

How can I obtain acetazolamide and when should I start taking it?

Acetazolamide requires a doctor’s prescription, and the typical dose for the prevention of AMS is 125 mg twice daily. The typical recommendation is to start taking acetazolamide one day before your exposure to high altitude and continue usage throughout your trip. When taken one day before exposure, studies show that acetazolamide reduced AMS incidence and enhanced tolerance to submaximal exercise on the first day at high altitude versus starting administration the day of arrival.2 However, if, for some reason, the medication isn’t started a day before arrival to high altitude, then the medication should be started upon arrival, which still shows a decreased incidence in the development of AMS. 

Allergies & Side Effects

Acetazolamide belongs to a classification of drugs known as sulfonamides, which is broken down further into two categories: antibiotics and nonantibiotics. Acetazolamide is considered a nonantibiotic sulfonamide, which varies significantly from sulfonamide antibiotics because these antibiotics contain what is known as an arylamine group in their chemical structure. This arylamine group is a key component of the allergic response to sulfonamide antibiotics (sulfamethoxazole, sulfasalazine, sulfadiazine, and the anti-retrovirals amprenavir and fosamprenavir); however, this structure is not present in other sulfonamide drugs like acetazolamide.1 There is available evidence that suggests patients who are allergic to arylamine sulfonamides do not cross-react to sulfonamides that lack the arylamine group and so may safely take non-arylamine sulfonamides.1 Patients with known allergies to sulfonamide drugs should consult with their healthcare provider before taking acetazolamide.

Like all other medications, there are risks that side effects will occur with acetazolamide’s administration. The common side effects are fatigue, malaise, changes in taste, paresthesia, diarrhea, electrolyte disorders, polyuria, and tinnitus. While conducting research, I found 3 – 4 people from my hometown, located at 69 feet above sea level, who have taken acetazolamide while rapidly ascending to 8,000+ feet to ski or hunt. When asked how their experience was taking acetazolamide, the common response was that they stopped using it within the first two days due to the change in the taste of their beer! The pleasurable “fizz” in our carbonated drinks is attributed to chemical excitation of nociceptors in the oral cavity via the conversion of CO2 to the carbonic acid in a reaction catalyzed by carbonic anhydrase. So administering a carbonic anhydrase inhibitor like acetazolamide results in flat-tasting carbonated drinks, or, as described by the aforementioned subjects, a “nasty beer”!4 While a bad tasting beer is no fun, AMS is a lot less fun, and one would be best advised to continue taking acetazolamide while at high altitude.

Can taking acetazolamide increase physical performance and endurance at high altitudes?

Though enticing, it doesn’t seem to work out that way. There are multiple studies on exercise endurance in hypoxic conditions with the administration of acetazolamide, but the produced results are confounding. The majority of the studies show that for a non-acclimated person taking acetazolamide in hypoxic conditions, endurance and exhaustion time were increased with submaximal and maximal exercise. A few reasons this may be true are the induction of metabolic acidosis and its effects on muscle cells, the diuretic effect of the drug inducing dehydration, and additional increases in work of breathing cause vasoconstriction in locomotor muscles, which can impair exercise performance.3 Regardless, this medication’s proven science in the prevention of AMS should not be mistaken with the multiple confounding studies on exercise endurance.

Scott “Scotty B” Rogers, FNP-S

From Opelousas, Louisiana, Scott Rogers is currently a Family Nurse Practitioner student at Walden University after having practiced five years as an RN following his BSN from the University of Louisiana at Lafayette. He has lived in Colorado for the past four years where he enjoys hiking with his wife and dog, snowboarding all the resorts in Summit County, and basketball, and hopes to pursue more work with acute physical rehabilitation, orthopedics, and sports medicine.

References

1. American Academy of Allergy Asthma & Immunology. (2019, June 23). Acetazolamide and sulfonamide allergy: AAAAI. Retrieved November 13, 2020, from https://www.aaaai.org/ask-the-expert/acetazolamide

2. Burtscher, M., Gatterer, H., Faulhaber, M., & Burtscher, J. (2014). Acetazolamide pre-treatment before ascending to high altitudes: when to start?. International journal of clinical and experimental medicine, 7(11), 4378–4383.

3. Garske, L., Medicine, 1., Brown, M., Morrison, S., Y, B., G., B., . . . Zoll, J. (2003, March 01). Acetazolamide reduces exercise capacity and increases leg fatigue under hypoxic conditions. Retrieved November 13, 2020, from https://journals.physiology.org/doi/full/10.1152/japplphysiol.00746.2001

4. Jean-Marc Dessirier, Christopher T. Simons, Mirela Iodi Carstens, Michael O’Mahony, E. Carstens, Psychophysical and Neurobiological Evidence that the Oral Sensation Elicited by Carbonated Water is of Chemogenic Origin, Chemical Senses, Volume 25, Issue 3, June 2000, Pages 277–284, https://doi.org/10.1093/chemse/25.3.277

A conversation with Dr. Chris on neonatal oxygen levels at elevations 9000’ and above

My name is Austin Ethridge, I am a physician assistant student from Red Rocks Community College PA program who has been fortunate enough to have completed my pediatric rotation with Dr. Chris in Frisco, Colorado, this month. Dr. Chris has extensive experience providing care to the pediatric residents of Summit County, having established her practice here in 2000, following 20 years as a pediatrician on Saipan, in the Northern Mariana Islands, southeast of Japan. She has a unique perspective on high altitude health, having transitioned from sea level to the 8000′ and above elevations unique to Summit County. Since moving here, she has been advocating for more in-depth medical research regarding the needs specific to these high-altitude communities. We are here in her office today at the Ebert Family Clinic to discuss neonatal oxygen use in Summit County.

Dr. Chris, based on your experience, why do neonates need oxygen at a higher elevation? Is it because they need to acclimate?

Yes, that’s basically it, and smaller lung size at birth.

Yes, that’s what I read. Basically, the maternal physiology compensates for the higher altitude. When the infant is born, their lung size and physiology need to catch up to the altitude.

Based on your practice, when do you place neonates on oxygen?

Usually at 89% or below, but you see, that’s just it. Many parents ask why their children need to be on oxygen when neither themselves nor their siblings were on oxygen. One of the primary reasons that this has become more of an issue is the less invasive methods of measuring oxygen saturation in the blood. Before the 1990s, the only time to measure oxygen saturation in a newborn was if a concern for illness or pulmonary problems existed, which was completed by obtaining an arterial blood gas, a very invasive procedure. Do you know at what oxygen saturation level we begin to detect cyanosis in neonates?

Around75%, which means before the pulse oximeter used today, we had no idea if the infant’s oxygen saturation was in the 80s! Now that we have the pulse oximeter, we have access to so much more information. And this is why it is essential to determine the normal oxygen levels for these infants at higher elevations.

Does this include cyanosis or blue discoloration of the hands and feet, or is it just central as in the face and chest?

The blue discoloration of legs and arms do not count; this is very common and not concerning, only the discoloration of the trunk and face.

Yes, based on the articles that I have been reading while I have been here, there are not many studies that reflect normal oxygen saturation in neonates at a higher elevation. Most of the articles that I did find determined that newborn oxygen saturation is lower at elevations of around 6000’, with average values within the range of 89-96% SpO2 compared to greater than 97% at sea level. However, there could be a significant difference between 9000’-10000’ feet and the 6000’ in these studies.1-3

That is exactly right, and that is why I want to do a study here in Summit County to determine the average oxygen saturation at these altitudes.

On average, how many newborns do you place on oxygen in Summit County?

About 40% of newborns are placed on oxygen due to low oxygen levels at birth, and I would say that less than 5% will still need oxygen after their two-week visit; however, this rate may be higher in those that live at elevations of 10,000′ or greater. In general, studies have observed that the lowest oxygen levels tend to occur around the 4th day of life and then improve from this point onward. What is the main complication that we are worried about in infants that have low oxygen levels?

Pulmonary hypertension. At birth, when the fetal circulation is shunted back through the lungs, the pulmonary pressure decreases to allow this to happen. If the oxygen levels are too low, the vessels in the lungs may not dilate enough, and this could lead to elevated pulmonary pressures. I read an interesting study that found increased pulmonary pressures in Tibet children as measured by ECHO cardiogram until the age of 14. These pressures were noted to increase with increasing elevation but to decrease with increasing age. Generally, by the age of 14, the pulmonary pressures had normalized; the authors considered this to be a normal physiological response. However, it is worth noting that these children in the study came from generations of individuals that have always lived at these altitudes.4-5

That is correct. That is the difference between adaptation and acclimatization. Many of the children that live up here are acclimatized, meaning that their bodies have adapted on a physiological level, but their genetics remain the same. However, adaptation is observed in many families that have lived at high elevations for generations; in these instances, the changes have occurred at the genetic level.

That makes sense; so the data from some of those studies may not directly apply to the population here.

That is correct. Are we worried about brain damage in this setting of low blood oxygen levels?

No, I do not think so.

We are not! In fact, as an example of this: when I was in Saipan, there was a child that had a cyanotic, congenital heart defect that was unable to be repaired for social reasons. This child always appeared blue, and his oxygen saturation would have been very low. He did just fine in terms of development and progress in academics. There were no signs of developmental delay or any other neurological problems at all.

Are there any resources you recommend for parents whose newborn may need to be on oxygen?

Yes, I have a handout that I provide to all families whose infants are on oxygen. (View Dr. Chris’s handout here.)

Are there any red flags or signs that the newborns’ oxygen may not be high enough when they are sent home? Is there anything parents should look out for? I know that you mentioned the oxygen level needs to be as low as 75% before there are any signs of concerning central cyanosis.

No, there really are no clinical signs. A company called Owlet produces a sock for the newborn’s foot that monitors oxygen saturation. I am not sure how accurate this is, but if the parents really want to do something to monitor the oxygen level, this could be a way to do so. It is pretty expensive. On an aside, we are currently in communication with this company regarding future opportunities to conduct research using their product with regards to newborn oxygen saturation at higher elevations, so stay tuned for more developments on this topic.

Are there any risks to starting the infant on oxygen?

No, not at the level that these newborns are sent home on. In premature infants, there is a risk associated with oxygen therapy for eye and lung disease. However, these premature infants are placed on very high flow rates and positive pressures. The damage is actually caused by the pressures of the oxygen being too high. This is not the case for the newborns that we place on oxygen.

Are there any risks to infants or children growing up at high altitude?

Yes, there is some evidence of a very slight increased risk of pulmonary hypertension, but this is very rare.

Thank you so much for taking the time to discuss this, Dr. Chris!

References

  1. Ravert P, Detwiler TL, Dickinson JK. Mean oxygen saturation in well neonates at altitudes between 4498 and 8150 feet. Adv Neonatal Care. 2011 Dec;11(6):412-7. doi: 10.1097/ANC.0b013e3182389348. Erratum in: Adv Neonatal Care. 2012 Feb;12(1):27. PMID: 22123474.
  2. Morgan MC, Maina B, Waiyego M, Mutinda C, Aluvaala J, Maina M, English M. Oxygen saturation ranges for healthy newborns within 24 hours at 1800 m. Arch Dis Child Fetal Neonatal Ed. 2017 May;102(3):F266-F268. doi: 10.1136/archdischild-2016-311813. Epub 2017 Feb 2. PMID: 28154110; PMCID: PMC5474098.
  3. Bakr AF & Habib HS, Normal Values of Pulse Oximetry in Natewborns at High Altitude. Journal of Tropical Pediatrics 2005; 51(3) 170-173.
  4. Qi HY, Ma RY, Jiang LX, et al. Anatomical and hemodynamic evaluations of the heart and pulmonary arterial pressure in healthy children residing at high altitude in China. Int J Cardiol Heart Vasc. 2014;7:158-164. Published 2014 Nov 12. doi:10.1016/j.ijcha.2014.10.015
  5. Remien K, Majmundar SH. Physiology, Fetal Circulation. [Updated 2020 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539710/
  6. Thilo EH, Park-Moore B, Berman ER, Carson BS. Oxygen Saturation by Pulse Oximetry in Healthy Infants at an Altitude of 1610 m (5280 ft): What Is Normal? Am J Dis Child. 1991;145(10):1137–1140. doi:10.1001/archpedi.1991.02160100069025

Austin Ethridge is a second-year physician assistant student at the Red Rocks Community College Physician Assistant Program. Originally from the Colorado front range, Austin attended the University of Northern Colorado where he obtained both a bachelors and masters degree in chemistry prior to attending PA school. In his free time, Austin enjoys spending time with his friends and family, reading, and cycling.

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. 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!

COVID-19 Update: A Look at How the World’s Highest Altitude Populations Have Been Affected

As the gateway to Machu Picchu, the city of Cusco, Peru attracts over 3 million tourists from all around the globe each year. With this many people passing through the city, you can imagine why local residents feared the worst when the COVID-19 outbreak began. However, out of a population of approximately 429,000 people, the city has only four COVID-19 related deaths – three tourists who traveled to the area and one native with previous risk factors.

Machu Picchu

Machu Picchu, a UNESCO World Heritage Site, brings 3 million tourists from around the world to the Cusco region of Peru every year.

One death out of 196 confirmed cases for the city makes for a remarkably low fatality rate of 0.5% for the native population. Peru as a whole has a fatality rate closer to 3% with over 6,000 deaths, making it one of Latin America’s most affected countries. Many believe the fatality rate to be even higher as testing has not become widely available in the country.

To understand why Cusco is such an outlier when compared to the rest of the country, there are several factors to take into consideration. One of those factors that researchers haven’t quite been able to figure out, but believe plays a role, is altitude. The Cusco region of Peru sits at 11,152 ft elevation compared to the capital city of Lima that sits at only 512 ft elevation.

Research comparing the high-altitude regions of Tibet, Bolivia, and Ecuador has revealed similar trends. A study completed April 22, 2020 and published in the June 2020 scientific journal “Respiratory Physiology & Neurobiology” indicates that populations living above 9,842 feet elevation reported significantly lower levels of COVID-19 cases than populations living at lower elevations. The research showed the infection rates in the Andes Mountains of Bolivia were one third the infection rates the rest of Bolivia, and the infection rates in the Andes Mountains of Ecuador were one fourth of the rest of Ecuador. In both Bolivia and Ecuador, the areas with the highest concentration of COVID-19 cases were located at an elevation close to sea level.

At an elevation of 11,942 ft, La Paz, Bolivia is the highest capital city in the world.

Why populations living at higher altitudes are experiencing lower infection rates is still not well understood, but there are a few theories at play. It is hypothesized that people living at altitude are able to live in a state of chronic hypoxia, or a state of chronically low oxygen in the blood. Hypoxia is one of the conditions caused by COVID-19, and if a person’s body is already used to low levels of oxygen, their symptoms may not be as severe. There are other environmental considerations at altitude that may shorten the life-span of the COVID-19 virus, including high levels of UV radiation that can kill the virus, low barometric pressure that does not support the weight of the aerosolized droplets that the virus lives in, and dry thin air that does not support the transmission of aerosolized droplets.

However, as intriguing as the effect of altitude on COVID-19 statistics is, it is important to note that there are several other proven factors that come into play when looking at these populations. First, most high-altitude towns and cities tend to be rural. When population density per square mile drops, the rate of transmission of infectious diseases also drops – rural settlements allow for natural social distancing. Second, populations living at higher altitudes have lower rates of obesity and generally have better overall health. Living at high altitude causes a reduction in the hormones that signal hunger, leading to consumption of fewer calories. Additionally, completely normal daily activities in a state of chronic hypoxia due to low levels of available oxygen in the air raises the body’s resting metabolic rate, leading to burning more calories. The healthier a person is prior to contracting an illness, the more likely their body is to be able to fight it off successfully.

Research regarding how altitude affects COVID-19 transmission, infection, and recovery rates is ongoing. It may be too soon to tell exactly why or how altitude comes in to play, but early findings are suggesting that now is a great time to be a resident of the great Rocky Mountains – but then again, when is it not?

References

https://www.washingtonpost.com/world/the_americas/coronavirus-andes-peru-ecuador-bolivia-tibet-high-altitude/2020/05/31/0b2fbf98-a10d-11ea-be06-af5514ee0385_story.html

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7207123/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175867/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5094724/

https://en.wikipedia.org/wiki/Machu_Picchu#/media/File:80_-_Machu_Picchu_-_Juin_2009_-_edit.2.jpg

https://en.wikipedia.org/wiki/Machu_Picchu#/media/File:80_-_Machu_Picchu_-_Juin_2009_-_edit.2.jpg

Megan Schiers is a 3rd year Physician Assistant student studying at Midwestern University in Glendale, AZ. She graduated from Idaho State University in Pocatello, ID with a Bachelor of Science in Dental Hygiene and worked as a dental hygienist in Strasburg, CO for two years prior to starting PA school. She is passionate about increasing access to healthcare in rural areas and hopes to specialize in emergency medicine or cardiothoracic surgery following graduation this fall. During her six weeks in Frisco, CO, she has enjoyed hiking in the beautiful mountains, camping at Camp Hale Memorial, visiting Maroon Bells, and checking out Black Canyon of the Gunnison National Park.

COVID in Colorado Update: Reasons high altitude residents may be less susceptible

Last week we were privileged to have a Zoom discussion with two high altitude experts from the Instituto Pulmonar Y Patologia de la Altura (IPPA) founded in La Paz,  Bolivia in 1970. Dr Gustavo Zubieta-Calleja and Dr. Natalia Zubieta-DeUrioste answered our questions about their recently published article, Does the Pathogenesis of SAR-CoV-2 Virus Decrease at High Altitude?. They and the seven  coauthors presented data comparing COVID cases in high altitude areas of China, Bolivia and Ecuador showing a marked reduction in numbers compared to low altitude areas in the same countries, with dramatic, colorful topographic maps.

Drs. Zubieta-Calleja and Zubieta-DeUrioste and their colleagues theorized four reasons why altitudes above 2500 m could reduce the severity of the corona virus. (Note: Frisco, CO is at 2800 m, Vail 2500 m). As described in their previous paper published in March, the intense UV radiation at altitude as well as the dry environment likely reduce the viability of the virus in the air and on surfaces.

Dr. Zubieta-Calleja on a Zoom chat with Dr. Chris explaining a chart comparing UV exposure in La Paz, Bolivia (top line) and Copenhagen, Denmark (bottom line).
Dr. Chris with Dr. Gustavo Zubieta-Calleja and other altitude experts from the Hypoxia Conference in La Paz on the Camino Chacaltaya, which reaches an elevation of 17,785’/5421 m.

The low barometric pressure causes air particles to be spaced more widely, which would also decrease the viral particles inspired with each breath, reducing the severity and frequency of infections.

Furthermore, residents accustomed to chronic hypoxia may express reduced levels of angiotensin converting enzyme 2 (ACE2) in their lungs and other tissues. This enzyme has been found to be the entry path for the corona virus into cells where it replicates. Finally, the normal adaptation and acclimatization of populations with prolonged residence above 2500 meters may reduce the severity of the disease in individuals, and reduce mortality. This includes increased ventilation, improved arterial oxygen transport, and higher tissue oxygenation mediated by increased red blood cells produced under the influence of erythropoietin, which could be explored as a possible therapy.

Dr. Zubieta-Calleja with statistics reflecting the number of COVID-19 infections at different elevations in Bolivia. Note the most infections occur at a lower elevation.

As we stated in our interview quoted in the Summit Daily News March 17th, none of these factors can be relied upon to protect every individual. Therefore it is important to continue frequent hand washing, wearing masks, social distancing, and avoid touching your face.

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.