Category Archives: Child Growth & Development

Children grow and develop differently at high altitudes than they do at sea level

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. 

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. 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!

Mountain Kids are Smaller

How does living at high altitude affect the human body? It’s a complicated question that researchers have been trying to answer for years.

It takes two things to grow: adequate nutrition and the body’s ability to convert calories into energy.  Observations over 20 years at the Ebert Family Clinic suggest that the decreased oxygen levels at altitude may interfere with optimal utilization of calories or decrease appetite and intake in small children.

After opening her pediatric clinic in Frisco, CO in 2000, Dr. Christine Ebert-Santos noticed that children living at high altitude are smaller than average. Dr. Chris and Meredith Caines Pollaro, an occupational therapist with expertise in feeding and growth in children, organized a group for parents of underweight children but did not find any consistent abnormalities. After this, Dr. Chris decided that smaller growth might be a normal pattern for little ones at altitude. The children were otherwise healthy, with nutritional analysis showing adequate intake, and no signs of endocrine or gastrointestinal problems.

Graduate student Aaron Clark reviewing high altitude growth charts with PA student Laura Van Steyn and Dr. Christine Ebert-Santos.

Research on growth in children at altitude is sparse. So, in 2009, Dr. Chris recruited her daughter Anicia Santos to launch a detailed data analysis.  Anicia worked with one of her math professors at the University of Colorado to convert the data into a unique growth chart for altitude which demonstrated the downward shift. Twice the number of infants and toddlers had weights below the 3rd percentile of the World Health Organization growth charts than at lower altitudes. Heights were also decreased. After years of gathering data, Dr. Chris and Anicia are getting ready to share their findings with the help of Logan Spector, PhD and graduate student Aaron Clark.

Spector, chairman of the department of epidemiology at the University of Minnesota, was concerned about his two nieces who lived in Summit County who were not fitting into the “normal” growth pattern. This sparked his interest in Dr. Chris’ research. He was able to recruit Clark to take on the project.

In the first study of its kind in North America, the growth charts of 970 kids living in Colorado’s high country are analyzed. With over 9,000 pieces of data, one thing is clear. From birth to 18 months of age, children living at altitude weigh much less than the average child. Length is also considerably decreased, though the weight discrepancies are more drastic. These findings were studied extensively and found to be statistically significant. Using the generalized estimating equation (GEE), Clark was able to analyze the data in a non-linear way. This compensates for correlated data. Clark created density graphs for both male and female children to depict these findings (see figures). When the graph line is fairly close to 1 on the y-axis, or a straight line across the top, this means there is little difference from the standard growth chart (age 2-18). The farther away from 1 on the y-axis, the more significant difference there is compared to standard growth charts (age 0-2).

There is no denying that something is causing these high-altitude children to fall off of the growth charts. The next logical question would be, what are the effects of this smaller growth rate? Initial research shows that children at altitude are catching up on the growth curve by age two. There does not appear to be any long-lasting deficits from the initial smaller growth.

After combing through research articles, a new study from Ladakh, India also displayed a correlation between children living at high altitude and smaller size. Specifically in Colorado, another study shows lower birth weights at high altitude, however, it does not follow the growth patterns of the children over time.

From what this research shows,  a unique growth chart for children living at high altitude would be helpful. A new growth chart would account for the variations in size seen at altitude. This could save thousands of dollars in unnecessary testing looking for underlying disease or endocrine deficiencies as well as the anxiety for parents being told that their child has failure to thrive or is not being fed. Instead of being concerned when a child falls low on the growth chart, one might expect to see smaller children at altitude.

There is still much research to be done in this field. Hopefully, this study will serve as fuel for future studies.

Laura Van Steyn is a 3rd year Physician Assistant student studying at Midwestern University in Glendale, AZ. She graduated from the University of Colorado in Boulder with a degree in integrative physiology. After that, she worked as a CNA at Littleton Adventist Hospital prior to starting PA school. She hopes to work in women’s health or dermatology after graduating. During her six weeks at Ebert Family Clinic, she has joined Dr. Chris for numerous hikes and has truly enjoyed escaping the Arizona summer heat!

References

Yang, W.-C.; Fu, C.-M.; Su, B.-W.; Ouyang, C.-M.; Yang, K.-C. Child Growth Curves in High-Altitude Ladakh: Results from a Cohort Study. Int. J. Environ. Res. Public Health 2020, 17, 3652.

Bailey, B.; Donnelly, M.; Bol, K.; Moore, L.; Julian, C. High Altitude Continues to Reduce Birth Weights in Colorado. Matern Child Health J 2019, 23(11): 1573-1580

Doc Talk with Cardiologist Dr. Pete Lemis

Dr. Peter Lemis is a cardiologist in Summit County, CO. He sat down with us in December to share his experience treating heart patients in the mountains.

Summit County cardiologist Dr. Pete Lemis

I graduated medical school in ‘77, practiced internal medicine in New Rochelle, New York, the first county just north of the Bronx. Then I went to New Hampshire for three years. I was reading the New England Journal and saw an unexpected cardiology opening at Henry Ford Hospital in Detroit. Next I was in Pittsburg for 26 years practicing cardiology. Decided I wanted to retire to Colorado, so I built a vacation home here only to discover I didn’t have to wait to retire to move here, so I came five years ago. 

What is it about high altitude and the heart that makes it healthy for heart patients?

Summit is the fifth highest county in the US with the highest population of those counties. The 21 highest are all in Colorado. Lower air pressure means that although there is 21% oxygen in the atmosphere, there are fewer oxygen molecules. So every breath we take is giving us less oxygen, unless we breathe faster and deeper to make up for it, a natural tendency for people. They don’t even think about it. Some people have hypoxia without shortness of breath. Every once in a while, I’ll see a patient who moved to altitude for work or something, and they’re hypoxic. It is probably genetic that some people have a decreased central respiratory drive. 

These patients with low oxygen often are ordered to have an echocardiogram. When they first come up here, they usually won’t have pulmonary hypertension. For some, the decreased central respiratory drive develops not when they first move here, but years after they move here. They become more and more hypoxic without having the feeling of shortness of breath. They have the same physiological response that people with hypoxia get. Their pulmonary vessels are still being constricted, which is reversible if diagnosed and treated with oxygen supplementation during the first few years of high altitude living. If not treated they are likely to get scarring of their pulmonary vessels. The length of time for this to develop is different for different people, and is unpredictable.

For example, I had somebody just this week who’s been here about 2 years who has a resting oxygen saturation of about 82% at 60 years old. 

We can’t tell who is susceptible to this problem. There are likely some genetic factors involved. Dr. Johnson, who recruited me for my job in Summit County, has been here since 2008. He warned me about the issue of high altitude and hypoxia. Most doctors who are unfamiliar with life at high altitude think you adapt and that’s it. Dr. Johnson said to me, “wait three months and test yourself and your wife with an overnight oximetry to see if there’s hypoxia.” Based on that test I started using nocturnal oxygen and I sleep better when I use it. My wife doesn’t need it. Neither does her mother, who is 90 years old. Neither do my sons.

Awake, we’re able to maintain our oxygen levels, but at night when asleep most people who are here in Summit County have low oxygen. Hence my advice is to get a nocturnal pulse oximetry test. Low oxygen for several hours every night over the years can lead to pulmonary hypertension due to the narrowing of the pulmonary arteries. Then there is the question of what is normal: most high altitude studies were done in La Paz with indigenous, adapted populations as opposed to people living in the mountains of Colorado who have been here years or decades. (See what Dr. Chris has written on her collaboration with physicians and scientists in La Paz, Bolivia.)

We asked Dr. Lemis about arrhythmias at altitude. There are two categories-atrial (from the top chamber) and ventricular (from the bottom chamber).

Studies have shown that cardiac arrhythmias are increased initially, but people become acclimated after about 3 – 5 days and the risk returns to baseline. I don’t think these studies have been conducted over enough time. Hypoxia leads to an increase in arrhythmias. I see a lot of atrial fibrillation  and atrial flutter up here; plus, I send three to four patients a month for an electrical procedure to ablate some of the cardiac conduction pathways to get rid of their arrhythmias. Many patients experience relief from atrial arrhythmias when put on nocturnal oxygen.

JB is a 70 year old who has lived at high altitude for 14 years. He experienced atrial fibrillation several times after returning to Summit County from a trip to sea level. He wore a heart monitor for over a month to see how his heart was beating. He felt the atrial fibrillation was related to dehydration and has prevented further episodes, never needing a pacemaker or other treatment. Jim uses a device that monitors his oxygen and heart rate continually while he sleeps, downloading a written report in the morning.

Why do so many people who live up here have bradycardia?

I think because many are athletes. Athletes often have an efficient heart; I see just as many people who have tachycardia because they have low oxygen. Low oxygen causes higher levels of epinephrine. This stimulates their adrenal gland, which can increase their blood pressure. Many people have high blood pressure at high altitude because they have low oxygen. One of my criteria for testing someone for low oxygen at night is if they have high blood pressure.

Many people have central apnea during sleep at altitude caused by the brain’s blunted response to high CO2 and low O2. Similar to obstructive sleep apnea, this central sleep apnea can increase the risk of heart problems. Many people with obstructive sleep apnea here at high altitude need to have oxygen put into their CPAP machine so they get oxygen, rather than just air with continuous positive airway pressure.

There is less fatal ischemic heart disease up here. People tend to be healthier, more athletic. They’ve moved here for an active lifestyle. There’s less cigarette smoking, more exercise, generally better diet (not always), but people up here still have heart attacks. My impression is more of them survive their heart attacks because of their increased physical activity and healthy lifestyle. They have better collateral flow with more capillaries in the heart. They’re protected to some degree. The corollary to this is the fact that when visitors come here and have heart disease, I don’t think that their cardiologist back at low altitude understands high altitude risks and therefore are unable to provide appropriate medical advice. The same amount of exertion here is much harder on the heart, much more stressful to the heart, than it would be at low altitude. There’s something called a double product when you do an exercise test, related to blood pressure and heart rates. You get the same double product causing the same stress on the heart here as at low altitude, but it takes much less exertion to get to a specific double product. 

People who are accustomed to a certain work load at home come up here and try to do the same amount of exertion. If they have coronary artery disease, suddenly there is a middle aged guy with coronary disease having a cardiac ischemic event, perhaps even sudden cardiac death. 

Another important point is that people with known heart disease who live at low altitude, if they’re unstable at all, they shouldn’t be up here within three to six weeks of a heart attack. They should be able to pass a stress test at low altitude before coming to high altitude to visit.

Valvular heart disease patients who have not been treated with surgery, who don’t already live up here, shouldn’t come up here from lower altitude. People with heart failure can come up here if the failure is compensated.

For people who have trouble acclimating to high altitude in the short term, Diamox is quite useful. Using oxygen at night helps you acclimate as well. Diamox makes your blood a little acidotic which increases your respiratory drive.

Avoid alcohol when you first come to high altitude. Unfortunately people on vacation don’t do that. Alcohol is a respiratory suppressant. At high altitude the hypoxia and cold promotes diuresis, so people tend to get dehydrated. Anti-inflammatory drugs are useful in treating the acute altitude sickness for some people. During the first two or three days, try not to push your physical activity to the limits. Try to get a good amount of sleep.

I would say that I have way fewer heart failure patients [up here]. Because patients who develop advanced heart failure really do not do well here, so they tend to move away to lower altitude before that happens. I have younger patients as compared with my former Pittsburgh practice. I also have way fewer patients with COPD. Anything that causes chronic respiratory difficulties you will find a lot less of that up here. Plus, I’m working in an environment where there are less consultants. 

Back in Pittsburg, two thirds of my practice was taking care of patients in the hospital, so I would deal with patients who would come in with a heart attack, with a heart failure exacerbation, or other acute cardiac problem. Here in Summit County, those severely ill patients get transferred down to Denver, so I provide more in-office preventive or post-illness follow-up than I do care in the hospital. My patients who need advanced procedures (e.g. heart catheters, ablation for arrhythmias), I generally send them down to our sister hospital (St. Anthony in Lakewood). 

The cardiac surgeon who will do the bypass surgery usually knows that the patient returning to the mountains will have to be on oxygen for two weeks after surgery.


Dr. Chris’s HAPE Cheat Sheet

Inflammation and altitude can cause low oxygen. Inflammation is commonly caused by viral infections such as colds or influenza, but can occasionally occur with bacterial infections such as strep throat or pneumonia. Low oxygen, or hypoxia, is the result of fluid collecting in the air sacs of the lungs, called pulmonary edema.

There are three types of high altitude pulmonary edema (HAPE).

  1. Classic HAPE, recognized for over a century. occurs in visitors to altitudes above 8000 ft (2500m) beginning during the first 48 hours after arrival. Symptoms include cough, congestion, trouble breathing, and fatigue, all worse with activity.
  2. Re-entry HAPE occurs in people who are living at altitude, travel to lower altitude, and develop symptoms during the first 48 hours after returning home
  3. High Altitude Resident Pulmonary Edema (HARPE) is a recently recognized illness that occurs mostly in children who have an underlying respiratory illness and live at altitude, with no recent history of travel. They have oxygen levels below 89 and lower but do not appear toxic. They are fatigued but rarely have increased work of breathing.
Parents are often worried their children won’t wear a canula for oxygen, but they don’t typically mind.

Treatment of HAPE is oxygen. There may also be signs of asthma or pneumonia which are treated with bronchodilators and antibiotics. Most people with pneumonia at altitude do NOT have hypoxia. All three types of HAPE can reoccur, but typically not with every arrival at altitude or viral illness. Many of these patients are told they have pneumonia again and again, or severe asthma, and are treated with inhalers and steroids. Usually, this adds nothing to their recovery.

A chest x-ray may show typical infiltrates seen with pulmonary edema, but in mild or early cases, can look normal. There is no blood test for HAPE. Oxygen should be used continuously at a rate that raises the oxygen saturation into the 90’s. Length of treatment may be as short as 2 days or as long as ten days

Most importantly, owning a pulse oximeter and measuring oxygen levels in anyone at altitude with symptoms of cough, congestion, fatigue and trouble breathing with exertion can keep people out of the ER and ICU. HAPE can rapidly progress to respiratory failure and death if not recognized and treated expediently.

The Legacy of the Mountain Guru: Prof. Dr. Gustavo Zubieta-Castillo

We’ve published a series of accounts from Dr. Chris’s recent attendance at the 7th Annual Chronic Hypoxia conference in La Paz, Bolivia , conducted by Dr. Gustavo Zubieta-Castillo. He is one of the world’s leading experts of altitude medicine and Dr. Chris’s collaboration and contact with him has added literally phenomenal insight into our own high altitude research.

Dr. Chris “en Teleférico” with fellow altitude researchers Vanessa Moncada, Diana Alcantara Zapata, Dzhunusova G. S., Oscar Murillo, and Alex Murillo. Photo courtesty of Dr. Zubieta-Castillo.

There is something literarily romantic about the scientists who are compelled to remind you, “I’m not crazy!” Dr. Zubieta-Castillo has held soccer games at 6,542 m (21,463′), proving the remarkable adaptability of the human body. He maintains a high altitude training lab, called the Chacaltaya Pyramid, at 5,250 m (17,224′). In his recent video (below), he illustrates the connection between longevity and elevation, where citizens of the highest cities in South America live to be well over 100.

It’s notable that a city known for its wine at 2,790 m (9,153′), called Chuquisaca, boasts some of the oldest residents. Not surprisingly, our research has led us to some speculation on the relationship between alcohol and the body at altitude. Additionally affirming is Dr. Zubieta-Castillo’s father, nicknamed “El Guru de la Montaña”, who began his legacy of altitude research and medicine by examining the hearts of dogs at altitude (sound familiar? See our article on Dogs at Altitude), as well as Dr. Zubieta-Castillo’s own testament that asthma can be and has been treated by altitude (see Asthma at Altitude).

His latest correspondence with Dr. Chris and their mutual colleagues reads like letters written by history’s greatest scientists, beginning,

Dear Colleague Scientists:

The 7th Chronic Hypoxia Symposium, thanks to your outstanding participation was a great success !! We shared great scientific, friendship and enthusiasm from 16 countries, along with travel and conferences in fascinating environments, all at high altitude.

The letter ends with an invitation to all colleagues to contribute their own research to the first chronic hypoxia-dedicated issue in a top medical journal, so be on the lookout for Dr. Chris’s contribution (which we will be sure to share here).

The video below is a fascinating look into some of Dr. Zubieta-Castillo’s latest research, including his theories and recommendations on conditioning humans in space with hypoxia, a dissertation that was initially dismissed as irrelevant, then subsequently published. Enjoy!

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.

What’s Going On in La Paz?

The 7th Chronic Hypoxia Symposium was held this year in La Paz, Bolivia, in February and March. La Paz, sitting at 11,942 ft. (3640 m), is home to one of the world’s leading researchers of the effects of chronic hypoxia, Dr. Gustavo Zubieta-Calleja, with whom Colorado’s own Dr. Christine Ebert-Santos was able to meet with during her attendance of the symposium. You can refer to her previous article on the gathering of experts from over 16 countries for her own account of Dr. Zubieta-Calleja’s impressive work.

Below is the renowned Dr. Sanjay Gupta’s own account on video of his introduction to the experience of hypoxia and altitude with Dr. Zubieta-Calleja.

Always keep in mind, there are many physiological reactions going on when your body and brain are at altitude, and the higher the altitude, the more extreme the effects. Benefitting from a hypoxic environment isn’t as simple as staying hydrated. When we talk about chronic hypoxia, we are typically referring to a population who have spent many years in a high altitude environment.

robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

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.

Technology in Health Care: Interview with Family Nurse Practitioner Tara Taylor

After over a decade of serving pediatric patients in the high country communities of Colorado as Ebert Children’s Clinic, we opened up our health care practice to serve the needs of the adult population several years ago. As Dr. Chris can attest to, the world of health care has grown and evolved incredibly since she first opened up her practice in Colorado in 2000, and we all continue to learn from the providers we welcome to our team as well as the students we mentor.

Family Nurse Practitioner Tara Taylor.

This past year, we’ve had the pleasure of having Tara Taylor, FNP on our staff. She’s brought a wealth of knowledge and unique experience from having practiced on a medical campus much, much larger than our little mountain clinic, and her insight into everything from patient care to our own high altitude research projects continues to be an invaluable asset to both our practice and our community. She was so gracious one afternoon to have a chat with me between patients:

How did you find yourself in Colorado’s high country health care community?

So, I have actually lived here since 2004, so I’ve lived here 15 years. I came out here for 6 mos to ski, and stayed for 15 years. I found myself loving it, bought my first house and decided to stay out here. I’ve actually commuted down to Denver all this time, because I had originally started in New Jersey in 2002 in Critical Care. So when I moved out here I wanted to be in the mountains, but I also couldn’t do Critical Care up here at that time. So I decided to commute down to Denver for three 12-hours shifts a week, and then live up here four days a week. So I had an apartment in Denver … when I went back to NP school, my goal was to work and live in my own community. I think that’s huge for me … and not only be serving the population of Denver, but to be serving the people of my actual community.

How long had you been practicing in Denver?

Since 2005, because I worked 6 months at Keystone Clinic, so I’ve been in Denver working for 14 years  prior to this in the ICU. And I’ve worked at Children’s hospital in the pediatric ICU, burn ICU’s, bone marrow transplant, open-heart surgery, neuro-trauma, multi-system trauma, all of it.

How is it different working up here, for a small clinic, at that?

This is a huge change … I’m still working down there once a month, so I get to go down and play and enjoy that type of intensity. But at the same time, coming back here, I think that the critical care aspect … it still plays a role here. And in my letter, when they said, “Why do you want to go from [being] an ICU nurse to family practice?” … I said for so long, I’ve seen patients in the ICU [whose] admission or … critical portion of their admission could have been avoided if they had better focus on primary care and had their needs met. If they had been on the right medications, if someone had spent the time — and sometimes it’s because of their own compliance — but with adequate primary care, we’re avoided what I was seeing in the ICU. 

Now, being in primary care, I get the stimulation I need from the independence of it, making these decisions, and I really enjoy finding out what’s going on with the patient, deciding what tests to run, and getting back these results and being able to properly refer them. I enjoy the time that I’m able to have with those patients here at a private practice. So each patient gets the time that they need to be properly cared for. 

And I’m just seeing extremely sick patients. I’m not seeing a lot of sore throats and earaches, unless you’re 2 years old; besides that, the adults have really complex diagnoses that require a lot of thought. And in its own respect, it’s critical to me.

Great segue: what are the greatest challenges you’ve seen practicing up here?

I think some of the biggest challenges that I have seen up here is limitation of services. That’s why this clinic is bringing up Nephrology, … [expanding] mental health services here, and then, to bring in … pain management specialty, and give them a place to practice … It’s really hard for these additional specialties. We have Cardiology up here, we have Pulmonology, but some of the smaller things like Rheumatology for rheumatoid arthritis, for osteoporosis and kidneys … how do you establish your practice up here? So hopefully, as focused as [Ebert Family Clinic] is in the community about being able to provide the care we want for our patients …  we’ll be able to get that door open for those specialties and help them establish their practice up here, which is our goal.

How do you get connected to these services like Genomind?

[This patient] came to me with Genomind. I had not heard of that before. He said, “I got on the right medications because this genetic testing gave [Compass Health] the ability to treat me properly.” [Certain health care providers in Denver] require it, almost, for every patient walking in their door as a prerequisite to help them make medication decisions. 

Genomind is a swab in the cheek. I think it’s huge, because we’re not able to “draw” neurochemicals. We’re not able to draw your blood and say, “oh, look, you’re deficient in serotonin.” Because that’s not an option, what’s the best way for us to figure out what’s the best medication for you? Because medications are very specific to what they’re treating. So the only thing we’ve been able to do for the last decade is to guess; to put you on something, and if it doesn’t work, then we know that’s not the thing. And that’s a terrible process, because it leads patients to trying five medications, over a ten-year period, and finally we get them on the right thing. But how frustrating that is for patients; they lose confidence in their providers, they lose confidence in the system, they feel neglected, they feel frustrated. And to have that stamina to even go through that process … I think we have a lot of patients drop off. [They] end up saying, “Forget it. Medications don’t work for me.” Then [they] become non-functional … their quality of life is hindered by their [unwillingness] to spend ten years trying five medications.

That is not the best process. And I think the people that went ahead and engineered Genomind said, “What else can we do? What if we went back to genetics? What if we went back to genes?” We can swab a 1-day old infant or a 95-year old man, and we are going to get their genetics. And when they did the Human Genome Project, and we got our entire genetic profile as human beings, the science behind Genomind was they were able to take anyone who’s been diagnosed with schizophrenia, people who are known bipolar, generalized anxiety disorder, major depressive disorder, took their DNA … laid them over each other, and said, “What gene is predominant in all these patients?”

So they were actually able to use hundreds of thousands of mental health patients to establish what genes these were that led to the cause of their mental illness. So now we’re able to send off DNA with a swab in the cheek. It’s not a perfect science, but it’s what we have.

Is this better than nothing? There’s so much controversy about this test. How can you think this is controversial when you come from a science background as a provider, as a physician. You’ve got this, or you have nothing to guide you for the mental health of these patients. If we have this over nothing, I will take this.

[Genomind testing] is not only [about] mental health disorders, but also [for] people [suffering from] eating disorders, difficulty losing weight, ADHD, alcohol addiction and propensity for opioid addiction. It would identify what patients we may never want to start on narcotics if at all possible. It tells us, “Don’t start this patient on this particular drug because they’re at risk for gaining weight with this drug, like as an atypical antipsychotic.” It would tell us which medications an alcoholic would respond to best, if they were wanting to quit drinking and needed medication assistance. We have a lot of kids who seem like they’re ADHD, but really they have signs of anxiety and depression as well. And it’s our job to distinguish [whether] it’s the ADHD that’s causing the depression and anxiety, or it’s the depression and anxiety that’s causing the inability to focus? It’s absolutely fascinating! I want the community to know that we’re offering that here at the clinic.

Is Genomind available to children?

We can test anyone of any age. We can swab the cheek of a one-day old. I actually had a mom in here that said she was tested positive for both genes for the lack of ability to metabolize L-methylfolate, which causes bipolar disorder or mood instability. She came in here with her 4-month old son and said, “When can I get him tested to know?”

So I actually asked Genomind, and Genomind said you could test a brand new newborn baby, which at some point may be the standard of practice!

But at this point, it’s hard to want to test that child, because we’re not able to treat that child [without symptoms]. Once that child becomes 6 or 8 years old, and they are having mood instability, they are showing signs of some sort of mental illness, we do realize we are able to identify this in children. We don’t need to wait until people are 18 to say they must have a mental illness. We are identifying that in the behavior of hyperactive two and three year olds, and we’re seeing them grow up to be bipolar adults. So we are seeing early signs and symptoms of mental illness in these children. 

Could we test a 6-year old who is showing signs of something and have them be positive for these genes and be able to supplement them with L-methylfolate or an approved psychiatric medication in the pediatric population based on their genetics? This is absolutely going in that direction. Genomind said they’re 100% approved for adult and pediatric testing.

How do you find balance for yourself and maintain a healthy lifestyle?

Tara with Dr. Chris (center) and Kristen Duffy, A/GNP, at Ebert Family Clinic.

Working at this clinic actually provides me with the exact hours I need to have good work-life balance. That’s extremely important to Dr. Chris Ebert-Santos. When I started working here, she said, “What are your husband’s days off?” And I said, “Sunday-Monday,” she said, “Okay, well you’re not working Sunday-Monday then.” I just honestly couldn’t believe it, that my happiness was that important to her. I work reasonable hours. [Dr. Chris] provides me with the days off that will match my husband’s. I have great quality of life due to my husband. He’s an amazing person, wonderful and spirited, and we get along great. So we have that, and we have our two dogs, and we live a comfortable life up here. We love to do all the great stuff that Summit Countiers do: snowboarding, hiking, biking, camping, just getting outside in general together and playing with our dogs. And that’s what’s most important.

What have been your greatest takeaways from working in Summit County so far?

I think it’s running into that patient at the supermarket who, I know in the back of my head I have their diabetes controlled. To know that I’m specifically helping patients in my community. That I’m doing yoga next to someone [whose] blood pressure is controlled now because of me. I think that’s something really special and it’s not something that I had before when I worked in Denver, and I would come home and I would never see those people again. And then, having the opportunity in this clinic to deal with so many pediatric patients, since this was originally a pediatric clinic [before] expanding to adult services as well, which is amazing. But the amount of pediatrics in this clinic really improves both my exposure to every age group. I love kids. To have patients hug me in this office who have had a very challenging diagnosis … that “thank you” from patients is something I cannot replace.

Tara continues to be a passionate advocate for mental, women’s and sexual health, and a valuable resource as a health care practitioner. Ebert Family Clinic is proud to have her.

robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

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.

Stroke, High Altitude, and EPO

A 2009 study from Switzerland found a 12% decrease in risk of death from stroke at 6430 ft. compared to 850 ft.  This result was more pronounced in men than women.  Since men are more physically active than women in Switzerland, it was thought the exercise at the more hypoxic conditions of higher altitude may benefit them more than for women.  The study also noted that being born at a higher altitude had a protective effect on death from cardiovascular disease1

Strokes occur when blood flow to parts of the brain is cut off causing neurons and other brain cells to die within minutes.  Strokes can either be ischemic or hemorrhagic.  80-87% of strokes are ischemic, which means that blood flow to the brain is cut off from a blood clot or other blockage of a blood vessel going to or in the brain.  Hemorrhagic strokes are caused by bleeding within the brain (intracerebral space) or in the space surrounding the brain filled with cerebrospinal fluid (subarachnoid space).  Risk of stroke is higher in individuals with previous transient ischemic attack (TIA), high blood pressure, previous heart attack, atrial fibrillation, enlarged left atria of the heart, smoking, heavy alcohol use, diabetes, obesity, high cholesterol, and stenosis of the carotid artery2.

Interestingly, on initial exposure to hypoxia at high altitude, blood flow to the brain increases which is split equally between gray and white matter.  After 4 to 5 days, blood flow to the brain decreases but is still 13% greater than at sea level.  The increased blood flow is needed to maintain adequate delivery of oxygen when the oxygen content of the blood is lower during hypoxia, until other acclimation mechanisms take effect3.

As noted in previous blog posts in response to hypoxia, erythropoietin (EPO) is also released, which increases the production of red blood cells to increase the oxygen-carrying capacity of our blood.  Other studies have found that EPO also has a protective effect on neurons.   Cerebrovascular endothelial cells have been found to have receptors for EPO and are thus able respond to EPO.  Other studies have found that EPO is also involved in brain development of a fetus in utero.  Animal studies suggest EPO not only protects neurons from cell death but may enable their regeneration as well.  If this translates into humans, it is an important effect for those at risk for stroke4.

In a small clinical trial, patients with middle cerebral artery stroke received IV EPO daily for 3 days after their stroke.  These patients had better neurological outcomes with increased physical functioning and independence as measured by Barthel index test results.  Following the EPO doses, the size of the cerebral infarct, the damaged area of the brain from blood being cut off during the stroke, was reduced as well4.

Based on this research, Ismailov hypothesized that in the United States, geographic variation in levels of EPO from altitude differences may account for the differences in risk of death from stroke.  He termed it the “stroke belt” in the Southeast, with higher rates of death from stroke compared to the Mountain states.  

The states in the “stroke belt” are Louisiana (LA), Mississippi (MI), South Carolina (SC), Alabama (AL), Georgia (GA), Arkansas (AK), Indiana (IN), North Carolina (NC), Kentucky (KY), Tennessee (TN), and Virginia (VA), and all are at lower altitude.  The mountain states have higher altitude and are North Dakota (ND), Kansas (KS), Nebraska (NE), Arizona (AZ), New Mexico (NM), Wyoming (WY), and Colorado (CO).   

Louisiana and Mississippi’s average altitudes are 100 and 300 ft. compared to Colorado and Wyoming with average altitudes of 6800 and 6700 ft4.  Since there is increased EPO released in individuals living at higher altitudes, perhaps there is more of a neuroprotective effect at higher altitudes, contributing to the observed lower risk of death from stroke seen in the Swiss study.  

Symptoms of Stroke5

Think F.A.S.T

Other signs are sudden

  • Numbness of face, arm, or leg and particularly numbness on one side of body
  • Confusion
  • Difficulty seeing out of one or both eyes
  • Difficulty walking
  • Feeling of dizziness, loss of balance, or coordination
  • Severe headache with no identified cause

For more information: https://familydoctor.org/condition/stroke/

o en Español: https://es.familydoctor.org/condicion/accidente-cerebrovascular/

Author and PA student, Stephanie Schick

Stephanie Schick is a Physician Assistant student at Rocky Vista University in Parker, CO.  She is born and raised in Fort Collins, CO.  She started off her clinical year working in pediatrics with Dr. Chris at Ebert Family Clinic.  The remainder of her clinical year will be spent closer to home in northern Colorado.   In her free time she enjoys spending time with her husband, friends, and family in the beautiful Colorado sunshine.

Spring Recap 2019

We’ve learned a lot in the high country this season! For example, it isn’t too late or too warm for a snowstorm. We’ve conducted several interviews with professional, high-altitude athletes, athletic and tourism organizations in Summit County, physicians, podcasters, interns, and a local brewer. They’ve shed so much light on fitness, health, child growth & development, and acclimation at elevation, it warrants a re-cap:

  1. 8,000 ft. seems to be the pivotal elevation at which the body starts to experience a significant deficit in the oxygen and water it needs to function, affecting everything from sleep to metabolism.
  2. A plant-based lifestyle has benefitted athletes under extreme training and competitive conditions at altitude.
  3. Training at altitude significantly reduces your ability to reach cardiovascular and strength goals, even while preparing your respiratory and circulatory systems for the severe decrease in oxygen. “Live High, Train Low” is an effective strategy more and more athletes are advocating for.
  4. Preparation for backcountry excursions is as much mental as physical.
  5. Foods high in nitrates (like red beets, red bell peppers and arugula) can facilitate acclimation and recovery.
  6. Oily foods may inhibit your body’s ability to cope with a significant increase in altitude.
  7. We metabolize and experience the effects of alcohol differently at altitude.
  8. Current research suggests some people suffering from Parkinsons disease may experience some relieve from symptoms at higher elevation.
  9. Increased muscle mass requires increased oxygen. Being an athlete does not necessarily mean you will have an easier time acclimating.
  10. As always, the best way to facilitate acclimation and deal with symptoms of altitude sickness is to drink plenty of water, allow yourself ample rest, and monitor your blood oxygen saturation levels with a pulse oximeter.

Be sure to subscribe to keep up with what this summer has in store for your elevated experiences at altitude! And if you have any questions or are eager to read more about a particular topic, let us know in a comment!