What happens to your body’s physiology when you move between low and high elevations?
Dr. Chris has the medical community talking about HAPE!!!
“Health providers should advise patients who live at or travel to high altitude to have a pulse oximeter and check their oxygen levels if they are unwell,” the study’s author, Dr. Christine Ebert-Santos at the Ebert Family Clinic in Frisco, Colorado, told Reuters Health…
Click the link to read more:
High-Altitude Lung Edema Can Mimic Pneumonia in Kids, Even Without Travel by Rob Goodier
http://www.medscape.com/viewarticle/867210
With all the news about the 400% price increase in epi-pens, we don’t want to waste them. So what if we are backpacking at high altitude and eat some peanut butter by mistake in our energy bar? Then our face swells up like a chipmunk and we start to wheeze? We whip out the epi-pen from the external pocket of our pack only to find out it is frozen!! Oh, oh. What do we do now? Good news! at the 7th World Congress of Mountain and Wilderness Medicine in Telluride we heard the exact scenario described. It happened to a scientist, who then did a study to measure the effectiveness of the epi-pen after freezing and thawing. It still worked! So don’t throw out your frozen epinephrine. thaw and use.
Another tip: if you can’t afford the new price of the epi-pen, maybe your physician could prescribe injectable epi with a syringe to have on hand.
In beginning my Physician Assistant rotation at Ebert Family Clinic I was introduced to the exciting research of Christine Ebert-Santos, MD. The research surrounded a condition known as High Altitude Pulmonary Edema (HAPE). In growing up at altitude myself, at 6,926 feet in Jamestown Colorado, I have had some exposure to the effects of high altitude. Acute Mountain Sickness (AMS) is a condition that I am more familiar with and in reading Dr. Ebert-Santos’ research it became clear to me that HAPE is a more severe complication to those ascending to or living at altitude, especially if they develop an initial respiratory illness. In her paper Dr. Ebert-Santos describes several pediatric case studies that demonstrate the characteristics of this treatable condition. These patients presented with tachycardia (fast heart rate), tachypnea (fast breathing), decreased oxygen saturation, and rales (abnormal breath sound). Many of the children described were seen directly after an initiating illness such as the Flu. While seen in the clinic, or during admission to the hospital, these patients were treated with oxygen. The fact that HAPE can be treated with something as simple as oxygen is noteworthy.
Through her research Dr. Ebert-Santos has demonstrated that HAPE should be considered in all pediatric patients presenting to clinics or emergency rooms at altitude with hypoxia (decreased oxygen saturation) and a recent viral illness. Through placing HAPE in their differential diagnosis, clinicians can avoid giving excessive inhaled steroid treatments and unneeded antibiotics. Awareness of the prevalence of this disease in both travelers and residents alike ensures a decrease in the incidence of unfavorable outcomes from this potentially fatal condition.
Submitted by Kelly Kyte, Physicians Assistant Student from Red Rocks Community College Fall Rotation 2016
With apologies to John Denver, here in the mountains, it’s not just the sunshine on your shoulders that makes you smile. Scientists have been studying the effects of high altitude and mild hypoxemia on dopamine, one of the chemicals in the brain. Dopamine causes feelings of pleasure and happiness. At higher altitudes where oxygen levels in people are lower, dopamine levels are increased.
Here’s a little bit more on how that works: Oxygen makes up 21% of the atmosphere. At sea level, 100% of that oxygen is available to breathe. With a rise in altitude, barometric pressure decreases causing the air molecules to become more spread out. This means that at 10,000 feet above sea level, only 70% of atmospheric oxygen is available to breathe. This results in a state of mild hypoxemia, or lower levels of oxygen in the blood, which in turn causes increased levels of dopamine.
You can read more about dopamine and altitude here:
Toler, A. (2014). “Your brain on altitude.” Catalyst Magazine. Retrieved from http://www.catalystmagazine.net/your-brain-on-altitude-2/
Here’s more about the effects of altitude on oxygenation:
Peacock, A.J. (1998). Oxygen at high altitude. British Medical Journal, 317 (7165). p1063-1066.
Here a calculator to figure out oxygen and barometric pressure at different altitudes:
http://www.altitude.org/air_pressure.php
Submitted by Rebecca Somershoe PNP Student from Vanderbilt University rotating Summer 2016
I just came across this study in the literature from a couple years ago
Optimizing Altitude for Live High-Train
Low (LHTL) Training
Chapman et al (2013) hypothesized that athletes living at
higher altitudes would experience greater improvements in sea
level performance, secondary to greater hematological acclimatization,
compared to athletes living at lower altitudes. After
4 weeks of group sea level training and testing, 48 collegiate
distance runners (32 men, 16 women) were randomly assigned
to one of four living altitudes (1780m, 2085m, 2454m, or
2800 m). All athletes trained together daily at a common altitude
from 1250m to 3000m following a modified LHTL
model. Subjects completed hematological, metabolic and
performance measures at sea level before and after altitude
training. Upon return from altitude, 3000m time-trial performance
was only significantly improved in groups living at the
middle two altitudes. EPO remained elevated after 72 h except
in the 1780m group. Erythrocyte volume was significantly
higher in all groups but not different between groups. These
data suggest that a 4 week LHTL altitude camp at 2000m to
2500m is optimal for sea level performance.
HIGH ALTITUDE MEDICINE & BIOLOGY
Volume 15, Number 1, 2014
ª Mary Ann Liebert, Inc.
DOI: 10.1089/ham.2014.1513
4
We frequently measure oxygen levels on people of all ages here in our mountain clinics. We order nighttime oximetry and sleep studies and analyze hundreds of data points reflecting heart rate and oxygen levels over time. When we see someone with a low oxygen in clinic, there may be no way of knowing if they have been hypoxic for hours, days, weeks unless they have an illness with an abrupt onset, like influenza or pneumonia or they just returned from sea level. Babies during the first weeks may have low oxygen with no symptoms, since they are accustomed to this in the womb where oxygen saturations run 40-60 %.
A recent article in the Journal of the American Medical Association studied extremely premature babies at 18 months for adverse outcomes including vision, hearing, cognition, motor, and language. They correlated the degree of disability with the length of time the child was hypoxic during the first few months. One minute of hypoxia seemed to be the cut-off. Now this doesn’t tell us how low or how many but it may be a helpful guide when watching someone’s oxygen or analyzing a sleep study. Shorter episodes may be insignificant long term.
This is a complex article and the children with the poorer outcomes had more episodes of hypoxia at older ages- 9-10 weeks after birth. This could mean that the insult to the brain was contributing to the hypoxic episodes as well as the deficits.
A study of 2789 men and 1886 women aged 14 to 85 years old showed a reduced risk of altitude sickness above age 46. The study controlled for age, sex, rate of ascent, final altitude, training status and chemoreceptor responsiveness. Thirty subjects were also evaluated again after a ten year interval.Aging men showed a decreased response to hypoxia with less pronounced desaturation. Men and women had a decreased cardiac response to low oxygen as they aged.
In this article there were numerous citations of other studies including one that showed an increased risk of severe high altitude illness in endurance athletes.
Jean-Paul Richalet,1,2 and Franc¸ ois J. Lhuissier1,2 High Altitude Medicine and biology June 2015
I have read many scientific studies on athletic performance at altitude. Active high altitude residents are always looking for ways to improve. As we age we experience a loss of speed and endurance, even with regular training. Some of this is inevitable, but how can we know if there is something else affecting our fitness?
I started sleeping on oxygen 9 months ago because of high blood pressure, which was instantly cured. Now I find that my strength and endurance have improved during the last few months. For example, I was rowing 13400 meters per hour with several brief pauses last fall, and now I am at an all-time high of 14100 m per hour with one pause. My running feels better, I’m back up to 6 miles from 4.
There are other factors that could influence this. In 2012-2013 I was on 17 pills including prednisone and had four surgeries for tongue cancer and myasthenia gravis. I was able to continue working out daily although part of that was less intense, such as yoga. I also had rotator cuff surgery. So my current fitness improvement could just be a rebound from overcoming those health conditions.
The only way to know for sure is to do a randomized controlled double blind study of athletes performance on and off nightly oxygen, or study the same athlete with and without oxygen. This is not an immediate effect, so months or years of observation and measurements would be needed.
In the meantime, if you live above 2500 meters/9000 feet and are losing stamina or strength consider having a night time pulse oximetry test to check for hypoxia during sleep.
Most people will agree they do not sleep as well at high altitude, especially over 9000 ft/2500 m. In sleep, the drive to breathe is blunted, which may lower the oxygen and raise carbon dioxide in the blood. This causes high blood pressure in some adults and children but what else does it cause? Pediatric pulmonologist and sleep specialist Ann Halbower wonders if it effects growth and development in children. Family practice physician Lisa Zwerdlinger has many years of experience treating patients in Leadville and sometimes has babies that need oxygen for a year to gain weight.
A study published in the Archives of Diseases of Children in February this year analyzed previously published studies of oxygen levels in awake children at altitudes between sea level and 4000 meters, including Summit County. We are in the early phase of formulating a study on night time oxygen levels at various ages. since it takes years for research to be completed we recommend anyone with health issues that may be related to altitude to have a sleep study. this is very simple: a finger clip connected to a wrist band where data is collected.
Several parents returned to the clinic this week with their children on oxygen after respiratory illness. Our protocol has been to discontinue the oxygen when their saturation is above 89 in clinic. Now that many parents have a home pulse oximeter, children are using oxygen for longer periods. Measurements at home may be fine during the day, and the child attends school, then decreases at night so parents continue oxygen. since most oxygen equipment is rented by the month, this is not more expensive. I think it helps the lungs to heal, possibly reducing future problems such as pulmonary hypertension.
New information comes from one of the students rotating here at Ebert Family Clinic: Justin Lockwood, a pediatric resident. He reports that even in Denver some children require oxygen during respiratory illnesses that do not get a diagnoses of asthma or pneumonia.
