Category Archives: Medicine

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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. 5: Advances in Frostbite, a Synopsis of Dr. Peter Hackett’s Lecture

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

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

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

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

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

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

Deep Frostbite

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

Stages of Frostbite

What can you do in the field for Frostbite?

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

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

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

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

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

References:

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

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

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

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

Before you go out!

DO:

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

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

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

After coming back inside

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

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

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

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

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

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

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

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

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

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

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

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

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

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

References

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

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

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

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

WMS Blog entry No. 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 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.

COVID-19 Update: Accordion Theory and Preparing for Next Steps

Today, I am going to share news gleaned from meetings and publications that address the importance of preventive care, returning to daycare, pulse oximetry as a screening tool for COVID, and the Accordion Theory.

Every Thursday the Children’s Hospital of Colorado presents a panel of experts with updates and answers to questions.

“Your offices are the safest place in the country,” they proclaimed. With social distancing many parents and patients are delaying routine care which has led to the largest drop in vaccination rates in 50 years. This could result in outbreaks of measles, whooping cough, pneumococcal and other infections. With the loss of revenue, small clinics may go out of business, and large clinics and hospitals are laying off workers by the hundreds. If there is a large outbreak of preventable disease, on top of a resurgence of COVID, there could be a devastating shortage of providers to care for the victims. Now is the time to call your clinic and set up appointments for check ups and vaccines. If you don’t feel safe yet you can do a Telehealth visit initially and schedule the vaccines and hands-on portion of the exam in a month.

Another reason not to delay preventive care is the increase in stress, isolation, and anxiety which can cause serious depression. We had a tragic teen suicide in the county this month. Students from middle school through college should be seen annually for mental and physical health screening as well as vaccines. One mother told me that the depression screening done at our office “saved my daughter’s life.”

More daycares are opening soon. Parents are asking me whether to send their child back. These facilities follow strict public health guidelines to prevent infection. Children are not likely to be affected by COVID. Any child with symptoms should be tested. Enrollment should be diminished due to parents preferring to keep their child at home.  However, if there is a high risk family member, I advise not to return to daycare yet.

School age children should be limited to playing with friends and family members who have been part of their social circle during the last two months. To borrow a slogan from the AIDS campaign, “KNOW YOUR NETWORK”.  This is not the time to expand friendships. There will be no team sports this summer. Children should play outside and not share toys or balls.

An emergency physician in New York, Richard Levitan, published an editorial in the NY Times on April 20 advocating the use of pulse oximeters to screen for COVID. Citing the many patients with low oxygen levels and abnormal x-rays who did not complain of trouble breathing, the delay in obtaining results and inaccuracy of the COVID testing, he sees the simple pulse oximeter as a source of immediate information as to who needs medical attention. I’ve been speaking and writing about this for weeks.

Finally, one of the panelists at Children’s mentioned the accordion phenomenon. As we reduce social distancing restrictions and open commerce and travel, there will inevitably be more cases of COVID. It is likely that restrictions will be imposed again, and this may occur in cycles during the next year(s). We may be able to decrease future shutdowns by wearing masks and gloves when we go out, using hand sanitizer, soap and water, not touching our face, covering our coughs and sneezes, and limiting exposure to large groups of people. I hope all these will be permanent behavior changes except the masks and the large groups (I love the Lake Dillon Amphitheater and the BBQ challenge).

Take care, stay engaged, and have another safe week!

COVID-19: Where Are We At Now?

A panel of experts at the University of Colorado School of Medicine had some good news this morning: we may have passed our peak here in Colorado.

Of the 8,675 cases there are 374 deaths. Less than 2% of those with the illness are under age 18, compared to the population of 22% children. This week there are only 4 children admitted to Children’s hospital with COVID-19, two in the ICU. There is a leveling-off of patients presenting to the hospitals and less ICU admissions.

So social distancing has flattened the curve and no hospitals were overextended or lacked ventilators. The initial R naught (the number of people infected from one individual) of each infected person spreading to 4 is now down to 1.5. A study from Singapore showed that 7% of cases came from presymptomatic persons. The infection can be transmitted 2 to 3 days before symptoms show. Of 121 healthcare workers exposed 35% developed symptoms but only 2.5% tested positive.

Our own experience with testing has been equally frustrating. The virus can be present for weeks but usually rapidly declines after 7 days. The PCR test (polymerase chain reaction test – the standard nasal swab being conducted to test for Corona virus) is said to be 75% accurate in detecting viral RNA. Even patients we’ve tested during the first 4 days of typical symptoms have been negative. Other viruses identified at Children’s Hospital in the last month include rhinovirus, adenovirus, enterovirus and human metapneumovirus, which can all cause fevers and respiratory illnesses.

However, many people we are treating have the unusual symptoms and course that seems unique to COVID. Not all have fever. They experience chills, fatigue, sore throat, then improve. A day later they are having chest tightness, trouble breathing, making it difficult to talk or walk, and upper abdominal pain. They feel worse at night and better in the morning. Symptoms can last for weeks. Lung specialists describe several different effects the virus can have. ARDS (adult respiratory distress syndrome) is a diffuse loss of protective protein that causes the air sacs to collapse. The pulmonary disease in the second week is described as a cytokine storm, where the immune system overreacts and damages the lungs.

Testing is less accurate when the prevalence of a disease is low. In Colorado 1.4% have been affected, in comparison with Wuhan where 5-10% were. Experts and individuals are waiting for antibody testing to see if they are immune and if so for how long. Immunity in similar infections has been shown to last anywhere between 3 weeks and 3 months, as opposed to diseases like measles and chickenpox which confer lifelong immunity.

Pediatricians are seeing few patients in the office these days, which raises the concern for a future epidemic of preventable diseases from a delay in vaccinations. Most clinics, like Ebert Family Clinic, are only seeing healthy patients or those with noninfectious complaints such as eczema and lacerations. Anyone with respiratory symptoms or fever is seen by Telehealth. This is effective because COVID, like most illnesses in the community, is usually mild and self-limited. Antibiotics are rarely indicated. A recent study showed that of several hundred children diagnosed with community-acquired pneumonia, those given antibiotics had the same outcomes at those who were not treated, with 4% of each group needing hospitalization for worsening symptoms.

Telehealth does not allow for auscultation of the heart and lungs (listening with a stethoscope), but the vital signs including oxygen saturation, heart rate and temperature along with the patient’s history usually give the provider enough information to make treatment and testing decisions. A face-to-face video interaction is ideal, protecting the patient and provider from exposure to infection. The expanded use of Telehealth is one of the good outcomes of this pandemic, especially in states like Colorado with far flung rural populations.

 The University of Colorado is doing 3000 telehealth visits daily. Specialists at Children’s are ramping up their services online while accepting the sickest patients in the state for inpatient care. They have the largest number of doctors in Colorado, many of whom are in research and can transfer to frontline and ICU duties. The University does 500 million dollars of sponsored research every year, with over 1000 studies. Many of these are on hold now, but with the capacity to initiate new trials within a week and laboratories adjacent to clinical care sites, CU has been tapped for many COVID-related studies. They are testing several antiviral drugs, including the new product from Gilead laboratories Remdesivir. There are also studies on disease modifying treatments such as steroids to prevent future problems caused by the infection. Other trials focus on sample collecting and processing. Some studies may show results within weeks but others take months or years to determine effect.

The University was one of the first centers to use convalescent plasma to treat COVID. The hope is that antibodies from previously-infected and recovered individuals can be lifesaving for severe cases, although the best timing of such treatment, originally used one hundred years ago in the influenza epidemic, is not yet determined. Plasma donations can be arranged by visiting the UC Health website. Since most people will not need hospitalization, instructions for home care can be found on the CDC website.

Vaccine development will proceed over the next 12 months. Until then, lifting of current social restrictions will depend upon having adequate and accurate testing to find cases early enough to quarantine patients and public health workers to trace contacts. Antibody testing must be done and repeated over months and years to determine susceptibility. Continued use of masks in public and the prohibition of large gatherings may continue for a year.

COVID VS HAPE: Experts Analyze Effect on Lungs

Dr. Chris with Dr. Eric Swenson from the University of Washington

An article published yesterday, April 13, 2020 in the Journal of High Altitude Medicine and Biology clarifies misconceptions in the media comparing high altitude pulmonary edema (HAPE)and COVID lung injury. The six authors include two critical care pulmonologists from the University of Washington: Andrew Luk MD and Eric Swenson MD, as well as Peter Hackett MD of the Hypoxia Institute in Telluride and the University of Colorado Altitude Research Center. Dr. Swenson is the editor of the journal and has given presentations in Summit County on altitude. Both Dr. Hackett and Dr. Swenson personally communicated with Dr. Chris yesterday.

Dr. Chris with Dr. Peter Hackett of the Hypoxia Institute in Telluride, CO

Severe viral pneumonia, as seen in COVID-19, can cause Adult Respiratory Distress Syndrome (ARDS) leading to respiratory failure and the need for ventilator support. As with HAPE, this is a form of non-cardiogenic pulmonary edema, where the air sacs in the lung fill with fluid due to conditions not related to heart failure, the most common cause of pulmonary edema. Other causes include bacterial pneumonia, near-drowning, nervous system conditions, re-expansion, and negative pressure edema. Radiographic findings are similar in all these cases with diffuse bilateral densities in the lungs. All these patients have severe hypoxia.

At altitude, hypoxia can lead to uneven pulmonary vascular constriction, (hypoxic pulmonary vasoconstriction or HPV). In the areas with the highest pressure, fluid leaks from capillaries into the alveoli. With COVID, alveolar inflammation reduces the protein surfactant that maintains expansion of the alveoli. The alveolar collapse causes hypoxemia, low blood oxygen. Severe viral and bacterial infections also cause inflammation in other organs, such as the liver, kidneys, and brain, which is not seen with HAPE.

Medications used to treat HAPE are not likely to be useful in treating COVID pneumonia and may have harmful effects such as increasing perfusion to damaged areas of the lung that are not oxygenated.

Both these conditions likely have large numbers of patients with mild symptoms who recover without seeing a medical provider. However, both HAPE and COVID can cause a sudden, rapid deterioration with severe hypoxia and death.

ACCESS TO A PULSE OXIMETER TO TRACK OXYGEN SATURATION IS VITAL.

Oxygen levels below 90% merit medical attention. Pulse oximeters can be purchased online, at drug stores, or at Ebert Family Clinic.

COVID Vs. HAPE: Frontline Theories on Treatment

A good friend in Hawaii recently sent me a YouTube video referencing Dr. Cameron Kyle-Sidell, a critical care and emergency room physician at Maimonides Medical Center in NYC.  Dr. Kyle-Sidell was discussing his findings while working with COVID-19 patients in NYC and compared those findings to altitude sickness. I did a search and found he had posted several videos on social media comparing Acute Respiratory Distress Syndrome (ARDS) in COVID-19 patients to altitude sickness and reconsidering how these patients are treated. Altitude sickness is something I see and treat frequently here in Summit County. Based on the similarities between the two conditions, the same treatment for altitude sickness and high altitude pulmonary edema (HAPE)[1] may be beneficial to COVID-19 patients.

In an interview with Dr. John Whyte, Dr. Kyle-Sidell described the acute ARDS he is seeing in COVID-19 patients as atypical and not responsive to standard treatment, specifically in regards to ventilator use and settings. He describes some of his patients as alert, talking in full sentences, and not complaining of shortness of breath but have oxygen saturation levels in the 70s (John Whyte & Cameron Kyle-Sidell, 2020). Normally, that is not the case when a person has an O2 saturation[2] in the 70s and is in respiratory distress. However, this is not abnormal in patients with altitude sickness and HAPE. There are certain protocols in hospitals regarding when to intubate a person and to put them on a ventilator. According to Dr. Kyle-Sidell, these protocols apparently aren’t always helpful for COVID-19 patients with ARDS, and can at times be harmful.

The similarities between findings with COVID-19 and HAPE are remarkable. These similarities include: hypoxia (low oxygen levels), low CO2 (carbon dioxide) levels, tachypnea (rapid respiratory rate), patchy infiltrates seen on chest x-ray, bilateral ground glass appearing opacities on chest CT, fibrinogen levels/fibrin formation, aveolar compromise[3], decreased Pao2:FiO2 ratios[4], and ARDS in severe disease (Solaimanzadeh, 2020). Noting these similarities may be helpful when approaching treatments for COVID-19.  Acetazolamide (Diamox), Nifedipine (Procardia) and Phosphodiesterase inhibitors (Viagra, Cialis etc.) have been used in treating HAPE and could possibly be beneficial in treating COVID-19. For example, Acetazolamide potently decreases the constriction of small vessels in the lungs that contribute to fluid build up (edema) seen in both HAPE and COVID-19 patients (Solaimanzadeh, 2020).

In our house call practice, we treat quite a bit of altitude sickness due to our elevation here in Summit County. During the ski season, we may see 3-4 patients per month that develop HAPE. The majority of the time, these patients can be safely treated and monitored in their residence or hotel room. Treatment for both altitude sickness and HAPE consists of oxygen, usually 2-5 L/min via nasal cannula continuously while sleeping or resting. We also treat our patients with an injection of a steroid, Dexamethasone. We closely monitor them and may repeat the dose of Dexamethasone or prescribe an oral steroid. These patients usually see some improvement by the next day and significant improvement when they descend in altitude. I have read recommendations for and against steroid use with COVID-19.  More studies need to be done, which I will be following closely as future recommendations may change how I treat HAPE when there is also a suspicion of COVID-19.

The key to treatment is oxygen! We’ve seen patients with O2 saturation levels in the 40s and 50s and lungs that sound like a “washing machine”, as Dr. Gray, has described it (in a previous Doc Talk article). If we can get their oxygen saturation up into the mid 80s or 90s on 5L/min (of O2) or less via nasal cannula, typically, they can avoid an ambulance ride and emergency room visit. As Dr. Kyle-Sidell notes, many of the COVID-19 patients he sees are talking coherently and not in severe respiratory distress. A friend who is an EMT in New York described a man he recently transported to the hospital, in his 50’s, with presumed COVID-19. He had no respiratory distress, walking and talking coherently, no chronic medical problems but his oxygen saturation was in the 60s. He said they took him to the emergency room and he was intubated and placed on a ventilator. Apparently, this is a common occurrence from what he has seen. I am still amazed when a patient calls, gives me their address and directions to where they are staying and when I arrive, their oxygen levels are in the 40s. It is a very rare occurrence that I need to send a patient to the hospital, which they always appreciate. We monitor our patients very closely until their departure and have them call anytime, day or night, with any changes in condition.

Dr. David Gray, who started our business, has been treating these patients for over 18 years. He states that in a few of the HAPE patients that he has treated, including his own 13-year-old son, he has seen O2 saturations in the 30’s & 40’s. In these few patients, he was only able to get their O2 saturation up to high 60’s, low 70’s, on 5 liters. They were so much improved, clinically, that he accepted those levels. A large dose of Dexamethasone & 12 hours of rest, on nasal oxygen, resulted in marked improvement by the next day, every single time. His rule, as in patients with DKA, is “if the pathology didn’t happen rapidly, you don’t necessarily have to reverse it rapidly.”

Dr. Kyle-Sidell suggests not putting COVID-19 patients on ventilators based solely on numbers (John Whyte & Cameron Kyle-Sidell, 2020). Treating these patients with prone positioning, oxygen via nasal cannula, high flow on a non-rebreather mask or CPAP[5] along with careful monitoring and a little patience may be preferable to a ventilator (John Whyte et al, 2020). If a ventilator is needed, using less pressure to reduce lung damage and higher oxygen levels may prove to increase the likelihood of a better outcome (John Whyte et al, 2020). There is so much to learn about COVID-19 and how to treat it. Treating it as you would with HAPE is certainly something to consider. I appreciate providers who are sharing their personal experiences in treating these patients. As healthcare providers gain more experience treating this virus and share their experiences, protocols will change and I suspect ventilator use as well as the death rate will decrease.

[1] A complication of altitude sickness in where the lungs fill with fluid and small amounts of blood

[2] Blood oxygen level

[3] Damage to the tiny sacks in the lungs where gas exchange occurs

[4] partial pressure of arterial oxygen: percentage of inspired oxygen ratio used to determine ARDS and lung damage

[5] Continuous positive airway pressure

Danielle Shook MSN, NP-C is a board-certified Family Nurse Practitioner. She has been in nursing for over 27 years. She earned her Master’s Degree at University of Colorado, Colorado Springs through Beth El School of Nursing. Her nursing experience includes 10 years in Obstetrics and 7 years in Hospice home care. She has over 9 years experience as an NP which includes Family Practice at the Air Force Academy, Urgent Care, Acute and after hours care with the Army Premier Clinic as well as house calls.

References

John Whyte, Cameron Kyle-Sidell. Do COVID-19 Vent Protocols Need a Second Look? – Medscape – Apr 06, 2020.

Solaimanzadeh I (March 20, 2020) Acetazolamide, Nifedipine and Phosphodiesterase Inhibitors: Rationale for Their Utilization as Adjunctive Countermeasures in the Treatment of Coronavirus Disease 2019 (COVID-19). Cureus 12(3): e7343. doi:10.7759/cureus.7343


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.