A TRUE STORY OF SURVIVAL IN THE HEART OF THE ROCKIES
This book by long time Colorado high country resident, writer and hut master Devon O’Neil is essential reading (or listening) for everyone who loves nature, mountains, rivers, adventure, or snow. Skillfully written to weave in stories of tragedies and near-misses, he includes details about avalanches, frostbite, hypothermia, river raft catastrophes, mountain bike crashes and moose attacks- something for everyone!
We are including a review of this book on highaltitudehealth.com because the true story it describes is a scenario not unlike many others that have occurred (and always has the potential to play out) at so many backcountry high altitude excursions. At a recent author event with Devon at Next Page Books in Frisco, CO, the author even noted that part of the appeal and thrill of these experiences are the risks inherent in the activity, which includes, not least of all, changeability of weather and conditions in high altitude environments.
Headlamps of hut trip members searching for late arrivals
The main story involves a group of families from Salida, Colorado who embark on a trip to Uncle Bud’s Hut at 11,000 ft. Fathers and their teens come from a variety of backgrounds but all with some expertise in medicine, rescue, and extreme sports. When a snowstorm comes in and two of them are separated and missing the rescue team is also broad, experienced, and personally committed to finding their friends. All the family members affected by this event are skillfully and sympathetically portrayed. Colorado readers will relate to the locations, relationships and situations. O’Neil includes a thoughtful discussion of the risks we take in our sports and recreation and how it can affect us and our families in the years to come.
This narrative contains crucial information for staying safe as described in our blog posts about climbing fourteeners and hut trips, such as wearing layers of wear clothing that wick moisture, carrying adequate nutrition and water, using communication devices with backup power sources, strategizing fire starting materials, and avoiding dangerous wildlife.
In spite of the dangerous events described in this particular account, Devon also noted personally that his aim was not to diminish the importance of embracing the adventure of being in the outdoors in the face of risk. It is in the risks, after all, that we find so much of the thrill of every outdoor adventure.
I expect someday this book will be a movie, bringing Into Thin Air (the book by Jon Krakauer that was a hit movie) to our backyards..
My love for hiking developed during my childhood explorations of the breathtaking landscapes of the Sierra Nevada. As I ventured into the rugged mountains and hiked along scenic trails, I couldn’t help but feel a deep connection with nature. However, my passion for hiking was not without its moments of caution. On several occasions, I witnessed the awe-inspiring yet intimidating power of lightning storms dancing across the vast mountain skies. These encounters instilled in me a profound curiosity about the risks associated with lightning strikes in high-altitude regions.
When I moved to Colorado for PA school, my awareness of the dangers posed by lightning strikes grew even stronger. The dramatic topography and frequent thunderstorms in Colorado amplify the risk for individuals exploring high-altitude areas. It was during my last clinical rotation at a burn unit that I had the opportunity to care for several patients who had been struck by lightning. Witnessing the effects firsthand fueled my determination to educate the public about the actionable steps they can take to stay safe during lightning storms.
Lightning strikes
Lightning possesses an immense amount of energy, with a voltage of over 10 million volts (in comparison, most car batteries measure 12.6 V).1 Additionally, a lightning bolt reaches incredibly high temperatures, reportedly up to 30,000 Kelvin (53540.33 F).1 Lightning injuries occur in different ways, including as direct strikes, side splash, contact injuries, or ground current.
Direct strikes are uncommon, accounting for only 5% of cases, and happen when a person is directly struck by lightning.2
Contact injuries occur when a person touches an object that is struck by lightning. 2
Side splash injuries occur when the current jumps or “splashes” from a nearby object and then follows the path of least resistance to reach the individual. These injuries make up about 1/3 of all lightning related injuries. 2
Ground current is the most prevalent cause of injury, accounting for half of all cases, and occurs when lightning strikes an object or the ground near a person and subsequently travels through the ground to reach the individual. 2
In Colorado, an average of 500,000 lightning flashes hit the ground each year. Based on data since 1980, lightning causes 2 fatalities and 12 injuries per year throughout the state.3According to data since 1980, lightning causes an average of 2 fatalities and 12 injuries annually throughout the state.3 Colorado ranked third in the United States for the number of lightning fatalities between 2005 and 2014, as depicted in Figure 1.
Fig. 1. Lightning fatalities by state. 3
The high number of injuries attributed to lightning in Colorado can be influenced by several factors. One of these factors is the easy access to high elevation terrain, such as 14ers (mountains with a peak elevation of at least 14,000 feet). This accessibility allows inexperienced outdoor enthusiasts to venture into potentially dangerous situations due to their lack of knowledge and preparation.
For instance, individuals who are not familiar with summer weather patterns may embark on a hike above the tree line late in the day, underestimating the risk of a storm forming. This lack of understanding puts them in an exposed and perilous position should adverse weather conditions arise.
Even with thorough preparation and extensive knowledge of weather patterns, it is still possible to find oneself in a situation where you have to weather a storm. Given that a significant proportion of Colorado’s hiking trails are located above the tree line, where appropriate shelter is sparse, hikers are more susceptible to lightning strikes in these exposed areas.
Pathophysiology of Lightning Strike Injuries
The overall ratio of lightning injuries to deaths is 10:1 and there is a 90% chance of sequelae in survivors.4 The primary mechanism of injury in lightning strikes is the passage of electrical current through the body. The high voltage and current can cause tissue damage through several mechanisms, including thermal injury, electrical burns, and mechanical disruption of tissues. The severity of the injury depends on factors such as the voltage and current of the lightning bolt, the duration of contact, and the pathway the current takes through the body.
Lightning strikes can cause various types of injuries, with cardiac and respiratory arrest being the most common fatal complications.5 The path of least resistance determines the flow of electricity through different organs in the body, with nerves being the most conductive, followed by blood, muscles, skin, fat, and bone. 5 When lightning strikes, the electrical surge can induce cardiac arrest and cessation of breathing by affecting the medullary respiratory center. As a result, most patients initially present with asystole and may progress to different types of arrhythmias, commonly ventricular fibrillation. 5
Interestingly, there have been case reports documenting successful resuscitation of lightning strike victims who were initially apneic and pulseless for as long as 15 to 30 minutes. 5This has led to the recommendation that in the immediate aftermath of a lightning strike, individuals who appear to be dead should be prioritized for treatment.
Superficial skin burns are experienced by around 90% of lightning strike victims, but deep burns are less common, occurring in less than 5% of cases. A characteristic skin manifestation of a lightning strike is the Lichtenberg figure, which is considered pathognomonic. Neurological symptoms can also occur, including keraunoparalysis, which is a transient paralysis affecting the lower limbs more than the upper limbs. This paralysis is often accompanied by sensory loss, paleness, vasoconstriction, and hypertension, and is thought to result from overstimulation of the autonomic nervous system, leading to vascular spasm. In most cases, this paralysis resolves within several hours, but in some instances, it may last up to 24 hours or cause permanent neurological damage. 5
Additionally, it is common for lightning strike victims to have a perforated tympanic membrane (eardrum) or develop cataracts immediately following the incident. These injuries to the ear and eyes are associated with the intense energy of the lightning discharge.6
What can hikers do to stay safe?
Preparation
Monitor weather forecasts: Stay updated on weather conditions before engaging in outdoor activities, especially in areas prone to thunderstorms. Pay attention to thunderstorm warnings or watches issued by local authorities. Having a mobile or handheld NOAA Weather Radio All-Hazards (NWR) can also be helpful as it can transmit life-saving weather information at a moment’s notice.
In Colorado most thunderstorms develop after 11 am, so it is best to plan your trip so that you are descending by late morning.7Fig. 2 shows number of lightning fatalities by time of day in Colorado between 1980 and 2020. The vast majority take place after the 11 am threshold.
Fig. 2 Lightning fatalities in Colorado by time of day3
What to Do If Caught in a Storm
If you can hear thunder, you are close enough to be struck by lightning. Lightning can strike up to 25 miles away from the storm. 7 Once you hear thunder, if possible quickly move to a sturdy shelter (substantial building with electricity or plumbing or an enclosed, metal-topped vehicle with windows up). Avoid small shelters, such as picnic pavilions, tents, or sheds. Stay sheltered until at least 30 minutes after you hear the last clap of thunder.
Fig 3. Areas to avoid when sheltering from lightning.
If you are outdoors and cannot reach a suitable shelter, avoid open areas, hilltops, and high places that are more exposed to lightning strikes. Seek lower ground and stay away from tall objects, such as trees, poles, or metal structures. Bodies of water, including lakes, rivers, pools, and even wet ground, are conductive and increase the risk of a lightning strike. Move away from these areas during thunderstorms. Separate group members by at least 20 ft as lightning can jump up to 15 feet between objects.
If a strike is eminent (static electricity causes hair or skin to stand on end, a smell of ozone is detected, a crackling sound is heard nearby), the current recommendation is to assume “lightning position”, pictured in Fig. 4.
Fig. 4. Lightning position8
To potentially reduce the risk of ground current injury from an imminent lightning strike, another strategy is to insulate oneself from the ground. This can be done by sitting on a pack or a rolled foam sleeping pad. However, it’s important to note that this and the lightning position should be considered a strategy of last resort and not relied upon as the primary means of prevention. Maintaining this position for an extended period can be challenging, and it’s crucial to prioritize seeking proper shelter and following established lightning safety guidelines to minimize the overall risk of injury. 5
Case Study
25 YO F presents to the Burn Unit as a transfer from Cheyenne Regional Medical Center s/p lighting strike. Patient (pt) was caught in a thunderstorm on a hike and sheltered under a tall tree. Suddenly, she felt like she was being lifted up into the air and then dropped. Pt had a brief (<5 sec) loss of consciousness (LOC). When she woke up, she was completely numb and couldn’t move any of her extremities. Witness (friend) states the lightning splashed from the tree to the pt. Pt denies hitting her head with the fall. She denies taking blood thinners. She has no past medical history (PMHx) or past surgical history (PSHx).
Physical exam
Neuro: AOX4, No CN deficit on exam, LE paralysis resolved, LE paresthesia improving but still present
HEENT: L ruptured tympanic membrane, hearing loss on L side
CBC, CMP, troponin were all WNL. Serum hCG negative. CK mildly elevated (222)
EKG showed NSR.
CXR, CT brain, and c-spine neg for acute injury
She was admitted to the UC Health burn center for observation with tele. Her lab work and vitals remained stable throughout her hospitalization. She was evaluated by the trauma team with a negative trauma work up. The day of discharge, she was tolerating a regular diet, ambulating and sating well on room air. She was deemed appropriate for discharge home without patient audiology and ophthalmology follow up.
References
1. US Department of Commerce N. Understanding lightning science. National Weather Service. April 16, 2018. Accessed July 8, 2023. https://www.weather.gov/safety/lightning-science-overview.
2. Cooper MA, Holle RL. Mechanisms of lightning injury should affect lightning safety messages. 21st International Lightning Detection Conference. April 19-20, 2010; Orlando, FL.
3. US Department of Commerce N. Colorado Lightning statistics as compared to other states. National Weather Service. March 4, 2020. Accessed July 7, 2023.https://www.weather.gov/pub/Colorado_ltg_ranking.
4. US Department of Commerce N. How dangerous is lightning? National Weather Service. March 12, 2019. Accessed July 8, 2023. https://www.weather.gov/safety/lightning-odds.
5. Chris Davis, MD; Anna Engeln, MD; Eric L. Johnson, MD; Scott E. McIntosh, MD, MPH; Ken Zafren, MD; Arthur A. Islas, MD, MPH; Christopher McStay, MD; William R. Smith, MD; Tracy Cushing, MD, MPH. Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries: 2014 Update. WILDERNESS & ENVIRONMENTAL MEDICINE. 2014; 25, S86–S95
6. Flaherty G, Daly J. When lightning strikes: reducing the risk of injury to high-altitude trekkers during thunderstorms. Academic.oup.com. Accessed July 8, 2023. https://academic.oup.com/jtm/article/23/1/tav007/2635599.
7. NWS Colorado Offices – Boulder G. Colorado Lightning Awareness Week june 19-25, 2022. ArcGIS StoryMaps. June 25, 2022. Accessed July 8, 2023. https://storymaps.arcgis.com/stories/11d021f1b800429a869ead2dc32c0f96.
8. McKay B and K. How to survive A lightning strike: An illustrated guide. The Art of Manliness. April 25, 2022. Accessed July 8, 2023. https://www.artofmanliness.com/skills/outdoor-survival/how-to-survive-a-lightning-strike-an-illustrated-guide/.
Sophia Ruef is a Physician Assistant student at Red Rocks Community College in Arvada, CO. She grew up on the central coast of California and earned her Bachelor of Science degree inBiology with a concentration in anatomy and physiology from Cal Poly San Luis Obispo. She worked as an EMT and a tech in the Bay Area after her undergraduate education. In her free time, she enjoys hiking, backpacking, canyoneering, and spending time with family and friends.
Ultrasound itself is not an unfamiliar technology to most, having been used in obstetrics and gynecology (OB/GYN) for many years. Newer research is now showing that ultrasound imaging may have good applicability in both high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). Pulmonary edema (or fluid in the lungs) is identified as “B-lines” or “comet tails” and is easily distinguishable on ultrasound (Gargani, 2019).
Gargani, 2019
Using ultrasound to measure the diameter of the optic nerve can also assist with a diagnosis of HACE, as an increased diameter indicates increased intercranial pressure from HACE (Shookahi et al., 2020). The advantages of ultrasound over traditional imaging include being highly portable and usable in austere environments (such as back country), no radiation like many other imaging techniques, accurate for diagnosing pulmonary edema and other conditions, and takes little time for providers to master. Ultrasound also has a significant cost savings as the machine itself is relatively inexpensive, does not require special construction like adding lead to an Xray room, and is applicable in many other diagnoses (including kidney disorders, gallbladder disease, pneumonia, trauma, muscular disorders, and gynecological complaints). Ultrasound also has the capability to differentiate types of pulmonary edema, as well as other lung disorders, and generally much faster than a traditional Xray as there is no radiographic lag between clinical onset and ultrasound changes.
Pulmonary Edema on Xray, Mayo Clinic, 2024
Pulmonary Edema on Xray Mayo Clinic, 2024
In HAPE, an increase in the number of B-lines indicates an accumulation of fluid in the lungs. Healthy individuals acclimating to the altitude have been shown to have a physiologic increase in B-lines during the first 4 days of high-altitude exposure as well as pregnant individuals having an increase in their baseline b-line count. Keeping these differences in mind, an increase of B-lines of more than 3 in a lung field, in more than 2 lung fields indicates an increase in extravascular lung water (EVLW) and could support a diagnosis of HAPE. Correlating this with clinical signs and symptoms of altitude sickness (HA, dizziness, fatigue, shortness of breath, nausea/vomiting), as well as HAPE (hypoxia, cough, exercise intolerance) can support a more rapid diagnosis of HAPE as well as assist with deciding need for oxygen and/or altitude descent (Yang et al., 2018; Heldeweg et al., 2022). The provider can also use the ultrasound to monitor resolution of the pulmonary edema to help support decisions to discontinue oxygen or to encourage altitude descent. Those with comorbidities such as heart failure can also be monitored for early signs that their treatment plan is not adequately addressing their EVLW and can receive correction prior to needing hospitalization (Chiu et al., 2022).
Pulmonary Edema on Xray Mayo Clinic, 2024
HACE, as a disorder including altered mental status, ataxia, headache, loss of consciousness, and seizures, is a serious complication of high altitude. As the symptoms suggest, rapid identification is key to reducing other problems, including death, from HACE. The use of ultrasound is relatively new in assisting with diagnosis, but an increase in optic nerve diameter on ultrasound above 5 millimeters indicates that there is a good chance of brain swelling (or cerebral edema) and subsequent increased intracranial pressure. Identifying this early allows for rapid decision making the descent to a lower altitude or using a more rapid evacuation method (helicopter or rapid ground transport). Increased intracranial pressure can also result from head injury or trauma and thus can be useful in settings where an injury may have occurred. This makes this a tool that could be invaluable in search and rescue operations or for first responders (Shookahi et al., 2020).
Gargani, 2019
Keeping these benefits in mind, remember that diagnostic imaging is a support tool and not the complete answer to all health problems. Hopefully soon we will see this tool being used with more frequency to help aid our healthcare providers in determining a more accurate cause of symptoms!
References
Chiu, L., Jairam, M. P., Chow, R., Chiu, N., Shen, M., Alhassan, A., Lo, C.-H., Chen, A., Kennel, P. J., Poterucha, T. J., & Topkara, V. K. (2022). Meta-Analysis of Point-of-Care Lung Ultrasonography Versus Chest Radiography in Adults With Symptoms of Acute Decompensated Heart Failure. The American Journal of Cardiology, 174, 89–95. https://doi.org/10.1016/j.amjcard.2022.03.022
Heldeweg, M. L. A., Smit, M. R., Kramer-Elliott, S. R., Haaksma, M. E., Smit, J. M., Hagens, L. A., Heijnen, N. F. L., Jonkman, A. H., Paulus, F., Schultz, M. J., Girbes, A. R. J., Heunks, L. M. A., Bos, L. D. J., & Tuinman, P. R.. (2022). Lung Ultrasound Signs to Diagnose and Discriminate Interstitial Syndromes in ICU Patients: A Diagnostic Accuracy Study in Two Cohorts*. Critical Care Medicine, 50(11), 1607–1617. https://doi.org/10.1097/ccm.0000000000005620
Shokoohi, H., Pyle, M., Kuhl, E., Loesche, M. A., Goyal, A., LeSaux, M. A., Boniface, K. S., & Taheri, M. R. (2020). Optic Nerve Sheath Diameter Measured by Point-of-Care Ultrasound and MRI. Journal of neuroimaging : official journal of the American Society of Neuroimaging, 30(6), 793–799. https://doi.org/10.1111/jon.12764
Yang, W., Wang, Y., Qiu, Z., Huang, X., Lv, M., Liu, B., Yang, D., Yang, Z., & Xie, T.. (2018). Lung Ultrasound Is Accurate for the Diagnosis of High-Altitude Pulmonary Edema: A Prospective Study. Canadian Respiratory Journal, 2018, 1–9. https://doi.org/10.1155/2018/5804942
Acute mountain sickness (AMS) is a condition that can occur when individuals ascend to high altitudes rapidly, typically above 2,500 meters (8,200 feet). The symptoms of AMS are due to the body’s struggle to adapt to the decreased oxygen levels at higher elevations. More specifically, the symptoms are caused by cerebral vasodilation that occurs in response to hypoxia, in an attempt to maintain cerebral perfusion.1
The typical symptoms of AMS include headache, nausea, vomiting, anorexia, and fatigue. In children the symptoms are less specific including increased fussiness, crying, poor feeding, disrupted sleep, and vomiting. Symptom onset is usually 6-12 hours after arrival to altitude but this can vary.
AMS affects children, adults, males and females equally, with a slight increased incidence in females. It is difficult to believe, but physical fitness does not offer protection against AMS. However, people who are obese, live at low elevation, or undergo intense activities upon arrival to elevation are at increased risk.1
Treatments for Acute Mountain Sickness
Descending
Descending and decreasing altitude is a vital treatment for people with severe symptoms of AMS. By decreasing altitude there will be more oxygen in the air and symptoms will not be as severe..2
Oxygen
Since the main cause of AMS is hypoxia, oxygen supplementation is an effective treatment when descent is not wanted or possible. Supplemental oxygen even at .5L to 1L per hour can be effective in reducing symptoms.1 It can be prescribed for short periods of time or to be used only during sleep In the central Colorado Rockies, this may be a practical solution for “out of towners” who have traveled up to the town of Leadville (10,158’/3096m) for vacation, but in an austere environment supplemental oxygen may not be a reasonable treatment option. There should be symptomatic improvement within one hour.
Acetazolamide
Acetazolamide is a carbonic anhydrase inhibitor which causes increased secretion of sodium, potassium, bicarb, and water. This mechanism of actions lends beneficial to the treatment of AMS because it decreases the carbonic anhydrase in the brain. 3There is evidence to support the use of acetazolamide in the prevention of AMS, but minimal evidence pointing towards it’s role in treatment. Dosing is inconsistent but is usually prescribed at 125-250mg BID.
Hyperbaric Therapy
Many people consider hyperbaric chambers to be large structures in hospitals, however there are portable and lightweight hyperbaric chambers that can be used in austere environments or during expeditions. The mechanism of action of hyperbaric therapy is a simulated decrease in elevation, of approximately 2500 meters. These chambers will remove symptoms within approximately one hour of use but symptoms are likely to return. They are useful in the field but not frequently required in a hospital setting.1
Lynde Tucker is a third year medical student who grew up in Lake Tahoe California, and moved to Colorado for medical school. She is grateful for the opportunity to be back living in the mountains and working in a mountain community.
My love for hiking developed during my childhood explorations of the breathtaking landscapes of the Sierra Nevada. As I ventured into the rugged mountains and hiked along scenic trails, I couldn’t help but feel a deep connection with nature. However, my passion for hiking was not without its moments of caution. On several occasions, I witnessed the awe-inspiring yet intimidating power of lightning storms dancing across the vast mountain skies. These encounters instilled in me a profound curiosity about the risks associated with lightning strikes in high-altitude regions.
When I moved to Colorado for PA school, my awareness of the dangers posed by lightning strikes grew even stronger. The dramatic topography and frequent thunderstorms in Colorado amplify the risk for individuals exploring high-altitude areas. It was during my last clinical rotation at a burn unit that I had the opportunity to care for several patients who had been struck by lightning. Witnessing the effects firsthand fueled my determination to educate the public about the actionable steps they can take to stay safe during lightning storms.
Lightning strikes
Lightning possesses an immense amount of energy, with a voltage of over 10 million volts (in comparison, most car batteries measure 12.6 V).1 Additionally, a lightning bolt reaches incredibly high temperatures, reportedly up to 30,000 Kelvin (53540.33 F).1 Lightning injuries occur in different ways, including as direct strikes, side splash, contact injuries, or ground current.
Direct strikes are uncommon, accounting for only 5% of cases, and happen when a person is directly struck by lightning.2
Contact injuries occur when a person touches an object that is struck by lightning. 2
Side splash injuries occur when the current jumps or “splashes” from a nearby object and then follows the path of least resistance to reach the individual. These injuries make up about 1/3 of all lightning related injuries. 2
Ground current is the most prevalent cause of injury, accounting for half of all cases, and occurs when lightning strikes an object or the ground near a person and subsequently travels through the ground to reach the individual. 2
In Colorado, an average of 500,000 lightning flashes hit the ground each year. Based on data since 1980, lightning causes 2 fatalities and 12 injuries per year throughout the state.3According to data since 1980, lightning causes an average of 2 fatalities and 12 injuries annually throughout the state.3 Colorado ranked third in the United States for the number of lightning fatalities between 2005 and 2014, as depicted in Figure 1.
Fig. 1. Lightning fatalities by state. 3
The high number of injuries attributed to lightning in Colorado can be influenced by several factors. One of these factors is the easy access to high elevation terrain, such as 14ers (mountains with a peak elevation of at least 14,000 feet). This accessibility allows inexperienced outdoor enthusiasts to venture into potentially dangerous situations due to their lack of knowledge and preparation.
For instance, individuals who are not familiar with summer weather patterns may embark on a hike above the tree line late in the day, underestimating the risk of a storm forming. This lack of understanding puts them in an exposed and perilous position should adverse weather conditions arise.
Even with thorough preparation and extensive knowledge of weather patterns, it is still possible to find oneself in a situation where you have to weather a storm. Given that a significant proportion of Colorado’s hiking trails are located above the tree line, where appropriate shelter is sparse, hikers are more susceptible to lightning strikes in these exposed areas.
Pathophysiology of Lightning Strike Injuries
The overall ratio of lightning injuries to deaths is 10:1 and there is a 90% chance of sequelae in survivors.4 The primary mechanism of injury in lightning strikes is the passage of electrical current through the body. The high voltage and current can cause tissue damage through several mechanisms, including thermal injury, electrical burns, and mechanical disruption of tissues. The severity of the injury depends on factors such as the voltage and current of the lightning bolt, the duration of contact, and the pathway the current takes through the body.
Lightning strikes can cause various types of injuries, with cardiac and respiratory arrest being the most common fatal complications.5 The path of least resistance determines the flow of electricity through different organs in the body, with nerves being the most conductive, followed by blood, muscles, skin, fat, and bone. 5 When lightning strikes, the electrical surge can induce cardiac arrest and cessation of breathing by affecting the medullary respiratory center. As a result, most patients initially present with asystole and may progress to different types of arrhythmias, commonly ventricular fibrillation. 5
Interestingly, there have been case reports documenting successful resuscitation of lightning strike victims who were initially apneic and pulseless for as long as 15 to 30 minutes. 5This has led to the recommendation that in the immediate aftermath of a lightning strike, individuals who appear to be dead should be prioritized for treatment.
Superficial skin burns are experienced by around 90% of lightning strike victims, but deep burns are less common, occurring in less than 5% of cases. A characteristic skin manifestation of a lightning strike is the Lichtenberg figure, which is considered pathognomonic. Neurological symptoms can also occur, including keraunoparalysis, which is a transient paralysis affecting the lower limbs more than the upper limbs. This paralysis is often accompanied by sensory loss, paleness, vasoconstriction, and hypertension, and is thought to result from overstimulation of the autonomic nervous system, leading to vascular spasm. In most cases, this paralysis resolves within several hours, but in some instances, it may last up to 24 hours or cause permanent neurological damage. 5
Additionally, it is common for lightning strike victims to have a perforated tympanic membrane (eardrum) or develop cataracts immediately following the incident. These injuries to the ear and eyes are associated with the intense energy of the lightning discharge.6
What can hikers do to stay safe?
Preparation
Monitor weather forecasts: Stay updated on weather conditions before engaging in outdoor activities, especially in areas prone to thunderstorms. Pay attention to thunderstorm warnings or watches issued by local authorities. Having a mobile or handheld NOAA Weather Radio All-Hazards (NWR) can also be helpful as it can transmit life-saving weather information at a moment’s notice.
In Colorado most thunderstorms develop after 11 am, so it is best to plan your trip so that you are descending by late morning.7Fig. 2 shows number of lightning fatalities by time of day in Colorado between 1980 and 2020. The vast majority take place after the 11 am threshold.
Fig. 2 Lightning fatalities in Colorado by time of day3
What to Do If Caught in a Storm
If you can hear thunder, you are close enough to be struck by lightning. Lightning can strike up to 25 miles away from the storm. 7 Once you hear thunder, if possible quickly move to a sturdy shelter (substantial building with electricity or plumbing or an enclosed, metal-topped vehicle with windows up). Avoid small shelters, such as picnic pavilions, tents, or sheds. Stay sheltered until at least 30 minutes after you hear the last clap of thunder.
Fig 3. Areas to avoid when sheltering from lightning.
If you are outdoors and cannot reach a suitable shelter, avoid open areas, hilltops, and high places that are more exposed to lightning strikes. Seek lower ground and stay away from tall objects, such as trees, poles, or metal structures. Bodies of water, including lakes, rivers, pools, and even wet ground, are conductive and increase the risk of a lightning strike. Move away from these areas during thunderstorms. Separate group members by at least 20 ft as lightning can jump up to 15 feet between objects.
If a strike is eminent (static electricity causes hair or skin to stand on end, a smell of ozone is detected, a crackling sound is heard nearby), the current recommendation is to assume “lightning position”, pictured in Fig. 4.
Fig. 4. Lightning position8
To potentially reduce the risk of ground current injury from an imminent lightning strike, another strategy is to insulate oneself from the ground. This can be done by sitting on a pack or a rolled foam sleeping pad. However, it’s important to note that this and the lightning position should be considered a strategy of last resort and not relied upon as the primary means of prevention. Maintaining this position for an extended period can be challenging, and it’s crucial to prioritize seeking proper shelter and following established lightning safety guidelines to minimize the overall risk of injury. 5
Case Study
25 YO F presents to the Burn Unit as a transfer from Cheyenne Regional Medical Center s/p lighting strike. Patient (pt) was caught in a thunderstorm on a hike and sheltered under a tall tree. Suddenly, she felt like she was being lifted up into the air and then dropped. Pt had a brief (<5 sec) loss of consciousness (LOC). When she woke up, she was completely numb and couldn’t move any of her extremities. Witness (friend) states the lightning splashed from the tree to the pt. Pt denies hitting her head with the fall. She denies taking blood thinners. She has no past medical history (PMHx) or past surgical history (PSHx).
Physical exam
Neuro: AOX4, No CN deficit on exam, LE paralysis resolved, LE paresthesia improving but still present
HEENT: L ruptured tympanic membrane, hearing loss on L side
CBC, CMP, troponin were all WNL. Serum hCG negative. CK mildly elevated (222)
EKG showed NSR.
CXR, CT brain, and c-spine neg for acute injury
She was admitted to the UC Health burn center for observation with tele. Her lab work and vitals remained stable throughout her hospitalization. She was evaluated by the trauma team with a negative trauma work up. The day of discharge, she was tolerating a regular diet, ambulating and sating well on room air. She was deemed appropriate for discharge home without patient audiology and ophthalmology follow up.
References
1. US Department of Commerce N. Understanding lightning science. National Weather Service. April 16, 2018. Accessed July 8, 2023. https://www.weather.gov/safety/lightning-science-overview.
2. Cooper MA, Holle RL. Mechanisms of lightning injury should affect lightning safety messages. 21st International Lightning Detection Conference. April 19-20, 2010; Orlando, FL.
3. US Department of Commerce N. Colorado Lightning statistics as compared to other states. National Weather Service. March 4, 2020. Accessed July 7, 2023.https://www.weather.gov/pub/Colorado_ltg_ranking.
4. US Department of Commerce N. How dangerous is lightning? National Weather Service. March 12, 2019. Accessed July 8, 2023. https://www.weather.gov/safety/lightning-odds.
5. Chris Davis, MD; Anna Engeln, MD; Eric L. Johnson, MD; Scott E. McIntosh, MD, MPH; Ken Zafren, MD; Arthur A. Islas, MD, MPH; Christopher McStay, MD; William R. Smith, MD; Tracy Cushing, MD, MPH. Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Lightning Injuries: 2014 Update. WILDERNESS & ENVIRONMENTAL MEDICINE. 2014; 25, S86–S95
6. Flaherty G, Daly J. When lightning strikes: reducing the risk of injury to high-altitude trekkers during thunderstorms. Academic.oup.com. Accessed July 8, 2023. https://academic.oup.com/jtm/article/23/1/tav007/2635599.
7. NWS Colorado Offices – Boulder G. Colorado Lightning Awareness Week june 19-25, 2022. ArcGIS StoryMaps. June 25, 2022. Accessed July 8, 2023. https://storymaps.arcgis.com/stories/11d021f1b800429a869ead2dc32c0f96.
8. McKay B and K. How to survive A lightning strike: An illustrated guide. The Art of Manliness. April 25, 2022. Accessed July 8, 2023. https://www.artofmanliness.com/skills/outdoor-survival/how-to-survive-a-lightning-strike-an-illustrated-guide/.
Sophia Ruef is a Physician Assistant student at Red Rocks Community College in Arvada, CO. She grew up on the central coast of California and earned her Bachelor of Science degree inBiology with a concentration in anatomy and physiology from Cal Poly San Luis Obispo. She worked as an EMT and a tech in the Bay Area after her undergraduate education. In her free time, she enjoys hiking, backpacking, canyoneering, and spending time with family and friends.
Often, at high altitude we hear complaints of gas pain and increased flatus in our infant population. Parents often wonder, are we doing something wrong? Is my child reacting to breastmilk, or showing an intolerance to certain foods? Actually there is another explanation for increased flatus and gas pain in the high-altitude region of Colorado.
The term HAFE was coined by Dr. Paul Auerbach and Dr. York Miller and published in the Western Journal of Medicine in 1981. Their discovery began In the summer of 1980, when the two doctors were hiking in the San Juan Mountains of Colorado on a quest to summit three 14ers. During their ascent they noticed that something didn’t smell right! As the pair continued to emit noxious fumes, they began to put their scientific brains to work and discovered HAFE. The symptoms include an increase in frequency and volume of flatus, or in other terms an increase in toots! We all have familiarity in watching our bag of potato chips blow up when reaching altitude or our water bottle expanding as we head into the mountains. This reaction is due to a decrease in barometric pressure. Based on Boyle’s law, decreased barometric pressure causes the intestinal gas volume to expand, thus causing HAFE (Skinner & Rawal, 2019).
To my surprise, a gas bubble the size of a walnut in Denver, Colorado (5280 ft) would be the size of a grapefruit in the mountain region of Summit County, CO (8000+ ft)! Trapped gas is known to lead to discomfort and pain. The use of simethicone may have merit in mitigating the effects of HAFE. Simethicone works by changing the surface tension of gas bubbles, allowing easier elimination of gas. This medication, while benign, can be found over the counter and does not appear to be absorbed by the GI tract (Ingold, C. J., & Akhondi, H., 2022).
While this phenomenon may not be as debilitating as high-altitude pulmonary edema (HAPE), it deserves recognition, as it can cause a significant inconvenience and discomfort to those it inflicts. As the Radiolab podcast explained in their episode The Flight Before Christmas , expelled gas in a plane or car when driving up to the mountains can be embarrassing. While HAFE can be inconvenient, it is a benign condition and a matter of pressure changes rather than a disease or pathological process. We would love to talk more about HAFE at Ebert Family Clinic if you have any questions or concerns!
A bald eagle flies toward its nest atop a bare lodgepole pine.
As always, stay happy, safe, and healthy 😊
Taylor Hollingsworth is finishing her final semester as a family nurse practitioner (FNP) student at Georgetown University. Originally from the east coast, Taylor plans to start her FNP career in North Carolina close to family. She has a passion for pediatric and family wellness and has worked as a pediatric intensive care unit nurse for 6 years! In her free time, Taylor loves to hike, fly fish, run, and spend time with her fiancé Logan.
References
Auerbach, P. & Miller, Y. (1981). High altitude flatus expulsion. The Western Journal of Medicine, 134(2), 173-174.
From backpacking and camping to skiing and snowboarding, there are plenty of activities outdoors in the Colorado high country. If you find yourself wandering around and lost without food in the mountains, there are several wild plants that you can eat.
However, before you consume the delectable greens, there are a few precautions to take.
Moose shopping
Do not eat any wild plants unless you can positively identify them. There are iOS and Android apps that you can download prior to your hike to help distinguish plants, such as PictureThis and NatureID.
Be aware of environmental factors such as pollution or animal waste. Avoid popular wild animal gathering areas.
Make sure you’re not allergic to the plant by rubbing it against your skin and observing for a reaction. If so, do not eat the plant. Before ingesting a large quantity, eat a small amount and check for a reaction.
It may be difficult to cook if you did not come prepared with a portable stove, pots, and water, which could limit ways to enjoy vegetation. Here is a list of edible plants, how to identify them, where can they be found, and which part you can eat.
Wild plants
Dandelions (Taraxacum officinale): yellow ray florets that spread outward from center with toothy, deep-notched, hairless basal leaves and hollow stems. They can be found everywhere and anywhere. Every part of the dandelion plant is edible including the leaves and roots.
Pineapple Weed/ Wild Chamomile (Matricaria discoidea): the flower heads are cone-shaped and yellowish-green and do not have petals. Often found near walking paths and roadsides, harvest away from disturbed, polluted areas. If you’re feeling anxious about being lost, pineapple weed promotes relaxation and sleep and serves as a digestive aid.
Fireweed (Epilobium angustifolium): vibrant fuchsia flowers. Grows in disturbed areas and near recent burn zones. Eat the leaves when they are young as adult leaves can stupefy you. Young shoot tips and roots are also edible.
Wild onions (Allium cernuum): look for pink, lavender to white flowers with a strong scent of onion. They grow in the subalpine terrain and are found on moist hillsides and meadows. Caution: do not confuse with death camas. If it doesn’t smell like an onion and has pink flowers, it is not likely an onion.
Cattails (Typha latifolia or Typha angustifolia): typically 5-10 feet tall. Mature flower stalks resemble the tail of a cat. Grow by creek, river, ponds, and lakes. This whole plant is edible, from the top to the roots. Select from pollution-free areas as it is known to absorb toxins in the surrounding water.
Wild berries:
Wild strawberries (Fragaria virginiana): they are tiny compared to store-bought. Can be identified by their blue-green leaves; small cluster of white flowers with a yellow center; and slightly hairy, long and slender red stems.
Huckleberries (Vaccinium spp): They grow in the high mountain acidic soil and flourish in the forest grounds underneath small, oval-shaped, pointed leaves. They resemble blueberries and have a distinguishable “crown” structure at the bottom of the berry. They can be red, maroon, dark blue, powder-blue, or purple-blue to almost black, and they range from translucent to opaque.
Oregon grapes (Mahonia aquifolium): powder-blue berries, resembling juniper berries or blueberries, with spiny leaves similar to hollies that may have reddish tints.
Fun fact: The roots and bark of the plant contain a compound called berberine. Berberine has antimicrobial, antiviral, antifungal, and antibiotic properties.
Mushrooms
True morels (Morchella spp.): cone-shaped top with lots of deep crevices resembling a sponge. They will be hollow inside. A false morel will have a similar appearance on the outside but will not be hollow on the inside and are toxic. Morels are commonly found at the edge of forested areas where ash, aspen, elm, and oak trees live. Dead trees (forest wildfires) and old apple orchards are prime spots for morels.
Porcini (Boletus edulis): brown-capped mushrooms with thick, white stalks. Found at high elevations of 10,500 and 11,200 ft in areas with monsoon rains and sustained summer heat.
There are many more edible plants, flowers, berries, and mushrooms in the mountains. These are just 10 that can be easily identifiable and common in the Western Colorado landscapes. I recommend trying out the apps listed above and reading “Wild Edible Plants of Colorado” by Charles W. Kane, which includes 58 plants from various regions, each with details of use and preparation. Hopefully this post made you feel more prepared for your next adventure.
Resources:
Davis, E., 2022. Fall plant tour: Frisco, CO | Wild Food Girl. [online] Wildfoodgirl.com. Available at: <https://wildfoodgirl.com/2012/eleven-edible-wild-plants-from-frisco-trailhead/> [Accessed 10 July 2022].
McGuire, P., 2022. 8 Delicious Foods to Forage in Colorado | Wild Berries…. [online] Uncovercolorado.com. Available at: <https://www.uncovercolorado.com/foraging-for-food-in-colorado/> [Accessed 10 July2022].
Rmhp.org. 2022. Edible Plants On The Western Slope | RMHP Blog. [online] Available at: <https://www.rmhp.org/blog/2020/march/foraging-for-edible-plants> [Accessed 10 July 2022].
Lifescapecolorado.com. 2022. [online] Available at: <https://lifescapecolorado.com/2014/01/edible-plants-of-colorado/> [Accessed 10 July 2022].
Pfaf.org. 2022. Plant Search Result. [online] Available at: <https://pfaf.org/user/DatabaseSearhResult.aspx> [Accessed 10 July 2022].
Cindy Hinh is a second-year Physician Assistant student at Red Rocks Community College in Arvada, CO. She grew up in southern Louisiana and received her undergraduate degree in Biology from Louisiana State University. Prior to PA school, she was a medical scribe in the emergency department and an urgent care tech. In her free time, she enjoys baking, cooking, going on food adventures, hiking, and spending time with family and friends.
Have you thought of what it would be like living in the mountains year-round? Medical professionals find it is important to look at what living at high elevations can do to the human body. One activity heavily affected is sleep. As mentioned in previous blog posts, visitors often have trouble falling asleep, staying asleep, and feeling rested in the morning. A recent study published in Physiological Reports measured the effects of sleeping patterns at high elevation. The participants experienced a simulated elevation inside a hyperbaric chamber. This mimicked sleeping at elevations of 3000 meters (9,842 feet) and 4050 meters (13,287 ft) for one night and then sleeping at sea level for several nights to establish a baseline for the research participants. Participants exercised for 3 hours in the hyperbaric chamber allowing researchers to observe how the lower oxygen concentrations affected their ability to perform strenuous tasks. The group that slept in a simulated 4050 meter environment had an increased heart rate that was 28% higher and an oxygen saturation 15% lower than the 3000 meter participants. When comparing sleep itself, the group at 4050 meters had 50% more awakening events throughout each night. This goes along with previous research on this blog that states that people who sleep at high altitude complain of insomnia and frequent awakening when first arriving at high elevation.
These numbers increase even more dramatically when compared to participants at sea level. Related symptoms reported during this study showed the incidence of acute mountain sickness occurred in 10% of the participants at a simulated 3000 meters, increasing to 90% at 4050 meters. As mentioned, the average heart rate increases and oxygen saturation decreases as the elevation increases. The baseline heart rate at sea level was 62 beats per minute, increasing to 80 at 3000 meters and 93 at 4050 meters. Ideally health care providers aim to oxygenate vital organs by keeping the oxygen saturation level between 92-100%. The lower the oxygen level the harder it is to keep organs properly profused. Age, health status, and place of residence are taken into consideration when examining study reports. Oxygen saturation at sea level was 98% decreasing to 92% at 3000 meters and 84% at 4050 meters.
As mentioned in a previous post by Dr. Neale Lange, sleeping at high altitudes can be hard due to the frequent awakenings and nocturnal hypoxia caused by the low oxygen levels at higher elevation. This study reiterates these findings with the results of the average oxygen saturation at 3000 meters being around 92%. Dr. Lange also found that sleep apnea was often more prominent and had more negative effects on the human body in environments that were lower in oxygen. This study agrees with that statement finding that people with sleep apnea had twice the hourly awakenings compared to those at higher elevation that did not have sleep apnea. Dr. Lange also pointed out that the contribution of hypobaric atmosphere to symptoms at altitude as opposed to pure hypoxemia is unknown. Frisco, Colorado is at an elevation of 2800 meters. Ongoing research at Ebert Family Clinic including residents and visitors along with laboratory studies such as this one can guide decisions about interventions and treatment to improve sleep and help us enjoy our time in the mountains.
References
Figueiredo PS, Sils IV, Staab JE, Fulco CS, Muza SR, Beidleman BA. Acute mountain sickness and sleep disturbances differentially influence cognition and mood during rapid ascent to 3000 and 4050 m. Physiological Reports. 2022;10(3). doi:10.14814/phy2.15175
Blog post: HOW DO YOU DEFINE A GOOD NIGHT’S SLEEP?:AN INTRODUCTION TO THE SLEEPIMAGE RING, AN INTERVIEW WITH DR. NEALE LANGE
Casey Weibel is a 2nd year student at Drexel University, born and raised in Pittsburgh, Pennsylvania. He went to Gannon University for his undergrad and got a degree in biology. Before PA school, Casey was an EMT. He enjoys hiking and kayaking and is a big sports fan.
Wild animals, storms, avalanches, cold, high altitude pulmonary edema or cerebral edema, falls, fires and injuries are the most common dangers in the mountains. I’ve climbed 19 different mountains in Colorado over 14,000′, and some of them more than once, making for 28 successful ascents. But I called Summit County Search and Rescue Saturday for something I was not expecting: deep wet snow that trapped me less than 2 miles from the trailhead.
Summit County trail map
It was a bright, warm day — I had even left my hand warmers at home. My plan was to hike from Miners Creek trailhead in Frisco to Gold Hill Trailhead north of Breckenridge which is about a 6- or 7-mile trip one way. I had hiked from both ends in previous weeks and saw the turn-off had snow and no tracks. I attached my snowshoes to my backpack with plans to turn up towards Gold Hill if there were tracks, and there were.
After 4 miles I was out of the forest on top with gorgeous 360˚ views of mountains. I no longer saw the trail markers or tracks so set out across the open space with my snowshoes sinking into the snow every 10 to 20 feet. The trail maps and GPS on my phone were sketchy, only showing I was very near the Colorado Trail. I turned down a logging road to get out of the wind thinking the snow would be packed. I could see several open areas that I thought would take me to the familiar trails to Gold Hill.
After an hour sinking into deep snow I noticed I had only one snowshoe. I backtracked 100 feet following the tracks to find it, dug at several spots where I had sunk the deepest but never found it. I went back towards the Colorado Trail but could not progress, having to dig my boot out of deep snow several times. I tried to backtrack in my footsteps but couldn’t get far. I had now covered a mile in an hour and a half, my phone showing I was only 48 minutes from the Gold Hill trailhead.
So I called 911, thinking they could drive a snowmobile up to get me. Bad news: the vehicle would just sink the same way I was. The 911 operator knew me and the Summit County Search & Rescue mission coordinator Mark Svenson was in touch several times as I waited from 3:17 until about 6 pm when the crew arrived with skis and extra snowshoes. My Blue Heeler Isa and I stayed within one foot of a small pine tree where we found firm footing after rolling through the deep, soft snow. Luckily the sun kept us warm until 5 pm, and I had food and water. My gloves and boots were soaked so my feet were very cold and I tried to keep Isa lying over my legs or feet. I had a plastic rain shield extension that I could pull out and sit on in a pocket of the backpack that one of my students had gifted me.
The rescuers had water, snacks, dry socks, dry gloves, gators and snowshoes. They had packed down the trail but there were still times we post-holed on the way down. We arrived at the rescue vehicle as darkness fell. Special Operations Sheriff SJ Hamit waited with Mark and other SCSR staff to welcome us. One of the rescuers told me how happy he was that I was still smiling when they arrived!
Summit County Search & Rescue team, Sheriff Hamit on the left, Dr. Chris far right.
What did I learn? Stay out of deep, wet snow even if it means going back the long way. Bring extra socks and gloves. Buy gators.
I was not afraid because I knew they were coming before dark. I do feel exhilarated that I was able to do such a challenging hike without any pain or blisters, that my knees were strong enough to extract my feet from the deep snow so many times, and that Isa was with me to warn if any animals were near and announce when the rescuers arrived.
Christine Ebert-Santos, MD, MPS is the founding physician and president of Ebert Family Clinic in Frisco, Colorado, where she leads high altitude research in addition to running a full-time family practice. Isa is a two-year-old blue heeler and Dr. Chris’s familiar and guardian angel.
Prior to COVID-19, I would hike the beautiful mountains of Colorado known as 14ers, a name given to these mountains for being over 14,000 ft. I, like most high-altitude travelers faced the more common concerns associated with hiking such as acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE). With the increase in high-altitude travel, I wondered if there are any new precautions that we should consider before resuming the activities that we love.
The purpose of this article is to highlight the recommendations for patients who wish to return to high-altitude travel after a COVID infection. Not everyone needs an evaluation after a COVID infection. The recommendations noted in this article are based on the duration and severity of the illness of each individual person.
So, who should receive an evaluation before high-altitude travel?
Individuals with symptoms after 2 weeks of a positive COVID-19 test without hospitalization,
Individuals with symptoms after 2 weeks after hospital discharge,
Anyone who required care in the intensive care unit (ICU), and
Anyone who developed myocarditis or thromboembolic events. The recommendations are to undergo pulse oximetry at rest and with activity, spirometry, lung volumes, and diffusion capacity for carbon monoxide(DLCO), chest imaging, electrocardiography (EKG), B-type natriuretic peptide, high sensitivity cardiac troponin (hsTn), and echocardiography.
It is expected that people with lower oxygen levels (hypoxemia) at rest or with exertion in lower elevations will experience greater hypoxemia with ascent to high altitude. It has been shown that ascent to high altitude causes a decrease in barometric pressure leading to a decrease in ambient and inspired partial pressure of oxygen. The decrease in partial pressure of oxygen in alveoli (PaO2) will trigger vasoconstriction of pulmonary arterioles that slows the rate of oxygen diffusion and activates chemoreceptors that increase minute ventilation from hypoxia. However, it is still unclear whether people with low oxygen levels at low elevations are at greater risk for acute altitude illness after ascent. The recommendation is to monitor pulse oximetry after arrival of high altitude.
Individuals with abnormal lung function tests don’t have to avoid high altitude travel as previous studies have shown that patients with COPD with abnormal lung functions tolerate exposure. Furthermore, in people with mild to severe COVID-19 symptoms, the lung mechanic markers such as forced expiratory volume (FEV1), forced vital capacity (FVC) and total lung capacity (TLC) normalize in up to 150 days of infection. However, if individuals have severe limitations with exercise capacity, they should monitor their oxygen levels with pulse oximetry after ascent. Reduction in exercise capacity is possible after COVID infection and depends on the severity of the illness. Blokland et al., 2020 has shown that previously intubated individuals had a median VO2 max of 15ml/kg per min (average male 35 to 40 and average female 27 and 30), roughly 57% predicted immediately after hospitalization.
In acute hypoxia, the heart rate increases, which leads to an increase in cardiac output. Individuals with reduced ventricular function from COVID infection do not have to avoid travel. Previous research has shown that individuals with heart failure can tolerate exercise with hypoxia. Moreover, data has shown that individuals with COVID infection maintain preserved left ventricular function and only 3% show a reduced ejection fraction. Individuals with abnormal EKG rhythms and ischemia should be referred to cardiology. If high sensitivity troponin was abnormally elevated, this would require evaluation for myocarditis with a cardiac MRI. Knight et al., (2020), found that 45% of patients with unexplained elevations of high-sensitivity troponin were found to have myocarditis during hospitalization. It is still unclear how long these abnormalities will last and how it will affect people.
A concerning finding on ECHO is pulmonary hypertension, as previous research has shown an increased risk in developing HAPE. A study reported that 10% of patients hospitalized for COVID without mechanical ventilation had right ventricular dysfunction for over 2 months. Several studies reported that 7-10% of individuals may have pulmonary hypertension after COVID infection. A vasodilating drug such as nifedipine can be given prophylactically if pulmonary hypertension is unrelated to left heart dysfunction but nifedipine can worsen hypoxemia.
The recommendation for patients who developed myocarditis from a COVID infection is to have an ECHO, Holter monitor, and exercise EKG 3-6 months after illness. Travel can resume after a normal ECHO, no arrhythmias on exercise EKG, and after inflammatory markers (ESR and/or CRP) have normalized. Previous studies suspected that areas with low atmospheric pressures (e.g., high-altitude) that induce hypoxia have increased risk for clot formation. However, this suspicion has never been firmly established; therefore there is no reason to believe that high-altitude will increase the risk for clot formation in individuals who developed an arterial or venous clot from COVID infection.
A few things to consider before planning a high-altitude excursion includes planning to visit areas with access to medical resources or the ability to descend rapidly. If you are new to high altitude, it is recommended to slow the ascent rate. Traveling to high elevations (>4000m) should be avoided until tolerance has developed with moderate elevations (2000-3000m). A more gradual return to physical activity at high altitude is recommended rather than immediate resumption of heavy exertion. As the pandemic subsides and with increase in mountain travel, more research will develop that can better address these risks.
Good news! The Ebert Family Clinic in Frisco, CO provides pulse oximeters for free. So, make sure to visit and grab your pulse oximeter before your next ascent.
Quick Summary of Recommendations
Individuals who require evaluation prior to high-altitude travel:
Individuals who have symptoms after 2 weeks of a positive COVID-19 test without hospitalization
Individuals who have symptoms after 2 weeks after hospital discharge
Any patient who required care in the intensive care unit (ICU)
Any patient who developed myocarditis or thromboembolic events
General recommendations for anyone before high-altitude travel:
Monitor pulse oximetry after arrival of high altitude, and access care or descend if symptoms worsen.
Rest and avoid high-altitude travel for at least 2 weeks after a positive test, and consider a gradually return to physical activity at higher altitudes.
All individuals planning high-altitude travel should be counseled on how to recognize, prevent, and treat the primary forms of acute altitude illness (AMS, HACE, and HAPE)
Limit the extent of planned exertion after ascent and, instead, engage in graded increases in activity that allow the individual to assess performance and avoid overextending themselves.
Reasons to forgo high-altitude travel:
Severely elevated pulmonary artery pressures may be a reason to forego high-altitude travel altogether.
High-altitude travel should likely be avoided while active inflammation is present in myocarditis.
Patients who experienced arterial thromboembolic events due to COVID-19, (e.g. myocardial infarction or stroke) should defer return to high altitude for several months after that event or any associated revascularization procedures.
References:
Andrew M. Luks and Colin K. Grissom. Return to High Altitude After Recovery from Coronavirus Disease 2019. High Altitude Medicine & Biology. http://doi.org/10.1089/ham.2021.0049
Christensen CC, Ryg M, Refvem OK, Skjønsberg OH. Development of severe hypoxaemia in chronic obstructive pulmonary disease patients at 2,438 m (8,000 ft) altitude. Eur Respir J. 2000 Apr;15(4):635-9. doi: 10.1183/09031936.00.15463500. PMID: 10780752.
Blokland IJ, Ilbrink S, Houdijk H, Dijkstra JW, van Bennekom CAM, Fickert R, de Lijster R, Groot FP. Inspanningscapaciteit na beademing vanwege covid-19 [Exercise capacity after mechanical ventilation because of COVID-19: Cardiopulmonary exercise tests in clinical rehabilitation]. Ned Tijdschr Geneeskd. 2020 Oct 29;164:D5253. Dutch. PMID: 33331718.
Jesse Santana is a second-year PA student at Red Rocks Community College in Denver, Colorado. He grew up in Colorado Springs, CO and attended the University of Colorado-Colorado Springs where he earned a bachelor’s in Biology and Psychology. Jesse worked as a Certified Nursing Assistant for two years before pursuing a Master’s in Biomedical Sciences at Regis University in Denver. Shortly after, he coordinated clinical trials in endocrinology and weight loss as a Clinical Research Coordinator at University of Colorado Anschutz Medical Campus. He enjoys hiking Colorado’s 14ers, spending time with family and friends, and camping.
