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
The common thought that mosquitos do not live at higher elevations may no longer ring true. With temperatures slowly rising, we are seeing a rise in mosquito populations both at higher elevations and farther north than we have before.1 With the ever-changing climate, mosquitos are having luck finding their ideal conditions with standing water, higher temperature, and humidity at higher elevations.
As of June 27, 2024, the state of Colorado had already seen its first case of West Nile Virus for the year, something that does not usually occur until late in the summer; and in 2023, Colorado dealt with its worst West Nile virus outbreak ever recorded.2 As we are beginning to see more and more mosquitos in our community, people are looking for the best and safest mosquito repellents.
We all know the most common big hitters when it comes to bug spray; DEET-containing bug sprays and those that say DEET-free. If your mom is like mine and used to tell you that Avon Skin So Soft is a great mosquito repellent, I’m here to help you determine if it actually does work. A study published in the BC Medical Journal compared DEET-containing mosquito repellent, Avon Skin So Soft bath oil, and a “special mixture” containing a combination of eucalyptus oil, white vinegar, Avon Skin So Soft, and tap water, against a placebo. They found that both DEET and Avon Skin So Soft protected against mosquito bites significantly more than the “special mixture.” In this study, Avon Skin So Soft was 85% as effective as DEET at protecting against mosquito bites. Looking strictly at the numbers, DEET had 0 mosquito events (both bites and mosquitos landing on the skin), Avon Skin So Soft bath oil had 6 events, the “special mixture” had 28 events, and the placebo had 40 events.3
From personal experience, I have tested out Avon Skin So Soft and its mosquito repellent properties. In August 2019 my best friend and I ventured halfway across the world to Thailand for a post-undergraduate adventure. With limited packing room and a dislike for the smell of bug spray, I brought Avon Skin So Soft body moisturizer with me and was pleasantly surprised with how well it kept the mosquitos away. While I do recall getting just a few mosquito bites during my time there, I will definitely be bringing it with me for my next post-graduation adventure after finishing PA school.
As Colorado is seeing a rise in mosquitos earlier in the season it’s time to check our bug sprays. If you are interested in trying something new, or if you prefer DEET-free products, Avon Skin So Soft might be worth a try. With all of the hype that Avon Skin So Soft bath oil has as an effective insect repellent, the company has made a specific bug repellent line of products that claims to protect against mosquitos, deer ticks, black flies, gnats, and biting midges.
And for our furry friends that tag along with us on all of our outdoor adventures, remember that they too can get bitten by pesky insects. They are still susceptible to mosquito bites as well as ticks and fleas. At altitude we see less ticks and fleas in our communities due to the dry air, however they are still present, so it is important to protect your animals like you do yourself. Some veterinarian recommended tick and flea prevention include Simparica Trio or Nexgard chewables.
Founder of Ebert Family Clinic in Frisco, Colorado at 9000′, Christine Ebert-Santos, MD, MPS spent a part of her Spring 2024 backpacking across Norway:
At 2,469m (8,100 feet), Galdhøpiggen mountain in Norway is not high enough to cause altitude sickness for most people. The 300 mountain peaks over 2000m make Norway a popular destination for downhill skiing and snowboarding, as well as Nordic skiing. The long days of sunshine at this latitude allow skiing in swimsuits and summer clothes in the spring.
Norway also has the largest glacier in Europe, Jostedalsbreem. Briksdalbreen is a finger of this glacier that is a short hike in the Jostedalsbreem National Park. There are 1,600 glaciers covering one percent of Norway. Several have resorts advertising summer skiing for the whole family.
There are 900 tunnels in Norway, including the longest tunnel in the world. Compared to Eisenhower Tunnel in Colorado at 11,112 feet elevation and 1.67 miles long, Laerdal tunnel, opened in 2000, is 15 miles long with pullouts featuring colored lighting to imitate the sunrise. Some of these tunnels, like the one between the airport and downtown Oslo, go as deep as 958 feet underwater. All have phones and excellent cell phone reception. In fact, we experienced excellent reception everywhere in Norway despite the mountains and tunnels, in contrast to my sister’s house in Centennial, Colorado and many parts of Colorado.
Our last night in Norway was special. We drove two hours over narrow roads, through tunnels, over one lane bridges to Ronde Island. With a population of 150, the island is a famous bird sanctuary. We arrived just in time to see the puffins return to their nests at 8 pm. These colorful birds spend their lifespan of 30-40 years flying over the ocean, sleeping on the waves, returning to land once a year with the same mate.
The fact that Norway provides such amazing access to even this tiny town tells me how much they respect individuals. They have an average lifespan of 83 years (76 years in the USA), universal health care, one year paid leave for parents with a new baby, universal pensions, free education through college, daycare for less than $15/day, and much more. How much do they pay in taxes, you might ask? Less than what we pay when you consider the cost of health insurance, day care, school loans, with 60% of Americans who do not have anything saved for retirement.
“‘The first sign is usually a cough,’ Ebert-Santos said. ‘Followed by shortness of breath with any effort — even just walking — and fatigue. You just want to lie on the couch.’
If left untreated the early warning signs of high altitude pulmonary edema can rapidly progress into having fluid build up in the lungs, which will then lead to a patient’s oxygen saturation levels rapidly decreasing. If the individual does not seek treatment quickly, the condition can be fatal.”
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.
During my last week of a clinical rotation at Ebert Family Clinic in Frisco, Colorado, at 9000 feet, I was thrilled to have the opportunity to interview high altitude resident Karen Terrell with physician Dr. Chris Ebert-Santos. During this time, we were able to discuss high altitude pulmonary hypertension, also known as NAPH. This is a condition that Karen has been living with since 2015. NAPH is condition that can affect people that live above 8,200 feet, more than 140 million people live at this altitude worldwide, including the population of Summit County, where the town of Frisco, Colorado is. Pulmonary hypertension is a group of disorders that will typically be diagnosed during a heart catheterization measuring the mean arterial pressure of the right side of the heart. These disorders are broken down into five groups. High altitude pulmonary hypertension is in group three. The primary symptoms that people first notice is extreme fatigue, difficulty getting air upon exertion, and difficulty engaging in their normal exercise routines.
How long have you lived in Summit County [Colorado], and where did you move from originally?
Karen: I grew up in Nebraska, I moved to New York City as soon as I was old enough to leave home. I went to Boulder for school, and then moved to Denver for work. I went to an Outward-Bound Experience, and I fell in love with this area. I have lived in Summit County over 37 years. My kids were born and raised here; they are now in their 30s.
What are some of the things that you love to do in area?
Karen: I downhill ski, I uphill ski, and I cross country ski. Mountain biking is my passion. I downhill bike, that is where you take the gondola to the top of the mountain and then ride your bike down.
When did you start to have symptoms?
Karen: 2015
What were the symptoms that you noticed first?
Karen: Extreme fatigue and erratic pulse, with or without exertion. By the end of a run, I would be so exhausted that I was practically crawling home.
Do have to go on oxygen at any point?
Karen: In 2018 I started using oxygen at night. I still use oxygen at night. In 2020 I started riding and skiing with portable oxygen. When my oxygen columns fail, so do I. It was also during this time I began to work on nasal breathing night and day. I have been doing research on the importance of nasal breathing and retraining the body on how to take in oxygen. Practicing nasal breathing is especially important when you are using a nasal cannula to get oxygen when you are being active.
https://oxygo.life/oxygo-fit
Dr. Chris Ebert-Santos: The standard is “if you’re 50 and you’ve lived here 10 years and you want to live here for another 10 years you should be sleeping on oxygen.”
Between 2015 and 2018 did you have any other symptoms or worsening concerns?
Karen: In 2017 I applied for life insurance. I was denied as I had what I now know is chronic proteinuria. The nephrologist was perplexed as to why someone who is as active as I am and takes no medication is having this condition. The insurance company essentially told me that they would not touch me with a 10-foot pole. This was the “canary in the mine” that made me think something was not right. In 2018, I had a cardiac ablation. The cardiac ablation corrected the erratic heart rate and relieved my extreme fatigue. However, it did nothing for my oxygen saturation.
You mentioned in 2020 that you started to ski and ride your bike with portable oxygen. Did something happen in 2020, besides COVID?
Karen: You know, with everything that I have going on health wise I have been so cautious that I have not ever had COVID. In 2020, I was at an office visit with my PA. I mentioned that biking and skiing at higher elevation with exertion, that I felt flattened and near-dead. My pulse oximeter showed oxygen saturation of low 70’s. My PA freaked out and thought I had Pulmonary Hypertension (as opposed to HAPH) and sent me to a Denver Pulmonary specialist.
What did the pulmonary specialist tell you?
Karen: When I went to the pulmonary specialist, they said my oxygen numbers were fine at Denver’s elevation. The Pulmonologist advised moving to lower elevation but said there is no knowing how low until I experiment. I have lived in Summit County and raised my children here; my children still live here. Moving was not an option. I started riding and skiing with portable oxygen. When 02 columns fail, so do I. I do have periodic episodes of extreme joint pain resulting from excessive stress/time at desk (10-hr days). However, I try to eliminate the pain by remaining active using oxygen when I need it. If I don’t use oxygen to sleep, I feel half dead the next day and it is difficult to wake up the next day. I worry about the long-term effects of the hypoxia, however I continue to monitor. I am hoping to see more research done in the area of high-altitude pulmonary hypertension.
Jennifer Wolfe is in her final semester of Nurse Practitioner school at Georgetown University. She was born and raised in Missouri and attended The University of Missouri where she graduated with a bachelor’s degree in psychology. After attending Mizzou she married her husband who was active duty in the US Navy. They traveled to many bases and had two boys before calling Denver their home in 2011. Jennifer received her BSN from Denver College of Nursing. Jennifer has spent 7 years as a nurse in the emergency department of several level II trauma centers before starting at Georgetown as a part of the Family Nurse Practitioner program. Jennifer enjoys spending her free time with her family and their three dogs.
There are three types of High Altitude Pulmonary Edema (HAPE) recognized in visitors and people living at high altitudes. These include classic HAPE (C-HAPE), which involves an individual that lives at low altitude traveling to high altitude. Re-entry HAPE (RE-HAPE) is seen in an individual that lives at high altitude who travels to low altitude and then returns to high altitude. And high-altitude resident pulmonary edema (HARPE) which occurs in an individual that lives at high altitude and does not change altitude (Ebert-Santos, Wiley). While these have been extensively studied and are subtypes that people are warned of, a fourth unexpected type of HAPE has been recently described by pediatric pulmonologist Santiago Ucros in Bogota, Columbia at the Universidad de los Andes. (Ucros)
Highlanders HAPE (HL-HAPE) occurs in people that live at high altitude who then travel to higher altitudes. Though most people who live at high altitudes for long periods of time assume they are immune to HAPE, the recognition of HL-HAPE shows this is not the case. One man had a run-in with HL-HAPE during his long-awaited trip to Mt. Kilimanjaro.
A resident of Summit County, Colorado, Jonathan Huffman set out to climb Mt. Kilimanjaro with his wife Katie when he was 37 years old. He is originally from Texas, but has been living in Breckenridge, Colorado, elevation 9,600 ft, for 15 years. In preparation for the climb, he spent the summer hiking multiple fourteen thousand foot peaks in Colorado, trail running at 9,000-12,000 ft, and mountain biking.
The elevation of Mt. Kilimanjaro is 19,341 feet and the summit generally takes each group anywhere from 5 to 9 days, depending on the route taken. In September, Jonathan and Katie traveled to Tanzania where they spent two days adjusting to jet lag and preparing for their climb. They had chosen to follow the Lemosho Route which is 42 miles long with an elevation gain of 16,000 to 17,000 feet.
On the first day, Jonathan and his party started at the Lemosho trailhead (7,742 feet) and hiked up 9,498 feet to the first camp. He noticed that his throat felt dry and he found himself having to clear it often. He attributed this symptom to the dusty environment.
On the second day, he felt as though his body was fighting the dust, which had found its way into his eyes, sinuses, and throat. He also felt extremely fatigued and stated that every action felt more difficult. Though he could tell his body was struggling to adapt, Jonathan continued to push forward with full force. He made it to the second camp at 11,500 feet.
“Day three, we went from 11,500 feet to 13,800 feet,” Jonathan recounts. “After we arrived to this camp, our guides offered to allow us to take a break then hike even higher. This was [an] optional acclimatization test … but I actually skipped it. I was so tired when I got to camp on this day, I decided to just nap in the tent until dinner time.”
On the fourth day, Jonathan’s group hiked up an overpass to Lava Tower located at 15,190 feet. This was also an altitude test, and he passed. He stated that this was the highest he had ever climbed, but that he was beginning to feel more like his normal self. The group stopped for lunch at the tower, but he did not have much of an appetite. He ate the food anyways at the insistence of the guides.
“Then after lunch, we descended down to Barranco Camp [from 15,190 feet to 13,044 feet] and this is where I realized I had HAPE.”
As they were nearing the camp, he felt fluid building in his lungs that was easy to cough up. By the evening, however, he felt as though he was drowning and was unable to lay down. While the guides encouraged him to immediately hike down, he did not want to hike in the dark. He spent the night propped up on duffle bags or sitting in a kitchen chair, with his oxygen reaching as low as 67% at one point.
In the morning, he received 30 minutes of oxygen treatment before beginning his 8-hour descent. His symptoms improved when he reached 6,500 feet. He was picked up in a rescue vehicle and received further treatment at a hospital in Moshi. While he made a full recovery, he stated that he still felt the effects of HAPE while exercising in Colorado at times, up to months after the experience. While Jonathan was only about 2 days away from the summit, he knew that turning back was the best choice. He plans to re-attempt the climb in a few years.
Jonathan’s story serves as an important reminder to those living at altitude that HAPE can affect anyone. Jonathan’s wife Katie along with everyone else in the group also experienced mild symptoms of altitude sickness including headaches. Research still needs to be conducted on the cause and prevention of this condition in all types. While this shouldn’t stop hikers and climbers from climbing mountains, they should be aware of the signs and symptoms of HAPE, when to seek treatment, and the best ways to prevent it from occurring.
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.
Health care providers and people who live at altitude often believe that living in the mountains protects from altitude related illness. And yes, there are many ways the body acclimatizes over days, weeks, months, and years, as addressed in previous blog entries. However, as a physician who has practiced in high altitude communities for over 20 years, my personal observation that we are still at risk for serious complications was reenforced by a recent publication by Dr. Santiago Ucrós at the Universidad de los Andes School of Medicine in Santa Fe de Bogotá, Colombia. His article, High altitude pulmonary edema in children: a systemic review, was published in the journal Pediatric Pulmonology in August 2022. He included 35 studies reporting 210 cases, ages 0-18 years, from 12 countries.
Consistent with our experience in Colorado, the most common ages were 6-10 years and second most common 11-15 years. I have not seen or read any reports of adults affected. Cases included two deaths, which I have also seen here.
I receive reports on any of my patients seen in urgent or emergency care. Accidents, avalanches, and suicide attempts are what we think of first needing emergency care in the mountains. However, the most common critical condition is Reentry HAPE. This is a form of pulmonary edema that can occur in children who are returning from a trip to lower altitude. Think visiting Grandma during school break. Dr. Ucrós’ review also confirms that all presentations of HAPE (classic, as in visitors, reentry, and HARPE, resident children with no history of recent travel) are more common in males by a 2.6 to 1 ratio. Analysis of time spent at lower altitude before the episode showed a range of 1.6 to 30 days with a mean of 11.3 days. Mean time between arrival and onset of symptoms for all types of HAPE was 16.7 hours. The minimum altitude change reported in a HAPE case was 520 meters (1700 feet), which is the difference between Frisco, CO (Summit County) and Kremmling, CO (Grand County, the next county over). A new form of HAPE in high altitude residents who travel to higher altitude was designated HL-HAPE in this review. A case report will be featured in an upcoming blog interview with a Summit County resident who traveled to Mt. Kilimanjaro.
As with all cases of HAPE, the victims develop a cough, sound congested as the fluid builds up in their lungs, have fatigue, exercise intolerance, with rapid onset over hours of exposure to altitude, usually above 8000 ft or 2500m. Oxygen saturations in this paper ranged from 55 to 79%. My patients have been as low at 39% in the emergency room. Children presenting earlier or with milder cases come to the office with oxygen saturations in the 80’s. An underlying infection such as a cold or influenza is nearly always present and considered a contributing factor. Everyone living or visiting altitude should have an inexpensive pulse oximeter which can measure oxygen on a finger. Access to oxygen and immediate treatment for values under 89 can be life-saving.
The recurrence rate for all types of HAPE is about 20%. Most children never have another episode, but some have multiple. Preventive measures include slower return to altitude, such as a night in Denver, acetazolamide prescription taken two days before and two days after, and using oxygen for 24-48 hours on arrival. Most families learn to anticipate, prevent, or treat early and don’t need to see a health care provider after the first episode.
On January 26, 2023 I met with Dr. Ucrós and other high altitude scientists including Dr. Christina Eichstaedt, genetics expert at the University of Heidelberg in Germany, Dr. Deborah Liptzen, pediatric pulmonologist, and Dr. Dunbar Ivy, pediatric cardiologist, both from the University of Colorado and Children’s Hospital of Colorado, and Jose Antonio Castro-Rodríguez MD, PhD from the Pontifica Universidad Católica in Santiago de Chile.
We discussed possible genetic susceptibility to HAPE and hypoxia in newborns at altitude with plans to conduct studies in Bogotá and Summit County, Colorado.
