Health Considerations at Elevated Altitude

Each year, planning the Annual Scientific Meeting (ASM) employs a multifaceted team approach in order to provide an intellectually stimulating educational experience. There are many considerations involved in the decision-making processes used to choose the various components of a wonderful meeting.  From dynamic speakers to meeting educational requirements, and from exciting locations, many work diligently to provide our society with a valuable experience.

Beautiful Denver, Colorado, the ‘mile high city’, is the site for the 2026 ASM. I realized how little I know about the unique circumstances that living, working, and playing at elevation pose.  

UHMS is an organization devoted to maintaining the highest level of safety possible. One finds that the definition of safety varies depending on the industry construct, and many experts agree that parameters used to determine safety are often confusing (Safety Science, February 2024).  We work in a highly specialized field, with specific considerations to what is deemed ‘safe.’  Safety, for our patients, colleagues, organizations, and ourselves, is paramount.

Keeping safety in mind while visiting Denver for the ASM, here’s a brief refresher of exposure to high altitude, and its possible effects. Even if you’re not physically exerting yourself while visiting an area with increased altitude, you may feel the effects of hypobaric hypoxia. Headache, dizziness, shortness of breath, altered mental status, and cardiovascular symptoms might affect those not conditioned to elevation. Anyone with pre-existing health conditions, such as heart failure and pulmonary disease, is likely at greater risk for illness with increased elevation.

As altitude increases, air pressure decreases, resulting in a significantly lower partial pressure of oxygen (O2), even though the percentage of O2 remains the same as at sea level, approximately 21%. This reduced atmospheric pressure causes fewer O2 molecules to be available with each breath, resulting in hypoxia. Although the US military typically considers 8,000 feet (2,438 meters) as a guideline, altitude physiologists use 5,000 feet (1,524 meters) as a marker, as it is at that elevation where we show signs of increased work to breathe. Denver’s elevation is greater than 5200 feet, (1609 meters).

Individuals engaging in sports such as skiing, snowboarding, and mountaineering should be aware of the potential health risks associated with exertion at high altitudes.

According to the NIH National Library of Medicine, Acute Mountain Sickness, aka, Altitude Sickness/Illness, is much milder and more common than High Altitude Pulmonary Edema (HAPE), and High-Altitude Cerebral Edema (HACE), which require emergency treatment. Hyperbaric treatment rapidly reverses catastrophic effects, which include fluid-filled lungs, brain swelling, coma, and, quite possibly, death. HAPE causes accumulation of fluid in the lungs. HACE causes rapid development of brain swelling. Both are immediately life-threatening.

Rapid, immediate descent from altitude is required, but it is often not possible or does not have a significant effect. Portable chambers provide crucial hyperbaric treatment that can simulate a descent of up to 7,000 feet (2,134 meters). This treatment is meant to stabilize the patient while awaiting evacuation. These chambers are lightweight, can be used in remote locations, and do not need electrical power for operation.

Treatment in a fixed chamber where 100% O₂ is delivered under a prescribed pressure and time rapidly relieves symptoms. Hyperbaric O₂ treatment plans, combined with other necessary medical care, can save lives. Critical care of the patient also includes pharmacological intervention. Depending on the severity of the illness, the treatment plan may include diuretics, corticosteroids, non-steroidal anti-inflammatory medications, antiseizure medications, and calcium channel blockers. This is an example of treatment options; other inhibitor and agonist drugs are also used. Clinically administered hyperbaric oxygen treatment is considered curative for high-altitude illnesses.

The human desire to explore unknown environments poses unique physiological challenges. Whether we are scaling Mount Everest, diving the Great Barrier Reef, or soaring into space, scientists investigate methods to protect us. Preventing illness is ideal, but having corrective and curative treatments when needed enables us to push forward into new frontiers. Be safe in your travels and enjoy what life has to offer.

 References

Basnyat, B., Murdoch, D.R. (2003). High-altitude Illness. The Lancet.

De Florio, F. (2011). Airworthiness. Science Direct, Chapter 2, 3-4. Chapter 2 - Airworthiness, https://doi.org/10.1016/B978-0-08-096802-5.10002-9

Houston, C.S. (1992). The Gamow Bag in the Treatment of Acute Mountain Sickness. The Western Journal of Medicine.

Imray, C., Wright, A., Subudhi, A., Roach, R. (2010). Acute Mountain Sickness: Pathophysiology, Prevention, and Treatment. Progress in Cardiovascular Diseases.

 Karanikas, N., & Zerguine, H. (2024). Are the new safety paradigms (only) about safety and sufficient to ensure it? An overview and critical commentary. Safety Science, Volume 170, https://doi.org/10.1016/j.ssci.2023.106367.

Prince TS, Thurman J, Huebner K. Acute Mountain Sickness. [Updated 2023 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430716

Savioli G, Ceresa IF, Gori G, Fumoso F, Gri N, Floris V, Varesi A, Martuscelli E, Marchisio S, Longhitano Y, Ricevuti G, Esposito C, Caironi G, Giardini G, Zanza C. Pathophysiology and Therapy of High-Altitude Sickness: Practical Approach in Emergency and Critical Care. J Clin Med. 2022 Jul 6;11(14):3937. doi:10.3390/jcm11143937. PMID: 35887706; PMCID: PMC9325098.

University of Colorado Denver. (2011, March 26). Living at high altitude reduces risk of dying from heart disease: Low oxygen may spur genes to create blood vessels. ScienceDaily. www.sciencedaily.com/releases/2011/03/110325151643.htm