As a California native, I was unfamiliar with the impact high altitude had on the human body. I had only briefly learned about it in my exercise physiology course during my undergraduate studies. At best, I understood the difference between acclimation and acclimatization, and the advantages of living at high altitude for exercise performance. What I never really understood was how much all that information would mean to me when the next chapter in my life took me to Colorado.

In hindsight, I did everything against the book after moving to Colorado because I wanted to stay active and enjoy as much as I could before school started. I continued my daily workout routines, went whitewater rafting, and had a few drinks. More importantly, I was not hydrating adequately because I didn’t know you could drink straight from the tap. So… what happened? The end of my workout routines was met with dizziness and lightheadedness. On some occasions, I would notice my fingertips turn purple. My sleep would be interrupted by episodes of apnea. Though these symptoms did resolve eventually, they could have been prevented if I had followed a few simple rules.

As a student at Ebert Family Clinic in Frisco, CO at 9000′ alongside high altitude expert Dr. Christine Ebert-Santos, I had the opportunity to learn more about high altitude illness, interviewing Dr. Gustavo Zubieta-Calleja and his daughter Dr. Natalia Zubieta-Urioste from the High Altitude Pulmonary and Pathology Institute (IPPA) in La Paz, Bolivia. Dr. Zubieta has been practicing internal medicine and pulmonology at his father’s high altitude clinic since 1981. During our interview, we discussed their most recent publication Acute Mountain Sickness, High Altitude Pulmonary Edema, and High-Altitude Cerebral Edema: A view from the High Andes. When asked about what inspired him to follow his father’s footsteps, he replied, “My father created the first high altitude clinic in the world and that was a great inspiration to me. He did it with a visionary idea because at the time in 1970, nobody thought about putting a clinic like that out. I was born at home because my father was a physician and he preferred to deliver us. We [me and my siblings] were all delivered at home and then that home became the clinic in 1970. The clinic turned 50 this past year and our father also became our mentor at this clinic.”

The article addresses the two types of adaptation: genetic and physiologic. In his publication, he primarily addresses the physiologic mechanisms that must occur for one to adapt to the hypobaric environment that is high altitude. During my research, however, I found that Tibetans experienced the fastest phenotypically observable evolution in human history partially because their community has spent centuries living at that altitude. When I discussed my findings with Dr. Zubieta, he stated that much still needs to be done to determine if the Andean population has made similar genetic adaptations. He was optimistic about the studies to come as he strongly believes that all organisms must adapt if they want to survive and reproduce at high altitude. According to Dr. Zubieta, change is inevitable. He believes that the energy expenditure from the body’s initial response to the hypobaric environment is too costly forcing  the human body to adapt in a manner that will render it more effective in managing this energy expenditure via metabolism at the mitochondrial level.

We also discussed the different attitudes towards the use of acetazolamide, or Diamox. In the United States, acetazolamide is a diuretic commonly used to prevent the onset of acute mountain sickness. Dr. Ebert Santos highly recommends the use of acetazolamide to prevent acute mountain sickness while Dr. Zubieta and other providers reluctantly use it due to the risk of dehydration. A 125-milligram dose is adequate and unlikely to cause side effects, which Dr. Zubieta said can include fatigue, nausea, vomiting, abdominal pain, and diarrhea. (Most visitors to Colorado taking acetazolamide only experience tingling of the hands and feet and a flat taste to carbonated beverages.) Dr. Zubieta justifies his avoidance of acetazolamide as an “opportunity” to treat the patient’s underlying issues, stating that ascension to high altitude is a testament of one’s cardiovascular fitness and the use of acetazolamide compromises adaptation to high altitude. At the IPPA they have uncovered underlying conditions that explain their patients’ symptoms at altitude and resulted in better health upon returning to sea level.

 The Wilderness Medical Society has established a risk stratification for acute mountain sickness which further supports Dr. Zubieta’s infrequent use of acetazolamide. The society’s 2019 guidelines suggest that individuals with no history of altitude illness and ascending to an elevation no greater than 2,800 meters, and individuals who take more than two days to arrive at an altitude between 2,500 and 3,000 meters are considered low risk and the use of acetazolamide is not recommended. Instead, Dr. Zubieta recommends Ibuprofen and Acetaminophen for headache relief and oxygen in those with persistent symptoms of acute mountain sickness. He also emphasizes that oral hydration can be important in preventing high altitude illnesses.

Overall, Dr. Zubieta’s perspective on high altitude is fascinating. During my master’s program, I learned a systematic way to treat patients using guidelines or criteria backed by years of evidence that helps you, the provider, make an informed decision on a patient’s particular case. Dr. Zubieta reinforced the importance of treating each patient’s case individually to determine the underlying cause, rather than suggesting acetazolamide to everyone who doesn’t want to deal with acute mountain sickness. As for myself, seeing how physicians in other countries approach certain illnesses has definitely made me think twice about how to approach high altitude illness.

To learn more about Dr. Gustavo Zubieta and his clinic, you can visit his website at: https://altitudeclinic.com/

Born and raised in Northern Orange County of California, Michael Le is a second-year physician assistant student at the Red Rocks Community College Physician Assistant Program in Arvada, CO. Michael attended California State Polytechnic University Pomona otherwise known locally as Cal Poly Pomona where he earned his bachelor’s degree in Kinesiology. Shortly after, he worked as an EMT for Lifeline Ambulance, and physical therapy aide and post-anesthesia care unit technician at Fountain Valley Regional Hospital in Fountain Valley, CA. In his free time, Michael likes to cook and breed show rabbits.