Life at 7000M (PART III)
Editor's Note - Most of our readers know Nancy Hansen as an ACC Ambassador, an accomplished mountaineer and the person closest to completing what is perhaps the greatest tick list in all of climbing – The 50 Classic Climbs of North America.
Here, Nancy and her partner Ralf Dujmovits, go inside for science – into a “hypoxia chamber” in Cologne, Germany - to be guinea pigs for a study on the positive benefits of extreme hypoxia on human beings.
Note that this is not a tacked-on medical test while on an expedition or acclimatizing for a big mountain, this is two climbers volunteering for a month of severely limited oxygen in the hopes of benefiting medicine and helping others.
This is the final chapter of her 3 part series.
Hovering the safety line
When we went to the German Aerospace Center for initial baseline measurements in January, it was obvious to me that my partner, Ralf Dujmovits, was the main subject of interest in the medical study. He had the high altitude experience, and I, with worlds less, was the unknown. It seemed to me that everyone assumed I would not make it to the end of the study. In all honesty, I assumed the same thing.
When the five-week, high-altitude / low oxygen – heart muscle repair study began in earnest in mid-May, attitudes changed. Ralf was a boring subject. His body changed and adapted to the higher altitudes, but quickly, easily, and without drama. It seems that having climbed 18 times to the top of 8,000 m peaks and countless other high summits was in his favour.
The goal was for us to spend the last two weeks balancing certain blood oxygen thresholds and heart pressure measurements on a defined line. It was estimated that these numbers would occur at 7,100 m, or 8% oxygen. As it turned out, I was constantly hovering on the safety line at 6,700 m (8.5%), so that was the altitude at which we spent most of our time.
This is the altitude profile that became our reality over the five weeks of the study. File created by Dr. Ulrich Limper.
Altitude Guinea Pigs
I’ve never been above 6,700 m, and I always considered myself a poor acclimatizer. Even though we had pre-acclimatized in the Alps, I already felt crappy on the first night in the lab at 3,500 m! From the very beginning, my body reacted quite dramatically and the scientists soon turned their attention on me. Over the five weeks, I had many, many more examinations, blood draws (~50!) and echocardiographs than Ralf. We started making jokes about him - that extra person in the room who still needed to be fed and talked to sometimes.
In all seriousness, the scientists seemed to be truly happy with the situation. I became the subject of interest; the one whose critical values were carefully balanced on the line they had purposefully drawn. Ralf became the control subject. And although we were subjects in a sealed laboratory, we felt very much a part of the team and the decision-making.
Starting on Skis
We started the study in early May by going on a week-long, high ski tour along the crest of the Alps, with Cervinia, Italy on one side, and Zermatt, Switzerland on the other. One night, we could see the city lights of Milan, fashion centre of Italy, twinkling in the distance.
At the Margherita Hut. At 4,554 metres, it is the highest building in Europe! Photo by Ralf Dujmovits.
After enjoying five nights of warm comfort and amazing food in the full-service Italian and Swiss huts up to 3,647 m, we moved up to the Margherita Hut, on top of one of the Monte Rosa summits at 4,554 m! This insanely placed hut is no small bivi shelter, as one might expect. The first hut was built in 1893, and the current 70-bed facility opened in 1980. In summer, you can purchase full breakfasts, dinners, cakes, beer and wine, just like in most other European huts. In winter months, as when we were there, one must shiver in the winter room, share the single teaspoon and fork that are provided for up to 12 guests, and stare at the chimney pipe that used to have a warm wood-burning stove attached to it. Still, we enjoyed the night immensely. We stood outside for two hours in the evening sun, watching the clouds dance over the 4,000-metre peaks below us, including the ever-famous Matterhorn.
At the Margherita Hut. At 4,554 metres, it is the highest building in Europe! Photo by Ralf Dujmovits.
Hypoxia on the heart, body and mind
On May 15, we moved into our windowless, but spacious laboratory in Cologne, Germany, where they spent the next five weeks pumping in copious amounts of nitrogen in order to reduce the oxygen. In this first-ever medical study of its kind, the scientists hope to prove that, as when it is developing in low oxygen conditions in the womb, human heart tissue can regenerate itself under hypoxic conditions. Even though there is still a mountain of data to be analyzed, the scientists are extremely pleased with the early results and the simple fact that the study could actually be completed.
For Ralf and I, it was fascinating to observe the clinical changes in our bodies as the study went on. Here are a few facts:
- My pulmonary tension was more than double what is considered “high pulmonary tension” in a normal illness of this sort. This means that the blood was getting backed up in the right side of my heart and pulmonary artery, creating big pressure. Ralf had slight pulmonary tension.
- In both Ralf and I, our hearts got a bit smaller and the walls got thicker over the study. The big pressure in my right ventricle deformed the left ventricle.
- My brain developed a few “white lesions”. The veins in both of our brains became swollen, but especially in Ralf’s.
- I slept with a heart rate that was often over 80. Ralf’s was much lower, although in the last week of the study, he had thousands of extra-systolic beats per night, and at one point, they registered a 6.5-second break between two heartbeats!
- My blood oxygen saturation was sometimes in the low 50s. Ralf’s was rarely below 70. I got excited when mine went up to 70! Most people who are reading this will have an O2 saturation of between 95 and 100%.
- My partial pressure oxygen was usually right around 35 Hg. Ralf’s was usually over 40, although his started to decrease in the last week. Yours is likely between 75 and 100 Hg. This was probably the number one critical value that the doctors kept an eye on.
- My iron stores are completely gone. Ralf still has lots.
There are dozens more numbers and images, but those are some of the main points.
This was a low point in the study for my new friend called "pulmonary tension". My ability to walk and ride the bike actually started to improve after this day, as my heart and lungs slowly began to adjust to the altitude. Video by Ralf Dujmovits.
The miracle of our bodies is that less than 48 hours after re-oxygenation, most of these values returned to normal! It was shocking to watch the last echocardiograph and see our hearts behaving as if nothing had ever happened. Of course, a few of the changes will take a bit longer to return to normal, but we expect that at our first follow-up visit at the end of July, our brains, hearts and blood values will all be as they were before the study began.
Here are side-by-side MRI movies of my heart. The left one was taken on May 16, at the beginning of the study (although we were already acclimatized to 4,500 m). The right one was taken on June 8; 24 days into the study. At this point, we had spent eight days between 6,700 m and 7,100 m. After this MRI was taken, we spent an additional ten days at 6,700 m. You can see that my heart is already smaller, shaped differently, and the walls are thicker.
One thing that surprised all of us, Ralf and I included, was that we had absolutely no cognitive deterioration over the five weeks. We performed one of two cognitive tests every day, one of them developed by NASA and used by the astronauts. Anecdotally, we know that some mountaineers have had cognitive issues at altitude (i.e. poor decision making, slow reaction times, inability to think clearly, etc.). Perhaps we were not high enough, or perhaps there are other external factors that contribute to cognitive issues. Whatever the case, it was an interesting non-result from the study.
A surprise from space
It isn’t everyday you get a phone call from outer space! Alexander Gerst, the soon-to-be-first German Space Commander, called us up shortly after arriving at the International Space Station to find out what we were up to!
Another surprise involving NASA and astronauts was when Astro Alex, the soon-to-be-first German Space Commander, phoned us in the lab… FROM SPACE. He is from Cologne and obviously did a lot of his training at the German Aerospace Center. The three of us talked for almost 15 minutes. He asked us what it was like in the lab, and we asked him what it was like in space. Fun!'
Returning to big open air
It was a momentous occasion to leave our windowless laboratory without a low-content-oxygen mask, after 36 days! We immensely enjoyed working with a great team at the German Aerospace Center, and we hope they get good results from our study. Photo by Felix Oprean, DLR.
We took 48 hours to “re-oxygenate” in the lab, i.e. to return to 21% oxygen. A huge part of the study team gathered to send us off, and Ralf and I both felt quite emotional. We’d trusted our lives to and had grown close to this wonderful group of people, and, believe it or not, we were sad to be leaving.
The first thing I noticed about being outside after five weeks is that outside is BIG! And busy too. With lots of oxygen. It tastes good.
Hiking in the German Alps. Photo by Alina Erdkönig.