Extreme Everest 2017: Reflections From a Scientific Expedition

Extreme Everest 2017: Reflections From a Scientific ExpeditionOn March 30, we (members of Duke Anesthesiology) left Durham to participate in Extreme Everest 2017, a scientific expedition to the Everest base camp and Kala Patthar in the Himalayas. This had been organized by a British team, including Professors Monty Mythen and Mike Grocott, who had summited Mount Everest and performed numerous groundbreaking studies in 2007 and 2013. In the current expedition, we headed for Nepal for the second time, this time joined by a Duke Undersea and Hyperbaric Medicine (UHM) fellow, Dr. Chris Martin, and former Duke UHM fellow, Dr. Nicole Harlan, along with Dr. Joe Wiater and Fran Cullen, a financial advisor in Durham. The aim was to trek from Lukla to Everest base camp over 11 days, while measuring pulse oximetry continuously in a cohort of 14 individuals.

Why do this? What can be achieved from an observational study during the field expedition? The answer is that no one knows the lower limits of acceptability on blood oxygenation. While tens of thousands of individuals have trekked to Everest base camp without a problem, their oxygen saturation values have largely been unknown. Several studies have incorporated spot measurement of SpO2 but no published studies thus far have measured it continuously. In 2013, we obtained some data using wrist oximeters; the plan this year was to extend those studies.

Our team flew to Kathmandu, arriving on March 31. Among the 46 members of the group, several were doing research projects. These included an investigation of the microbiome and echocardiography at three different altitudes. Another investigation was looking for antigens that might explain the ubiquitous ‘Khumbu cough’ as due to inhalation of aerosolized yak dung particles. For our study, we signed up a number of the trekkers and obtained overnight baseline measurements. On April 3, we made our way to Kathmandu airport for the 40-minute flight in a Twin Otter aircraft to Lukla, altitude 9,317 feet. The Tenzing-Hillary airport at Lukla is reported to be the most dangerous airport in the world because its unique runway is positioned between two cliffs which leaves no room for error on landing. However, we landed safely and after gathering in a coffee shop for a brief refreshment, we headed up the mountain toward Monjo. Hiking in North Carolina can be challenging, but it is nothing like this. Unacclimatized as we initially were, dyspnea was a constant accompaniment. After several hours of hard trekking, we reached Monjo in the dark, and the next day to Namche (altitude 11,283ft), where we spent three days. Glancing periodically at our pulse oximeters revealed measurements that were consistently in the 70s. Apart from the shortness of breath, we felt fine and were able to carry on up the trail. Namche is a small town and would be the last ‘comfort stop’ on the way to base camp: there were coffee shops, lattes and just about anything you might need to buy for the remainder of the trip. The guest house where we stayed was owned by a man who was completely deaf due to meningitis as a child. However, he was a brilliant lip reader and an even more brilliant photographer. He plans to use proceeds from the sale of his photographs to fund a museum.

After our mandatory acclimatization, we headed up the trail toward Debouche (altitude 12,369 ft) and then Pheriche (14,010 ft), where we spent three nights, again to acclimatize. Pheriche is the site of the Himalayan Rescue Association, a bare bones facility but regularly and effectively staffed by doctors from around the world. Although most of us felt okay, medical problems started to occur. The first was one of our co-trekkers who abruptly lost consciousness while sitting outside a teahouse waiting for lunch. A couple of days later someone on another trek was visibly ataxic as he walked along the trail. The diagnosis: high altitude cerebral edema – HACE. Dr. Chris Imray, one of the British medical leaders, administered dexamethasone, walked with him to a helipad and escorted him back to Kathmandu by helicopter. Later, two of our group members would suffer HACE themselves. Fortunately, in all instances, dexamethasone and descent did the trick.

Extreme Everest 2017: Reflections From a Scientific Expedition

Gorak Shep (altitude 17,126 ft), the original base camp for the Hillary-Tenzing expedition in 1953, was our last stop. The day after our arrival there, most of the group trekked on to the current base camp at about the same altitude. The two of us, along with four other trekkers, including Chris Imray and Jeet Sherpa, hiked up Kala Patthar (altitude 18,519 ft). The prize on this mountain is a spectacular view of four peaks: Everest, Pumori, Lhotse and Nuptse. Although we didn’t quite make the summit due to incoming inclement weather, we did get the view and a backdrop for the Duke Anesthesiology banner. The climb nevertheless was tough, and my pulse oximeter was reading its lowest value of the trek: in the low 60s.

The next morning was the planned start of the descent. Before heading down, several of the trekkers set out at 5 a.m. to climb Kala Patthar. We and the British medical leaders had waited until their return before setting out. Unfortunately, as it turned out, one of our trekkers returned with a case of HACE. It would have been impossible to evacuate by helicopter as it was snowing, so she was given dexamethasone and allowed to sleep. The cure was miraculous: a few hours later she and her doctor, Dan Martin, zoomed past us on their way to the next stop at Loboche.

The downhill trek seemed uneventful until we were a few hours past Dingboche. As we walked through a small village, we were debating whether to stop for coffee when we spotted a few of our fellow trekkers. In the end, we decided to sit down with them to enjoy a few minutes of rest, but a few minutes later we heard someone yelling for help. Both of us, along with Aine Burns, a London nephrologist, and her daughter Brid, a medical student, rushed up the trail as fast as we were capable, where we found a man lying on the ground. The sherpa who had been accompanying him reported that he had not felt well earlier in the morning and had been advised to hike slowly. Abruptly, he had fallen down, unconscious. Fortunately, Nima (our Sherpa) had the medical kit with which we were able to check the man’s glucose to exclude hypoglycemia and then administer IV dexamethasone for presumed HACE. The stars had lined up for this man as a Nepali Army platoon was hiking through the village and was able to request a helicopter and carry the man up the hill for evacuation.

That night was spent at Tengboche, then we headed to Namche and then Lukla followed by the short hop back to Kathmandu.

What about our study? The data is being analyzed, but we had clearly observed that normal hikers trekked at altitude for long periods of time at SpO2 values, which if seen in any of our hospital patients would elicit panic. However, it was great to get back to normoxia where we could climb stairs and walk up hills with relative ease. We hope that the eventual publication, which might be entitled, “Oxygen saturation: How low can you go?” will elicit conversations as to alternative strategies for treating hypoxia in patients.

By Drs. Richard Moon and Eugene Moretti

Stacey HiltonExtreme Everest 2017: Reflections From a Scientific Expedition
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Duke Xtreme Everest 2 Recap

In 10 days the team trekked 40 miles and climbed 8,300 feet to the final Everest Base Camp altitude of 17,651 feet, where the barometric pressure is typically 400 mmHg (slightly higher than one half of the normal atmospheric pressure at sea level). Before commencing their descent a few of our team made the arduous climb to the top of Kala Pattar (altitude 18,192 ft). After 17 days at high altitude in the Khumbu Valley the Duke team returned to Kathmandu on April 21st to relax for a couple of days before flying home. The young lady who had developed high altitude cerebral edema was already there and had fully recovered.

In addition to participating in the studies organized by Xtreme Everest 2, the expedition provided a unique opportunity to observe firsthand the effects of chronic hypoxia and obtain nearly 3,500 hours of continuous blood oxygen saturation monitoring. This will provide new insight into the effects of decreases in oxygen saturation on performance under hypoxia.


Tamil Market -  Kathmandu

Tamil Market, Kathmandu

Chris KeithDuke Xtreme Everest 2 Recap
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Everest Team Reaches Base Camp

The Duke team was happy to see former Duke faculty member Dr. Monty Mythen, chair of Anaesthesia at University College London.  He is shown here with his daughter Charlotte at the Namche Bazaar High Altitude Lab, altitude 3,440 meters, 11,286 ft. (Charlotte was born at Duke Hospital).  The team reached Everest Base Camp (altitude 5,364 meters, 17,598 ft) on April 10, where the observations were made of altitude sickness scores and oxygen saturation.  On the way down toward Dingboche one of the other trekking team members developed high altitude cerebral edema (HACE) and had to be evacuated by helicopter.  This cut short Dr. Moon’s trek, as he accompanied her to the medical facility in Kathmandu.

Dr. Monty Mythen, Chair of Anesthesia UCL and Daughter Charlotte, born at Duke

Dr. Monty Mythen, Chair of Anesthesia UCL and Daughter Charlotte, born at Duke

Everest Base Camp-Drs. Chris Young, Gene Moretti, Richard Moon. Peter Moon on Far Right

Everest Base Camp-Drs. Chris Young, Gene Moretti, Richard Moon. Peter Moon on Far Right

Everest Base Camp

Everest Base Camp

Dr. Gene Moretti Cracks a Joke during Breakfast at Everest Base Camp

Dr. Gene Moretti Cracks a Joke during Breakfast at Everest Base Camp

Dr. Chris Young Enters AMS Score on Tablet Computer

Dr. Chris Young Enters AMS Score on Tablet Computer

HACE Victim Exiting Helicopter Lukla

HACE Victim Exiting Helicopter Lukla

Chris KeithEverest Team Reaches Base Camp
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Update from Pheriche

Update from Pheriche Nepal

Xtreme Everest 2 trekkers have passed the 4000 meter mark and are now in Pheriche at 4270 meters (14,009 feet) in altitude. We are now on a scheduled 2 day “rest” as part of the acclimatization protocol.

We spent 3 days in Namche where we were able to catch up with Nelson Diamond from Duke (3rd year medical student) who is working at the Xtreme Everest lab there under the able guidance of Monty Mythen.

The rest interval after the tough walk up to Namche was most welcome. Hot showers, short hikes, and visits to the coffee shop in town (real Illy coffee!) helped with the acclimitization process. The views of Everest from just beside the lodge were spectacular!

Baseline oxygen saturations improved to high 80s – low90s for most of the trekkers and everyone was rested for the next leg of the journey.

Namche to Deboche was a beautiful trek with Everest in view ahead of us throughout the day and  Ama Dablam (or the upside down ice cream cone, as some of the trekkers refer to it) our constant companion on the right hand side.

Incredibly, even the fittest trekkers demonstrated saturations in the low 70s during some of the more strenuous parts of the hike.

Deboche to Pheriche was again a spectacular day with incredible views and beautiful weather. Other than the afternoon of rain on the hike from Lukla to Monjo, it has been beautiful, sunny weather. As we gain altitude the rhododendron forest has given way to pine and now scattered shrub junipers are the only vegetation we see. The Himalayan Rescue Association is based here in Pheriche, where they provide medical care for trekkers and the local population. Fortunately, none of the XE2 trekkers have required their services.

So, it’s another day of rest (an “easy” 400 meter acclimatization hike tomorrow morning) before the final 3 day push on to Base Camp.

See the XE2 blog for additional updates and tweets:






Chris KeithUpdate from Pheriche
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Update from Namche

The team spent a couple of nights at the Summit Hotel in Kathmandu, where we were briefed on the journey by our trek leader. In the photo below are, from the left: Peter Moon Anna Grodecki (former Duke Fellow), Richard Moon, Petrus Fourie, Chris Young, Hementa Maharaj, Mike Teamby, Ken Stapleton, Gene Moretti, Rob Wymer (trek leader). We all volunteered to be study participants in an experiment on nitrate absorption.  We survived the low nitrate diet and the 3:30 am blood draw and headed for the airport for the short flight to Lukla, said to be the most dangerous in the world. The landing on the short uphill strip, which ends in a sheer cliff, went as planned. After unloading our gear we headed for our hotel in Monjo. Chris Young’s study of continuous recording of pulse oximetry on the way to and from Everest Base Camp is a first. It was daunting to watch our oxygen saturation (which was around 85% in Lukla) decrease into the 70’s as soon as we started to walk. It didn’t take long until we adjusted our walking speed to a slower rate. It took around 6 hours to reach Monjo. The Boston Marathon’s Heartbreak Hill is nothing compared to the slope leading up toward Monjo, especially with an oxygen saturation less than 80%. After dinner we headed to bed and the next day started a 2000 foot climb to Namche, the old Sherpa capital. Namche’s altitude is 11,500 ft, has a population of around 2000 and hosts the Xtreme Everest Lab, headed by Dr. Monty Mythen, Anaesthesia Chairman at University College London. We are now acclimatizing in Namche for two days in preparation for the next uphill step toward Base Camp.

Namche Day 2 013_NEW

Left to right Anna Grodecki, Peter Moon, Nelson Diamond (Duke medical student), Richard Moon, Chris Young and Gene Moretti. In the background can be seen Everest (2nd peak from the left), Lhotse and Amadablam.


Namche Day 2 022_NEW

Chris Young is shown with the MobileDemand tablet used for downloading the pulse oximetry data collected on the 9 volunteers.


Chris KeithUpdate from Namche
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Duke Everest Trekkers Gather


March 29

Despite the vagaries of air travel, all trekkers managed to converge on the Summit Hotel in preparation for the journey to Base Camp.

Everest Team takes part in traditional Buddhist blessing

Peter Moon, Anna Grodecki (former Duke Hyperbaric Fellow) Richard Moon, Gene Moretti, and Chris Young took part in a traditional Buddhist blessing prior to making final preparations for the trek


Chris KeithDuke Everest Trekkers Gather
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