Members of the Caudwell Xtreme Everest expedition, testing human adaptation to hypoxia on the roof of the world, write a diary blog for Nature from 30 March, 2007.
Here at Everest Base Camp in Nepal the science continues to flourish. It is a strange environment in which to work but after some time you do get used to it. We are living on glacial moraine created by the mighty Khumbu glacier. At night as we try to sleep the only sounds that can be heard are that of the ice creaking and snapping below us and avalanches crashing down the giant rock faces above us. In front of our camp lies the Khumbu ice fall, the tumbling face of the glacier that drains from the Westen Cwm, a snow bowl created in the rock horseshoe of Everest, Lhotse and Nuptse. In the morning it is somewhere between -5 and -10 oC, by lunchtime inside the laboratories it can reach nearly 20 oC. These conditions are very challenging for both investigators and subjects.
We have basically built ourselves a small village up here in the mountains. About forty little tents surround the central hub of the Caudwell Xtreme Everest project. We have laboratories constructed from shelters used in the arctic by the military. These laboratories are where we carry out our work into how humans effectively adapt to the hypoxia of high altitude. There are three cardiopulmonary exercise (CPX) systems in continuous use, on which we are cycling daily whilst measuring oxygen consumption and carbon dioxide production on a breath-by-breath basis. Most exercise laboratories at sea level have only one such system in place; to have three running simultaneously at 5,300m above sea level has been no small feat.
We are also taking blood from one another, centrifuging it to produce plasma, then storing it in liquid nitrogen ready for transportation back to the UK. By the time the project is complete we will have almost 15,000 individual plasma samples to bring home and analyse. To provide enough cold storage facility for our laboratories in Nepal we have already used 100 litres of liquid nitrogen. A dedicated team of porters ensures a regular supply to top up the liquid nitrogen dewars posted at each of the laboratories.
To power all this research we need an uninterruptible electricity supply, which is easier said than done up here. Our logistics team have engineered a faultless power system which any professional electrician would be proud of. Generators provide electricity in the day with a battery back up system for the evenings and in case of generator failure. Unfortunately to power our labs by solar panels we would have to carpet most of base camp with panels which, as you can imagine, would be highly impractical.
We also have medical facilities comparable to that found in any UK hospital. Our staff includes general practitioners, nurses, anaesthetists, physicians, intensivists and surgeons. Not only can we offer our trekkers a daily clinic for ailments they have picked up along their journey but we have the capability to resuscitate patients following cardiac arrest or major trauma, perform minor surgery and artificially ventilate if such unfortunate circumstances arose.
The first of our groups of trekkers has arrived at base camp in good spirit and testing of them has begun. Many more groups are strung out along the valley, slowly making their way here, to base camp.
Next week I’ll begin to explain some specific details about the different studies which form the Caudwell Xtreme Everest project.