A wedge-shaped pillow, with which the upper body is raised by 30 degrees, could be a solution to shortness of breath, headaches and nausea caused by ascending to high altitudes within a short time. In August 2016, researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) at the Italian Regina Margherita mountain hut in the Valais Alps investigated the mechanisms that trigger altitude sickness in the human body in 10 selected participants. In August 2017, a large number of mountain climbers will be examined to determine whether sleeping with a raised upper body is a simple and effective measure against the symptoms of acute altitude sickness. "Most mountain climbers use medication to prevent altitude sickness – but it has side effects," explains Ulrich Limper from the DLR Institute of Aerospace Medicine. "Elevation of the upper body has already been successful in patients in intensive care units and could also be effective in the case of oxygen deficiency at high altitudes."
When the human body receives too little oxygen, it automatically starts a relief programme: it increases the blood flow to increase the oxygen supply with the larger amount of blood. To this end, the arteries in the head dilate. "However, the drainage system does not seem to be designed for this, so the blood accumulates in the head." The result is familiar to mountain climbers from personal experience: headaches and nausea caused by the irritation of the brain structure.
Mountain climbers as test participants
The DLR study, which is scheduled to take place from 7 to 20 August 2017, is open to mountain climbers who ascend to the Regina Margherita mountain hut, Europe's highest-altitude building located 4554 metres above sea level. "We need participants that show symptoms of altitude sickness," says Limper. Potential volunteers are questioned and informed about the first signs of altitude sickness at both the valley station in Alagna as well as the Gnifetti hut at 3647 metres.
DLR researchers want to examine a total of 140 mountain climbers in their study. Half of the participants will spend the night at the Margherita Hut with an inflatable wedge-shaped pillow provided by DLR, and the other half will sleep in a horizontal position as usual. In order to keep the effort for the mountaineers as manageable as possible, their oxygen saturation and pulses are recorded using a finger only measuring device after the two overnight stays at the Gnifetti and Margherita huts. In addition, there are three short standardised questionnaires that mainly investigate the symptoms of altitude sickness, the quality of sleep and general well-being.
Water retention in the brain
"Our first study has shown that the brain is an important organ when it comes to seeking counter-measures for acute altitude sickness," says Limper. The 10 participants all presented altitude sickness symptoms after the rapid ascent, albeit to varying degrees. With subsequent MRI images, it was found that smaller swellings had formed in the brain. These occurred, among other things, because the inner layer of blood vessels had previously been damaged by oxygen deficiency and became more permeable to fluid.
Sleeping in an elevated position could counteract this. It had already proved its worth in the Middle Ages, when sleeping with your upper body raised was normal. Chronic lung diseases were frequent in the poorly ventilated rooms; the elevated position of the upper body gave relief. Similarly, the upper body of patients in hospital intensive care units. This reduces the volume of blood in the head and chest, and breathing is easier.
'Puffy face' and increased internal eye pressure
Astronauts face a similar problem to mountain climbers with their altitude sickness – albeit caused by other circumstances: Due to the lack of gravity, against which the heart usually has to work, an increased amount of blood is pumped to the head, hence the 'puffy face' (reddish and swollen) in the first days in space along with headaches, nausea and increased internal eye pressure. If people lived in habitats on other planets and do research, they would also be exposed to a special atmosphere with low pressure and oxygen. "The results of the high-altitude research studies could be helpful to counter the side effects of these conditions," says Limper.
Mountain climbers who wish to participate in the study at the Regina Margherita mountain hut in August 2017 can either register by email at firstname.lastname@example.org or register at the valley station in Alagna or the Gnifetti Hut with the DLR study supervisors.