Lessons from Everest Sherpas could help with intensive care


5th Sep, 2018 | Tourism Mail Crew


A research expedition to Mount Everest has shed light on the unique physiological basis of adaptations seen among the native Sherpa people who make them more suitable for life at high altitudes. This improved understanding, which is part of the new research, published in Experimental physiology, could help to improve the treatment of patients with diseases related to reduced blood and tissue oxygen levels.

Chomba Sherpa undergoing venous plethysmography on the expedition. Credit: Xtreme Everest

Sherpas are indigenous people who live at high altitudes and are known for their ability to live and climb in Himalayan heights where oxygen levels are lower. While genetic inheritance and natural selection in Sherpas are likely to have developed features that promote high altitude survival, the physiological basis behind their superior performance has been elusive. While the Lowlanders and other high-alpine populations (eg Andes and Ethiopians) are coping with the decreased levels of oxygen at high altitude by increasing the amount of oxygen-carrying cells (hemoglobin) in the body, the Sherpas do not. It always seemed a bit confusing and counterintuitive because how are you doing with less oxygen in the blood?

This question was studied by researchers from the Center for Altitude, Space and Extreme Environment Medicine at University College London on Xtreme Everest 2, a translational research program conducted at Mount Everest. The team conducted research comparing participants from two different populations: Sherpas and a high-naive Lowlander population. Baseline measurements were taken in London (50 m high) and Kathmandu (1300 m high) for participants in the Lowlander and Sherpa, respectively, and then repeated measurements were taken by the participants as they entered the base camp of Mount Everest (5300 m altitude). ascended. The individuals followed an identical ascent profile, ensuring that the physiological challenge, oxygen content, and temperature of the environment (which affects the narrowing of the blood vessels) were the same for all participants. Therefore, differences found between participants would be due to their individual physiology and not to variations in the magnitude or duration of exposure to low levels of high-concentration oxygen.

Sherpas has been found to be able to maintain a higher level of blood flow and oxygenation to working tissues as the amount of ambient oxygen decreases as it ascends to Mount Everest. In essence, this shows that Sherpas (compared to Lowlanders) are able to transport more oxygen around their bodies. These new findings could also explain how Sherpas thrive at altitude without increasing hemoglobin levels. High levels of hemoglobin make the blood thick and viscous and not only slow down the body's flow, but also increase the risk of side effects such as blood clots in the lungs. It is conceivable that by encouraging increased blood flow and high oxygen content oxygenation, sherpas are still able to provide enough oxygen to their tissues but minimize the risk of potentially deadly side effects.

The low oxygen concentrations at high altitude can simulate the reduced oxygen consumption of critically ill patients in the hospital. By understanding the physiology behind Sherpa's success in low-oxygen environments, we have been able to improve patient care by developing novel diagnostic and treatment strategies. Of course it is possible that physiological mechanisms may differ in height from those in hospital patients. However, studies of sick patients in the hospital are subject to ethical difficulties and, as patients may be ill for a variety of reasons (eg, heart attack or chest inflammation), they discuss which physiological responses are due to lack of oxygen. rather than the symptoms of the underlying disease or treatments that are applied is extremely difficult.

Dr. Edward Gilbert-Kawai, a co-author of the study, was delighted with the results of this study: "The mechanisms identified in this study, such as increased blood flow and oxygenation to work tissue, viably describe an alternative means of assisting oxygenation Uncovering such differences and mimicking them in people who are best adapted to reduced ambient oxygen can thus uncover new target pathways that are amenable to drug treatment in critically ill patients and could lead to new directions in intensive care. "