Wilderness medicine at high altitude: recent developments in the field

Abstract

Travel to high altitude is increasingly popular. With this comes an increased incidence of high-altitude illness and therefore an increased need to improve our strategies to prevent and accurately diagnose these. In this review, we provide a summary of recent advances of relevance to practitioners who may be advising travelers to altitude. Although the Lake Louise Score is now widely used as a diagnostic tool for acute mountain sickness (AMS), increasing evidence questions the validity of doing so, and of considering AMS as a single condition. Biomarkers, such as brain natriuretic peptide, are likely correlating with pulmonary artery systolic pressure, thus potential markers of the development of altitude illness. Established drug treatments include acetazolamide, nifedipine, and dexamethasone. Drugs with a potential to reduce the risk of developing AMS include nitrate supplements, propagators of nitric oxide, and supplemental iron. The role of exercise in the development of altitude illness remains hotly debated, and it appears that the intensity of exercise is more important than the exercise itself. Finally, despite copious studies demonstrating the value of preacclimatization in reducing the risk of altitude illness and improving performance, an optimal protocol to preacclimatize an individual remains elusive.

Effects of Dietary Nitrate Supplementation on Physiological Responses, Cognitive Function, and Exercise Performance at Moderate and Very-High Simulated Altitude

“…The effects of ${\text{NO}}_3^{-}$ supplementation on key physiological or functional (e.g., time required to walk a given distance) parameters during this type of activity are presently unclear. However, further study is warranted given a relatively small number of people ascending to altitude are trained athletes conducting high-intensity exercise, yet thousands of individuals undertake altitude hiking and mountaineering each year (Shah et al, 2015). …”

The Role of Oxidative Stress in the Development of Acute Mountain Sicknessand Possible Methods of Prevention

“…If we take this statement to be completely accurate, this would allow development of appropriate methods of preventing AMS instead of the current practice that is limited to emergency measures applied upon AMS occurrence. antyoksydacyjnych przez odpowiednio umiarkowany trening wydolnościowy [10,25,37,38] przed wyjazdem w góry. Dodatkowo, w okresie przed wyjazdem należałoby rozpocząć suplementację witaminami antyoksydacyjnym (A, C, E) [39,40] oraz kwasem lipo no wym [36].…”

“…tised before going to the mountains [10,25,37,38]. In addition, in the pre-departure period, supplementation should start with antioxidant vitamins (A, C, E) [39,40] and lipoic acid [36].…”

Evaluation of renal excretion and pharmacokinetics of furosemide in rats after acute exposure to high altitude at 4300 m

“…High altitude medicine is an emerging subspecialty that belongs to the category of environmental medicine and medical biology. At the same time, it has crosscutting relevance to basic medicine, medical psychology and social sciences: from sports medicine and the aerospace industry to urban and rural communities living at high altitude (Shah et al, ). After acute or chronic exposure to high altitude, the pharmacokinetics of conventional drugs such as carbonic anhydrase inhibitors (acetazolamide), antipyretic analgesics (acetylsalicylic acid), corticosteroids (prednisolone), diuretics (furosemide), antibacterial (sulfamethoxazole) and antibiotics (gentamicin) etc., have certified variations (Arancibia et al, , ; Li, Liu, Li, Yuan, & Zhu, ; Vij, Kishore, & Dey, ), in accordance with our previous study of antiarrhythmic drugs (propranolol and metoprolol) (Zhang et al, ).…”