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Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.See all posts »
Mountain & Wilderness Medicine World Congress Abstracts Part 3
As I noted in my first post about the Mountain & Wilderness Medicine World Congress, sponsored by the Wilderness Medical Society and the International Society for Mountain Medicine in Aviemore, Scotland from October 3-7, 2008, there were many excellent abstracts presented. The following is the third installment of some of the more interesting of these:
Chronic mountain sickness (CMS) is a syndrome in which person who reside for prolonged periods at high altitude develop symptoms and features that include a very high red blood cell count, enlargement of the right side of the heart (because of pressure in the pulmonary [lung] arterial system), and less efficiency of breathing. In “Hypoxic and hypercapnic responses in chronic mountain sickness,” Fabiola Leon-Velarde notes that residents living above 3000 m ( ft) in the Andes breathe less compared to acclimatized (to the altitude) newcomers, but more than sea-level natives at sea level. He further notes that persons with CMS who reside at altitude breathe like sea-level natives (e.g., they breathe less than non-CMS-stricken individuals at altitude). In a limited study, he looked at the effect of acetazolamide (Diamox), which is commonly used to prevent and/or treat high altitude illness in persons acutely ascending to altitude), on breathing in CMS persons. The preliminary observation is that acetazolamide may stimulate breathing in CMS persons.
Evan Lloyd and colleagues described, “A portable airway warming kit for use in the field.” In their abstract, they note that when hypothermia is encountered in the field, the first priority is to provide insulation to prevent further heat loss. After insulation has been achieved, the major heat loss is through breathing, where the body inhales cold dry air and exhales warm moist air. They further note that while there are many ways of producing airway warming, the problem is to make equipment that can be readily used in the field. They propose a method that utilizes absorption of carbon dioxide (produced by the body) by soda lime in a compact, lightweight package – in their suggested configuration, weighing only 300 grams. An additional benefit for their system is that it can reduce the flow rate for oxygen administration from 8 to 10 liters per minute to ½ to 1 liter per minute.
There is ongoing discussion and controversy about the benefits and ethics of training in an environment of lower (than is present at sea level) oxygen content to improve performance in athletic competition. In “Application of intermittent hypoxication exposure (IHE) to improve rock climbing performance,” Audry Birute Morrison and colleagues used a specific 15-day protocol to investigate whether or not there would be improvement in sea level climbing to exhaustion in two different climbing conditions – on a 15-degree overhanging route and on a vertical route. While the subject numbers for the study were too low to draw any firm statistical conclusion, the preliminary results were felt to suggest that IHE can improve endurance time specific to climbing, particularly on vertical routes.
More abstracts to follow…
photo of Cairngorm autumn courtesy of www.ski-injury.com
Tags: Wilderness Medical Society, WMS, International Society for Mountain Medicine, mountain medicine, Aviemore, World Congress, wilderness medicine, outdoor medicine, healthline
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