Influence of Moderate Altitude Residence on Arterial Oxygen Saturation at Higher Altitudes

摘要

Mountainous terrain provides sanctuary for hostile forces as seen in Central and West Asia, the Balkans, and South America. This harsh environment lessens U.S. military technological superiority by limiting use of air support and crew-served combat vehicles. This places the burden of combat on dismounted warfighters. Objective Force Warrior (OFW) emphasizes the rapid deployment and mobility of troops to conduct operations for sustained periods without relief. However, rapid deployment of unacclimatized troops to high mountainous environments causes debilitating effects on fighting capabilities and Force health. Environmental illnesses are a significant portion of the non-battle injuries sustained by U.S. military forces. For example, during a major combat operation in Afghanistan, 12% of medevacs and hospital admissions were due to severe Acute Mountain Sickness. Available guidance for minimizing adverse effects of high altitude is based on worst-case scenarios that assume the personnel have no degree of altitude acclimatization. Many military bases are located at altitudes at which personnel will develop some magnitude of altitude acclimatization (>1,500 m). However, the magnitude of altitude acclimatization developed in lowlanders residing at moderate altitudes has not been well documented. This study compared the distribution of arterial oxygen saturation and subjective symptoms to hypoxia in moderate altitude residents and low altitude residents following rapid ascent to 4,056 m (pressure altitude). This work will add to a database that will contribute to the development of models that should provide operational commanders with medical planning capability for high mountainous operations, resulting in decreased altitude illness, and reduced manpower and logistical and medical support requirements.