The Hen or the Egg: Impaired Alveolar Oxygen Diffusion and Acute High-altitude Illness?

International Journal of Molecular Sciences

Franziska Macholz¹  Daniel Dankl¹  MarcM. Berger¹  Christoph Dehnert²  Heimo Mairbäurl³  Mahdi Sareban⁴ 

[1] Department of Anesthesiology, Perioperative and General Critical Care Medicine, University Hospital Salzburg, 5020 Salzburg, Austria;Medbase Checkup Center, 8400 Zürich, Switzerland;Translational Lung Research Center (TLRC), part of the German Center for Lung Research (DZL), University of Heidelberg, 69120 Heidelberg, Germany;University Institute of Sports Medicine, Prevention and Rehabilitation, and Research Institute of Molecular Sports Medicine and Rehabilitation, Paracelsus Medical University, 5020 Salzburg, Austria;

关键词: high-altitude pulmonary edema;    acute mountain sickness;    oxygen diffusion limitation;   

DOI  :  10.3390/ijms20174105

来源: DOAJ

【 摘 要 】

Individuals ascending rapidly to altitudes >2500 m may develop symptoms of acute mountain sickness (AMS) within a few hours of arrival and/or high-altitude pulmonary edema (HAPE), which occurs typically during the first three days after reaching altitudes above 3000−3500 m. Both diseases have distinct pathologies, but both present with a pronounced decrease in oxygen saturation of hemoglobin in arterial blood (SO₂). This raises the question of mechanisms impairing the diffusion of oxygen (O₂) across the alveolar wall and whether the higher degree of hypoxemia is in causal relationship with developing the respective symptoms. In an attempt to answer these questions this article will review factors affecting alveolar gas diffusion, such as alveolar ventilation, the alveolar-to-arterial O₂-gradient, and balance between filtration of fluid into the alveolar space and its clearance, and relate them to the respective disease. The resultant analysis reveals that in both AMS and HAPE the main pathophysiologic mechanisms are activated before aggravated decrease in SO₂ occurs, indicating that impaired alveolar epithelial function and the resultant diffusion limitation for oxygen may rather be a consequence, not the primary cause, of these altitude-related illnesses.

【 授权许可】

Unknown