tailieunhanh - Báo cáo khoa học: "High-altitude physiology and pathophysiology: implications and relevance for intensive care medicine"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: High-altitude physiology and pathophysiology: implications and relevance for intensive care medicine. | Available online http content 11 1 203 Review High-altitude physiology and pathophysiology implications and relevance for intensive care medicine Michael Grocott Hugh Montgomery and Andre Vercueil Centre for Altitude Space and Extreme Environment Medicine CASE Medicine UCL Institute of Human Health and Performance Ground Floor Charterhouse Building UCL Archway Campus Highgate Hill London N19 5LW UK Corresponding author Michael Grocott Published 1 February 2007 This article is online at http content 11 1 203 2007 BioMed Central Ltd Critical Care 2007 11 203 doi cc5142 Abstract Cellular hypoxia is a fundamental mechanism of injury in the critically ill. The study of human responses to hypoxia occurring as a consequence of hypobaria defines the fields of high-altitude medicine and physiology. A new paradigm suggests that the physiological and pathophysiological responses to extreme environmental challenges for example hypobaric hypoxia hyperbaria microgravity cold heat may be similar to responses seen in critical illness. The present review explores the idea that human responses to the hypoxia of high altitude may be used as a means of exploring elements of the pathophysiology of critical illness. Introduction Hypoxaemia is a common consequence of critical illness. Hypoxaemia in critical illness may be caused by hypoventilation ventilation perfusion mismatch right-to-left shunting or limitation of diffusion across the alveolar-capillary membrane. Hypoxaemia my also occur as a result of breathing a low fractional inspired oxygen tension for example at high altitude. Tissue hypoxia reduced cellular or mitochondrial oxygen availability may arise as a consequence of hypoxaemia or as a result of reduced oxygen delivery due to decreased cardiac output or decreased red-cell concentration anaemia . Tissue hypoxia may also occur in association with the systemic inflammatory response syndrome. This may be due to decreased .