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High-altitude pulmonary edema (HAPE) (''HAPO'' spelled oedema in British English) is a life-threatening form of non-cardiogenic pulmonary edema (fluid accumulation in the lungs) that occurs in otherwise healthy mountaineers at altitudes typically above . However, cases have also been reported at lower altitudes (between in highly vulnerable subjects), though what makes some people susceptible to HAPE is currently unknown. HAPE remains the major cause of death related to high-altitude exposure, with a high mortality rate in the absence of adequate emergency treatment. ==Signs and symptoms== Physiological and symptomatic changes often vary according to the altitude involved.〔(【引用サイトリンク】publisher=Altitude.org )〕 The Lake Louise Consensus Definition for High-Altitude Pulmonary Edema has set widely used criteria for defining HAPE symptoms: Symptoms: at least two of: * Difficulty in breathing (dyspnea) at rest * Cough * Weakness or decreased exercise performance * Chest tightness or congestion Signs: at least two of: * Crackles or wheezing (while breathing) in at least one lung field * Central cyanosis (blue skin color) * Tachypnea (rapid shallow breathing) * Tachycardia (rapid heart rate) The initial cause of HAPE is a shortage of oxygen caused by the lower air pressure at high altitudes.〔 The mechanisms by which this oxygen shortage causes HAPE are poorly understood, but two processes are believed to be important: # Increased pulmonary arterial and capillary pressures (pulmonary hypertension) secondary to hypoxic pulmonary vasoconstriction. # An idiopathic non-inflammatory increase in the permeability of the vascular endothelium.〔 〕 Although higher pulmonary arterial pressures are associated with the development of HAPE, the presence of pulmonary hypertension may not in itself be sufficient to explain the development of edema: severe pulmonary hypertension can exist in the absence of clinical HAPE in subjects at high altitude. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「High-altitude pulmonary edema」の詳細全文を読む スポンサード リンク
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