急診筆記

High Alt Med Biol. 2011 Fall; 12(3):207-14. doi: 10.1089/ham.2011.0007. Sildenafil citrate (Viagra,威而鋼) 預防高海拔低氧性肺動脈高壓雙盲隨機對照研究 Sildenafil citrate for the prevention of high altitude hypoxic pulmonary hypertension: double blind, randomized, placebo-controlled trial. PASP 肺動脈收縮壓 pulmonary arterial systolic pressure Bates MG1, Thompson AA, Baillie JK, Sutherland AI, Irving JB, Hirani N, Webb DJ.  Author information Abstract 這篇研究發表於 2011年秋天, 高海拔醫學雜誌 低氧性肺血管收縮是造成高海拔肺水腫 HAPE 的關鍵因素, 威而鋼有擴張肺血管的效果, 曾被認為可預防HAPE, 這篇研究是隨機雙盲對照實驗, 收錄 62位健康成人, 36名男性, 中位數年齡 21 歲(18-31歲), 於波利維亞的拉帕斯山谷, 海拔 3650 公尺, 在研究考察的行程,  經過四到五天高度適應, 於 90 分鐘內攀升至海拔 5200 公尺 實驗組 20 人服用每次 50mg 威而鋼, 每天三次, 使用心臟超音波測量海平面, 及抵達海拔 5200 公尺後六小時內, 三天, 一周, 肺動脈壓力.  Exaggerated hypoxic pulmonary vasoconstriction is a key factor in the development of high altitude pulmonary edema (HAPE). Due to its effectiveness as a pulmonary vasodilator, sildenafil has been proposed as a prophylactic agent against HAPE. By conducting a par...

Wilderness medicine at high altitude: recent developments in the field Nitrates 體內一氧化氮 NO 生成, 可調節血管收縮狀態, 免疫功能, 血小板凝集, 血糖平衡, 肌肉收縮, 粒線體功能. 目前有證據顯示NO與高度適應有關, 在高度適應過程, NO 生成會增加, 低氧引起的適應反應在西藏人很明顯, 他們血清亞硝酸鹽濃度較高, 代表整體NO合成上升, 吐氣排出的NO也較多.  Nitric oxide (NO) regulates physiological processes in the human body, including vasodilation, immune function, platelet aggregation, glucose homeostasis, muscle contraction, and mitochondrial function. Emerging evidence suggests that NO also plays an important role in altitude acclimatization. Lowlanders exposed to altitude initially exhibit reduced concentrations of exhaled NO, with the magnitude of this decline associated with susceptibility to altitude illness. With acclimatization, lowlanders demonstrate an increase in NO production. The adaptive response to hypoxia is particularly prominent in Tibetans who have greater plasma nitrite concentrations, indicative of elevated whole-body NO production, and higher exhaled NO relative...