在聖母峰脫褲 測出最低血氧量紀錄

[blind faith]

from 自由時報 〔編譯羅彥傑／綜合報導〕

頂著攝氏零下二十五度低溫與二十節的風速，在世界最高峰頂端附近脫褲子，即使是為了科學實驗，也可能被譏是匹夫之勇。不過，三十五歲的英國麻醉科醫師與重症照護專家馬丁不做如是想。他照辦了，目的是為治療重症病患另謀新法，但同時他也被檢測出已知的人類最低血液含氧量，足以列入世界紀錄。

馬丁的血氧測量結果先前被認為不符合實際情況，但他在聖母峰下方四百公尺的小岩脊上，從自己大腿鼠蹊處動脈抽取血液樣本時，還能正常行走與聊天，甚至替其他九名一起爬山的同僚們抽血。這項二○○七年五月的實驗成果，刊登在最新一期《新英格蘭醫學期刊》上。

這項實驗的目的是要了解，該如何照護罹患諸如囊胞性纖維症、肺氣腫、敗血性休克、急性呼吸窘迫症候群（ＡＲＤＳ）及藍嬰症等出現血液含氧量過低症狀的病患。包含馬丁在內的十名醫師攀爬到聖母峰峰頂下方、海拔八千四百公尺處，然後脫下氧氣罩，呼吸四周空氣達二十分鐘。

他們測量當氧氣稀薄時的人類生理變化，馬丁的血氧濃度為二．二五千帕（kPa），比正常值十二至十四千帕低了八十％，而且還不到通常導致緊急送加護病房的血氧濃度的一半。他們揣測，高空造成肺部液體集結，可能導致血氧濃度低。研究團隊領隊葛洛卡特說，低含氧量幾乎是重症照護的共同問題，「我們使用的某些干預措施，譬如提供氧氣、積極換氣，都可能是有害的。如果病患可以忍受低含氧量，我們就可以縮手不管，可能造成的傷害更小。」
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Arterial Blood Gases and Oxygen Content in Climbers on Mount Everest

Michael P.W. Grocott, M.B., B.S., Daniel S. Martin, M.B., Ch.B., Denny Z.H. Levett, B.M., B.Ch., Roger McMorrow, M.B., B.Ch., Jeremy Windsor, M.B., Ch.B., Hugh E. Montgomery, M.B., B.S., M.D., for the Caudwell Xtreme Everest Research Group

ABSTRACT

Background
The level of environmental hypobaric hypoxia that affects climbers at the summit of Mount Everest (8848 m [29,029 ft]) is close to the limit of tolerance by humans. We performed direct field measurements of arterial blood gases in climbers breathing ambient air on Mount Everest.

Methods
We obtained samples of arterial blood from 10 climbers during their ascent to and descent from the summit of Mount Everest. The partial pressures of arterial oxygen (PaO2) and carbon dioxide (PaCO2), pH, and hemoglobin and lactate concentrations were measured. The arterial oxygen saturation (SaO2), bicarbonate concentration, base excess, and alveolar–arterial oxygen difference were calculated.

Results
PaO2 fell with increasing altitude, whereas SaO2 was relatively stable. The hemoglobin concentration increased such that the oxygen content of arterial blood was maintained at or above sea-level values until the climbers reached an elevation of 7100 m (23,294 ft). In four samples taken at 8400 m (27,559 ft) — at which altitude the barometric pressure was 272 mm Hg (36.3 kPa) — the mean PaO2 in subjects breathing ambient air was 24.6 mm Hg (3.28 kPa), with a range of 19.1 to 29.5 mm Hg (2.55 to 3.93 kPa). The mean PaCO2 was 13.3 mm Hg (1.77 kPa), with a range of 10.3 to 15.7 mm Hg (1.37 to 2.09 kPa). At 8400 m, the mean arterial oxygen content was 26% lower than it was at 7100 m (145.8 ml per liter as compared with 197.1 ml per liter). The mean calculated alveolar–arterial oxygen difference was 5.4 mm Hg (0.72 kPa).

Conclusions
The elevated alveolar–arterial oxygen difference that is seen in subjects who are in conditions of extreme hypoxia may represent a degree of subclinical high-altitude pulmonary edema or a functional limitation in pulmonary diffusion.

N Engl J Med 360;2,140-149, January 8, 2009

[咖大]

太小題大作了
如果只是要做實驗
在平地利用密閉艙控制空氣中氧氣濃度就可達到類似效果
事實上在高山的醫學實驗非常多
包括登八千公尺高山前後胃鏡中胃部出血狀況
血氧監測
肺水腫
腦水腫
這些都有人做過了
脫褲子抽動脈血
真的是放屁多此一舉
(偽可愛)

[hsu]

在早產兒的治療早就把血氧濃度的標準降低很多
如此反而可以避免因積極的呼吸治療所造成的併發症

[sakura]

為什麼不從手腕抽radial artery的就好了.....?? (咦)

[genome]

為什麼不從手腕抽radial artery的就好了.....?? (咦)

零下二十五度耶
不戴手套的話 沒有辦法好好拿針吧 因為實在太冷了
大概不容易pon到radial artery
femoral artery如果事先畫好記號 就算帶手套也應該不難持針pon到
偶猜啦....

[blind faith]

題外話, 小問題.....
要 puncture radial artery 前, 要作甚麼 test?

[NZDoc]

題外話, 小問題.....
要 puncture radial artery 前, 要作甚麼 test?

Allen's test (勾拳一記)

[blind faith]

參考: http://en.wikipedia.org/wiki/Allen%27s_test

The utility of the Allen's test is questionable,and no direct correlation with reduced ischemic complications of radial artery cannulation have ever been proven. In 1983, Slogoff and colleagues reviewed 1,782 radial artery cannulations and found that 25% of them resulted in complete radial artery occlusion, without apparent adverse effects. A number of reports have been published in which permanent ischemic sequelae occurred even in the presence of a normal Allen's test. In addition, the results of Allen's tests do not appear to correlate with distal blood flow as demonstrated by fluorescein dye injections or photoplethysmography.

[好大]

太小題大作了
如果只是要做實驗
在平地利用密閉艙控制空氣中氧氣濃度就可達到類似效果
事實上在高山的醫學實驗非常多
包括登八千公尺高山前後胃鏡中胃部出血狀況
血氧監測
肺水腫
腦水腫
這些都有人做過了
脫褲子抽動脈血
真的是放屁多此一舉
(偽可愛)

這就叫話題性
下了山就變大師啦～