Please, no more hyperoxia!

分類:熱門文章 建立於 2008-06-01, 週日 最近更新於 2012-11-10, 週六 作者 林鎮均
不知道別人的經驗是怎樣,個人過去常常碰到神經外科的同仁對於接受腦部手術後的病患予以100% O2,他們主張的理論是維持較高的PaO2可以增加腦部的氧利用率。我一直都反對這樣的治療,因為腦部在還沒有得到好處之前可能先會被氧毒性所傷害。現在有一篇review可以讓我的主張更有理論根據了。Current opinion in Critical Care Volume 14(2), April 2008, p 167–171有一篇關於這個議題的review,Hyperoxia: good or bad for the injured brain? 這篇文章說穿了重點就只有一個 CaO2 =  1.36  x  Hgb  x  SaO2  +  (0.003 x PaO2),也就是溶於血漿中的O2是可以忽略的。作者的結論是:
"Normobaric hyperoxia is a simple and appealing approach to the treatment of patients with traumatic brain injury(TBI). Initial enthusiasm developed on the basis of the ability of hyperoxia to improve brain oxygen tension and the availability of clinical tools to continuously measure it. Subsequent studies, however, which used measures more directly related to oxygen metabolism, were equivocal. Recent direct measures of cerebral metabolic rate for oxygen (CMRO2) in TBI patients indicate no benefit. This finding, along with the potential toxicity of hyperoxia, should preclude clinical use of hyperoxia until clear clinical benefit is demonstrated in prospective randomized controlled trials. Limited studies with hyperbaric hyperoxia suggest metabolism may improve, but better studies are needed; it is cumbersome and limited to centers with hyperbaric chambers."