社会的構成概念としての脳死 : 合理的な臓器移植大国アメリカにおける脳死の今日的理解  [in Japanese] Brain death is a social construct  [in Japanese]

1997年の「臓器の移植に関する法律」の施行以来、脳死からの臓器移植に関する諸問題は、そのほとんどが片付き、残る課題の中心は、小児からの臓器摘出の可否の検討とドナー増を図ること、と考えられている。しかし、日本も採用している全脳死の概念への疑義が「臓器移植先進国」アメリカで再燃し、本質的な問題は、再び、「脳死とは何か」に戻ってきている。「脳死は人の死」というのは過去の理解であり、今やアメリカで移植医療に関わる医師や生命倫理研究者は、全脳死の概念を「論理的整合性を若干欠いていても、移植医療を支える社会的構成概念として有用」と理解しているが、ドナーになる一般市民はこれを知らない。しかし、善意のドナーが臓器移植システムの土台を成す以上、一般市民には正確な情報が与えられなければならない。善意のドナーの誤解を利用したまま臓器移植システムを運営することは許されない。

The issue of what constitutes brain death seems yesterday's controversy. It is true that in the past few decades, brain death has become widely accepted in technologically advanced countries. But behind the consensus, some now argue, is the fact that brain-dead patients make ideal organ donors. The criteria for whole-brain death proposed in the United States in 1968 originally served two purposes-the withdrawal of life-sustaining treatment from those determined to be brain-dead and the procurement of organs for transplantation from such patients. But in the years since the report, the diagnosis of brain death has become less relevant to the former purpose. Now life-support is withdrawn from patients with less severe degrees of neurological dysfunction in the U.S. Opponents of brain death in the U.S. say that very few patients they diagnose as brain-dead actually meet the criteria for brain death-the permanent cessation of functioning of the entire brain. They say that the current science tells that the concept of brain death is incoherent in theory. Proponents of brain death say that brain death may look like an arbitrary line drawn between life and death, but it is practical and useful. A champion of the definition admits that brain death is a kind of social construct. He says that even though it is not a perfect concept, it is still sufficiently coherent to design a workable public policy, in other words, to maintain the organ transplantation enterprise. Now an increasing number of doctors understand that brain death is a social construct maintained for the irresistible utilitarian purpose. Some of them predict that no one will be diagnosed brain dead in the future because there will be no need. Professionals say that lay people know little about the emerging argument. But the public should be informed about it because the organ transplantation system relies on good-will donors.