Respirator brain. Report of a survey and review of current concepts.

ABSTRACT

Because of renewed public and scientific interest in the concept of brain death and its diagnostic criteria, an opinion survey was undertaken, polling the membership of the American Association of Neuropathologists, regarding the definition, gross and microscopical features, and pathogenesis of the syndrome popularly designated the "respirator brain." Of the 191 respondents who completed the questionnaire, 174 (91%) indicated that the term respirator brain is properly used to describe a specific pathological entity, and 160 (84%) considered the characteristics of respirator brain to be distinct from those of late fixation. Of the 174 respondents who accepted the designation, 148 (85%) regarded a history of respiratory dependency as essential, and a vast majority (95%) agreed that extensive tissue necrosis occurs with little inflammatory cell reaction; other criteria were more controversial. Microscopical changes that suggest a pathogenetic mechanism attracted a number of informative, limiting, or qualifying remarks. Nonetheless, 54% thought that impaired cerebral blood flow contributed to pathogenesis.