Morte Encefálica
Brain Death
Hercília Mayumi Homi, Bomfim Alves da Silva Jr, Irineu Tadeu Velasco
Resumo
Justificativa e Objetivos - O anestesiologista tem participado de procedimentos cirúrgicos relativos aos transplantes de órgãos e tecidos que envolvem doadores com o diagnóstico de morte encefálica. Pode defrontar-se também com o problema nas unidades de recuperação pós-anestésica e unidades de terapia intensiva. O objetivo desta revisão é verificar os novos critérios para o diagnóstico de morte encefálica. Conteúdo - O diagnóstico da morte encefálica envolve um exame clínico adequado e exames complementares. Na investigação clínica deve ser feito o diagnóstico etiológico do coma. No exame clínico devem ser avaliados os reflexos do tronco cerebral, pupilar, corneano, nauseoso, óculovestibulares e os movimentos dos olhos. Os exames complementares utilizados para o diagnóstico da morte encefálica são divididos segundo o tipo de parâmetro fisiológico estudado. O fluxo sangüíneo cerebral pode ser estudado pela angiografia cerebral, cintilografia radioisotópica, tomografia por emissão de fóton único, tomografia cerebral com xenônio, tomografia por emissão de positrons e doppler transcraniano. A atividade metabólica cerebral é estudada pela tomografia por emissão de positrons. A atividade elétrica é avaliada pelo EEG e pelos potenciais evocados somatossensitivos. Conclusões - Com exame clínico acurado e alguns exames complementares pode-se hoje, com mais segurança, atestar a morte em pacientes com perda irreversível das funções cardiorrespiratórias e cerebrais.
Palavras-chave
Abstract
Background and Objectives - Anesthesiologists have participated in organ and tissue transplantation surgeries involving donors with brain death. They may also face the problem in post-anesthetic care units and intensive care units. This review aimed at evaluating new criteria for diagnosing brain death. Content - Brain death diagnosis involves an adequate clinical examination as well as complementary exams. During clinical investigation, the etiologic diagnostic of comma must be established. Clinical exams shall include brainstem, pupils, cornea, nausea, ocular-vestibular reflexes and eye movement. Complementary exams for diagnosing brain death are divided according to the physiologic parameter being investigated. Brain blood flow may be evaluated by brain angiography, radioisotope cyntilography, single photon emission tomography, brain tomography with xenon, positron emission tomography and transcranial doppler. Brain metabolic activity is evaluated by positron emission tomography. Electric activity is evaluated by EEG and somatosensory evoked potentials. Conclusions - With an accurate clinical evaluation and some complementary exams it is safer today to certify death in patients with irreversible loss of cardiopulmonary and brain functions.
Keywords
Referências
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