ABSTRACT
Neurosonological studies, specifically transcranial Doppler (TCD) and transcranial color-coded duplex (TCCD), have high level of specificity and sensitivity and they are used as complementary tests for the diagnosis of brain death (BD). A group of experts, from the Neurosonology Department of the Brazilian Academy of Neurology, created a task force to determine the criteria for the following aspects of diagnosing BD in Brazil: the reliability of TCD methodology; the reliability of TCCD methodology; neurosonology training and skills; the diagnosis of encephalic circulatory arrest; and exam documentation for BD. The results of this meeting are presented in the current paper.
Estudos neurossonológicos, especialmente o Doppler transcraniano (DTC) e o duplex transcraniano codificado a cores (DTCC), apresentam elevados níveis de especificidade e sensibilidade quando utilizados como exames complementares no diagnóstico de morte encefálica (ME). Um grupo de peritos do Departamento Científico de Doppler transcraniano da Academia Brasileira de Neurologia criou uma força-tarefa de forma a determinar os critérios neurossonológicos para os seguintes aspectos no diagnóstico de ME no Brasil: metodologia do DTC; metodologia do DTCC; treinamento e habilidades em Neurossonologia; diagnóstico de parada circulatória encefálica e documentação do exame para a ME. Os resultados deste encontro foram apresentados neste artigo.
Subject(s)
Humans , Brain Death , Health Personnel/education , Ultrasonography, Doppler, Transcranial/standards , Brazil , Cerebrovascular Circulation , Inservice Training/standards , Predictive Value of Tests , Reproducibility of Results , Sensitivity and Specificity , Ultrasonography, Doppler, Transcranial/methodsABSTRACT
Background: The clinical diagnosis of brain death is complex. Aim: To evaluate the diagnostic accuracy of transcranial Doppler (TCD) for brain death. Patients and Methods: Patients seen on the intensive care unit of a private hospital between January 2004 to December 2008, were included if they were in structural coma, had no craniectomy and had a blind evaluation by a neurologist and TCD done in less than three hours. The diagnosis of brain death was based on a clinical evaluation that considered the absence of sedative drugs, median blood pressure >60 mmHg, body temperature over 35º Celsius and complete absence of brainstem refexes. An expert neurosonologist, with a TCD-PMD-100, 2 Mhz transducer, used an institutional protocol that considers the examination as positive for brain circulatory arrest when there is presence of reverberating, small systolic peaks or the disappearance of a previous signal present on both middle cerebral arteries and intracranial vertebral arteries. Results: Fifty three patients were evaluated, 25 with clinical brain death. On 45 cases (84.9 percent), the interval between both evaluations was less than one hour. The sensitivity, specifcity, positive and negative predictive values for the diagnosis of brain death with TCD were 100, 96, 96.1 and 100 percent respectively. Positive and negative likelihood ratios for brain death were 28 and 0, respectively. Conclusions: TCD is a valid and useful technique for the diagnosis of brain death and can be used on complicated cases.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Brain Death , Ultrasonography, Doppler, Transcranial/standards , Double-Blind Method , Middle Cerebral Artery , Prospective Studies , Sensitivity and Specificity , Vertebral Artery , Young AdultABSTRACT
Atualmente, as controvérsias sobre os benefícios da craniectomia descompressiva no tratamento de doentes com tumefação encefálica pós-traumática ainda existem. Não há estudos disponíveis na literatura médica sobre os efeitos da craniectomia descompressiva na hemodinâmica encefálica avaliados pelo Doppler transcraniano. Estudamos dois doentes com tumefação encefálica pós-traumática associada à hipertensão intracraniana e evidências de herniação transtentorial. Um deles foi submetido à craniectomia bifrontal e outro, à craniectomia frontoparietotemporal unilateral. O primeiro doente apresentou seqüela neurológica moderada e reintegração social, enquanto o segundo manteve-se em estado vegetativo. Exames de Doppler transcraniano realizados imediatamente antes e após a cirurgia revelaram aumento significativo da velocidade do fluxo sangüíneo nas artérias intracranianas de ambos os doentes. Concluiu-se que a craniectomia descompressiva com plástica de ampliação da dura-máter pode resultar em elevação da velocidade do fluxo sangüíneo encefálico nestes doentes. O aumento da velocidade do fluxo sangüíneo pode ocorrer nos hemisférios cerebrais do lado operado e, também, do lado oposto.