[Recommendations of the use of transcranial Doppler to determine the existence of cerebral circulatory arrest as diagnostic support of brain death].

Introduction: The clinical criteria for brain death consist of the demonstration of the absence of any clinical sign of encephalic activity. Confirmatory testing is usually not required for the diagnosis of brain death, except in some special situations that the Spanish law details. In these situations demonstrating cerebral circulatory arrest (CCA) by cerebral flow studies is necessary to support the diagnosis of brain death.