[Brain death diagnosis].

Brain death has been recognized by the scientific community as the person's death, and accepted in the legislation of different countries. Brain death is defined as the irreversible ending of the functions of all the intracranial neurological structure in both the brain and brain stem. This clinical situation appears when intracranial pressure exceeds the patient's systolic blood pressure, leading to brain circulatory arrest. The most frequent are cerebral hemorrhage and cranioencephalic trauma. Clinical diagnostic must be done by doctors with expertise in neurocritical patient treatment. This diagnosis is based on a systematic, complete and extremely rigorous clinical examination that confirms a non-reactive coma, absence of brain stem reflex, and absence of spontaneous breathing. Instrumental tests may be obligatory in some cases, this depending on each country. Electroencephalogram and evoked potentials are the electrophysiological tests used. In patients treated with sedative drugs, cerebral blood flow evaluation tests, such as cerebral angiography, transcranial Doppler or 99Tc-HMPAO scintigraphy, will be used. More than 92% of the transplants performed in Spain are performed with brain death donor organs. Brain death confirmation is a high responsibility act, with medical, ethical and legal significance since it requires removal of all artificial support, or organs extraction for transplant. Extensive knowledge on its diagnostic and correct decision making avoid unnecessary use of resources and improves management of organs for transplant.