*La ME se define como el cese irreversible en las

funciones de todas las estructuras neurológicas

intracraneales, tanto de los hemisferios

cerebrales como del troncoencéfalo.

*Esta situación clínica aparece cuando la presión

intracraneal (PIC) se eleva por encima de la

presión arterial sistólica (PAS) del paciente, lo

que da lugar a la parada circulatoria cerebral.

*The Canadian forum on NDD defined

neurologically determined death as the

irreversible loss of the capacity for

consciousness combined with the irreversible

loss of all brain stem functions, including the

capacity to breathe.

*In the United States, the Uniform Determination

of Death Act defines “brain death” as the

irreversible cessation of all functions of the

entire brain, including the brainstem.

*

*Pallis and Harley14 of the United Kingdom define the time of

the first assessment for brain death as the point when the

preconditions for the diagnosis of brain death have been met;

unresponsive apneic coma, a cause of coma capable of

producing brain death, and a determination that the damage

is irremediable.

*The Australian and New Zealand Intensive Care Society

guidelines recommend that no fewer than 4 hours of

documented coma should precede the first examination for

brain death.

*The time of the first assessment for brain death is the point when the preconditions for the diagnosis of brain death have been met, with the following exceptions:

* In cases of acute hypoxic-ischemic brain injury, clinical evaluation for NDD should be delayed for 24 hours after the cardiorespiratory arrest or when an ancillary test could be performed.

* In cases of extreme metabolic insult, enough time should have passed for the clinician to think that the insult is permanent and there should be evidence of diffuse cerebral insult on imaging (magnetic resonance imaging [MRI]). If irreversibility remains an issue, an ancillary test should be performed in addition to the clinical examination.

*

*Based on this evidence, the AAN guidelines state that a single

examination suffices to establish the diagnosis but that US

state statutes require 2 examinations, especially in the

context of organ donation.

*The Canadian guidelines state that for the purposes of a

postmortem transplant, the fact of death shall be determined

by at least 2 physicians. The examinations may be performed

concurrently. However, if the determinations are performed

at different times, a full clinical examination, including

apnea testing, must be performed at each determination. No

fixed interval of time is recommended for the second

determination except when age-related criteria apply.

*

*Estabilidad cardiocirculatoria

*Oxigenación y ventilación

adecuada

*Ausencia de hipotermia grave.

*

*Alteraciones metabólicas

*Intoxicaciones

*Depresores del SNC.

*Muerte tronco-encefálica aislada: Loss of ascending reticular activating system function would lead to the loss of consciousness the hypothalamus and interruption of the corticothalamic tract in his diagrams as an extended brainstem.

*

*COMA ARREACTIVO

*AUSENCIA DE REFLEJOS TRONCO-ENCEFALICOS.

*AUSENCIA DE AUTONOMIA RESPIRATORIA: Test

de atropina, test de apnea.

*ACTIVIDAD MOTRIZ ESPINAL

*

*ELECTROENCEFALOGRAMA

*POTENCIALES EVOCADOS.

*DOPPLER TRANSCRANEAL

*GAMAGRAFIA CEREBRAL

*ARTERIOGRAFIA CEREBRAL

*

*RECOMMENDATIONS*The criteria for the determination of brain death given in the 1995

AAN practice parameter have not been invalidated by published reports of neurologic recovery in patients who fulfill these criteria.

*2. There is insufficient evidence to determine the minimally acceptable observation period To ensure that neurologic functions have ceased irreversibly.

*3. Complex-spontaneous motor movements and false-positive triggering of the ventilator may occur in patients who are brain dead.

*4. There is insufficient evidence to determine the comparative safety of techniques used for apnea testing .

*5. There is insufficient evidence to determine if newer ancillary tests accurately confirm the cessation of function of the entire brain.

*

*Capítulo VI

*De la Voluntad de Donación

*Artículo 10.- Voluntad Presunta.- Es la presunción legal que

establece que todos los ecuatorianos y extranjeros residentes

legalmente en el país, mayores de dieciocho años, al fallecer se

convertirán en donantes a menos que en vida hubiesen

manifestado su voluntad en contrario, de acuerdo a lo

establecido en el artículo 29 de la ley.