[Diagnosis of brain death using trancranial Doppler ultrasonography in an experimental model of organ donation for transplantation].

OBJECTIVE: To create an experimental organ donor model and validate it by ultrasound evaluation of intracranial blood flow velocity.

MATERIAL AND METHOD: Ten white New Zealand rabbits were assigned to either a control group or an experimental group. Brain death was induced in the experimental group by way of severe cranial hypertension. A diagnosis of brain death was based on physical examination and velocity of intracranial blood flow determined by transcranial doppler ultrasonography. Physical and ultrasound examinations were performed on all animals at baseline and at the time of the experiment.

RESULTS: Physical examination and intracranial blood flow velocity were normal in the control group animals at baseline and during the study. The findings were also normal for the experimental group animals at baseline. After provocation of intracranial hypertension, we observed signs of brain death (absence of response to pain stimulus in one cranial par absence of brainstem reflexes, and apnea) in the experimental animals, and the velocity of flow in arteries at the base of the skull acquired the waveform known as sharp systolic peaks, which are characteristic of cerebral circulation failure.

CONCLUSIONS: The results of physical examination and ultrasonography in this study provide adequate validation of this experimental model of brain death and demonstrate that transcranial doppler ultrasonography is useful for diagnosing brain death in the rabbit.