[Cerebral Blood flow velocity spectrum by transcranial doppler ultrasound in patients with brain death clinical criteria].
OBJECTIVE
To evaluate cerebral blood flow (CBF) direction, speed, and shape of Doppler profile in patients with clinical criteria of brain death (BD).


METHODS
A total of 42 consecutive patients with clinical criteria for BD were included.


METHODS
After anemia, hypothermia and hypocapnia were ruled out; confirmatory electroencephalogram (EEG) and a complete transcranial Doppler ultrasonography (TCDU) profile of circle of Willis and basilar arteries were done in all patients. Patients continued with mechanical ventilation and support in the Intensive Care Unit.


RESULTS
All EEG reported generalized theta and delta waves, which were associated with a TCDU profile showing small systolic peaks without diastolic wave. CBF velocities of < 10 cm/sec were recorded in all patients. Only four patients had reverberating flow. At follow-up, cardiac arrest occurred in all patients at a mean of 2 +/- 0.84 days.


CONCLUSIONS
Patients with clinical criteria of BD frequently have slow wave neuronal electrical activity on EEG that anticipates cardiac arrest. In these patients, TCDU detects an early and severe drop in CFB that is incompatible with life. TCDU should be done when other confirmatory tests like EEG suggest some retention of brain function.
Deseano-Estudillo
José Luis
JL
Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico, D.F. estudilo@prodigy.net.mx
Castañón-González
Jorge Alberto
JA
Carbajal-Ramírez
Angélica
A
Castrejón-Román
Hugo
H
León-Gutiérrez
Marco Antonio
MA
D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply*; D001926:Brain Death / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*