[Value of the transcranial Doppler examination in the diagnosis of brain death].

BACKGROUND

Transcranial Doppler examination (TCD) is a non invasive method capable of detecting the interruption of cerebral flow in patients with criteria of brain death. Its recognition as an alternative to isoelectric EEG for the diagnosis of brain death requires previous validation.

METHODS

Twenty-six patients in profound coma were examined by TCD. Of 23 patients with technically adequate study 13 manifested clinical criteria and EEG of brain death. Of these patients 9 had received barbiturate treatment and 4 had not.

RESULTS

Changes in the flow waves of the TCD were observed in the form of diastolic reflux or systolic points of slight amplitude without diastolic flow in at least 2 arteries in 12 of 13 patients with criteria of brain death (sensitivity = 92%) and in none of the 10 patients without criteria of brain death (specificity = 100%). The use of barbiturates did not modify the normal anterograde flow detected by TCD in the absence of criteria of brain death.

CONCLUSIONS

Transcranial Doppler is a good method for confirming the clinical diagnosis of brain death, fundamentally in patients undergoing treatment with drugs depressing the central nervous system.