Diagnosing brain death using the transcranial Doppler with a transorbital approach.

BACKGROUND: Transcranial Doppler is a sensitive instrument for the diagnosis of brain death. The guidelines for the determination of brain death include the demonstration of specific blood flow patterns in the anterior and posterior circulation systems. A limitation of this method is the frequent false finding of no flow, especially when using the transtemporal approach in older women.

OBJECTIVE: To evaluate the efficacy of the transorbital approach in the diagnosis of brain death using transcranial Doppler.

METHODS: A prospective controlled, diagnostic test study was performed. Transorbital, transtemporal, and transforaminal approaches were used. Fifty-seven patients (29 men and 28 women; mean +/- SD age, 68.2 +/- 12.1 years) with clinically determined brain death were examined.

RESULTS: In 45 patients, oscillatory flow or systolic spikes were found in all approaches. In 4 patients, no flow was detected. In 6 patients, oscillatory flow or systolic spikes were found in 2 approaches, including the transorbital one. In 2 patients, a positive finding was demonstrated only using the transorbital approach. Using the transorbital approach, the percentage of positive findings with definitive diagnoses of brain death rose from 79% to 88%.

CONCLUSION: The transorbital approach is a useful addition for the diagnosis of brain death, using the transcranial Doppler technique.