Carotid blood-flow velocity changes detected by Doppler ultrasound in determination of brain death in children. A preliminary report.

To investigate the value of Doppler ultrasonography of the carotid arteries as a diagnostic test for the determination of brain death in children, we enrolled 17 patients in a blinded fashion in the pediatric intensive care unit of Memorial Miller Children's Hospital of Long Beach between the period of December 1990 and October 1992. After institutional review board approval and parental consent, children who sustained severe brain injury underwent Doppler ultrasonography study of their carotid arteries. Seven of 17 patients were diagnosed as having brain death by clinical criteria (complete loss of cerebral and brainstem functions) and electroencephalogram (EEG). Five of seven (71%) patients with the diagnosis of brain death had bilateral reverse flow (characteristic of increased cerebrovascular resistance and absent cerebral circulation) on their Doppler ultrasonography, yielding a specificity of 100% and sensitivity of 71.4% (P = 0.01). All surviving patients (five) and the five who did not fulfill the brain-death criteria at the time of Doppler ultrasonography and were later taken off life supportive measures had normal Doppler findings. These data indicate that Doppler ultrasonography of the carotid arteries is a very specific test and can be used as an adjunctive modality for determination of brain death in children.