Accuracy of Power Mode Transcranial Doppler in the Diagnosis of Brain Death

Abstract

The diagnosis of brain death (BD) is complex. For this reason, we aimed to evaluate the accuracy of power mode transcranial Doppler (PMD-TCD) in diagnosing BD. Patients and methods: Patients admitted to an intensive care unit between December 2003 and January 2012 were included in this study if they were in a structural coma, had no craniectomy, and were evaluated blind by a neurologist using PMD-TCD. The diagnosis of BD was based on an evaluation that took into consideration the absence of sedative drugs, a median blood pressure >60 mmHg, a body temperature >35°C, and the absence of brainstem reflexes. A neurosonologist followed a protocol using PMD-TCD that considered the examination as positive for brain circulatory arrest given the presence of reverberating, small systolic peaks or the disappearance of a previous signal present in both middle cerebral arteries and intracranial vertebral arteries. Results: A total of 74 patients were evaluated. In 61 (82.4%) patients the interval between both evaluations was less than 1 hour. The sensitivity and specificity for the diagnosis of BD with PMD-TCD were 100% and 98%, respectively. The positive and negative likelihood ratios for BD were 45 and 0, respectively. Conclusion: PMD-TCD is accurate for the diagnosis of BD.

Keywords

• brain death
• Doppler ultrasound
• power mode transcranial Doppler ultrasound
• ultrasound Doppler sonography
• ultrasound diagnosis