Use of duplex echoencephalography to evaluate brain death in children: A novel approach to the diagnosis.

Abstract

Brain death is defined as the irreversible cessation of brain function with a known etiology. This study aims to establish the value of duplex echoencephalography (DEG) in children fulfilling clinical brain death diagnostic criteria. DEG must show intracranial brain structures. Power Doppler is used to assess venous flow when feasible. Color Doppler patterns in all major arteries are assessed. Spectral analysis of arterial flow is divided into four grades: grade 1: inverted flow during entire diastole with time average peak velocity (TAPV) less or equal to zero; grade 2: disappearance of the inverted diastolic flow at the end of diastole; grade 3: oscillating pattern in early diastole; and grade 4: no diastolic flow with systolic blip. To fulfill diagnosis of brain death, brain perfusion must be lost for 30 minutes. DEG is performed in 41 pediatric patients. In infants, loss of venous flow occurs regardless of the etiology. Grade 1 is the most common arterial color flow pattern and TAPV is always below zero. A pulsatile color flow is associated with three other types of flow patterns (grades 2-4). TAPV is not calculated, when there is loss of diastolic flow. Diagnosis of brain death is validated using nuclear brain scan in 4patients. Two have a grade 1 flow pattern, while the other two have a grade 4 flow pattern. In children, DEG following a strict protocol can be used to confirm diagnosis of brain death in the appropriate clinical setting.