Doppler examination of cerebral arteries in uremic children.

Transcranial Doppler ultrasonography is a useful method for the estimation and monitoring of cerebral circulation in dialyzed patients. The aim of this study was to evaluate the effect of disease and treatment on cerebral circulation in children on maintenance hemodialysis (HD) and children prior to renal replacement therapy. We demonstrated that in uremic children blood flow velocities of the internal carotid artery (ICA), anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) 120 min and 240 min from the beginning of an HD session were significantly lower than values immediately before HD. Changes in blood flow velocities of MCA and ACA during HD correlated significantly with changes in mean arterial pressure during HD. There was no correlation between changes in blood flow velocities and intradialytic changes in hematocrit values, ultrafiltration, hemoglobin concentration, and blood urea nitrogen values. Mean blood flow velocities of ICA, MCA, and PCA in euvolemic children on conservative treatment were significantly higher than after a HD session in children on maintenance HD. The factors responsible for intradialytic velocity changes of cerebral arteries in uremic children require further examination.