Monitoring of severe head-injured patients with transcranial Doppler (TCD) ultrasonography.

Intracranial haemodynamics were studied in 36 patients with severe head injury and experimental animals with acute intracranial hypertension by the use of TCD ultrasound. The mean flow velocity (FV) in the basal cerebral arteries commonly decreased on the side of the haematoma depending on intracranial pressure (ICP) elevation and cerebral perfusion pressure (CPP) reduction in focal brain injury. The FV decreased bilaterally and there was no difference between the right and left sides in diffuse brain injury without a clear relationship between the FV and CPP. The FV of the middle cerebral artery and blood flow in the internal carotid artery exhibited flow patterns which changed correlatively depending on CPP reduction in experimental animals. Monitoring with TCD ultrasound is valuable in evaluating compression ischaemia in focal brain injury. But many complicated factors are considerable in diffuse brain injury.