Transcranial Doppler ultrasonography in the neurologic intensive care unit.
Transcranial doppler ultrasonography (TCD) is a noninvasive monitoring tool which allows imaging of blood flow velocities in intracranial blood vessels. It is safe, portable, easy to perform and provides accurate information regarding underlying physiology which may help to guide therapy in critically ill neurologic patients. It has significantly contributed to the management of vasospasm related to subarachnoid hemorrhage in the neurologic intensive care unit. TCD is also helpful in the early diagnosis of a variety of complications that can occur in patients with head injury such as vasospasm, elevated intracranial pressure and disordered cerebral autoregulation. Careful performance of the test and experienced interpretation can identify TCD waveforms indicative of cerebral circulatory arrest, an ancillary finding used for the diagnosis of brain death. TCD is likely to play a larger role in evaluation of the patient in the future because of its safety, portability and ability to define moment-to-moment changes in cerebral blood flow velocities and cerebral blood flow.
Singh
V
V
Neurovascular Service, Department of Neurology, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, California 94143, USA.
McCartney
J P
JP
Hemphill
J C
JC
D001783:Blood Flow Velocity; D001926:Brain Death / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000000981:diagnostic imaging; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging; D006259:Craniocerebral Trauma / Q000000981:diagnostic imaging; D003422:Critical Care; D006801:Humans; D019586:Intracranial Hypertension / Q000000981:diagnostic imaging; D008991:Monitoring, Physiologic; D009422:Nervous System Diseases / Q000000981:diagnostic imaging* / Q000628:therapy; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging; D017585:Ultrasonography, Doppler, Transcranial / Q000295:instrumentation / Q000379:methods