In TCD monitoring, what is the primary quantitative value measured?

In transcranial Doppler (TCD) monitoring, the primary quantitative value measured is velocity. TCD is a non-invasive ultrasound technique used to measure the speed of blood flow through the cerebral arteries. The main output of TCD is the velocity of blood flow, typically reported in centimeters per second (cm/s).

Measuring blood flow velocity is crucial for assessing cerebral hemodynamics, particularly during surgical procedures, as changes in velocity can indicate alterations in cerebral perfusion or the presence of vascular complications. Monitoring blood flow velocity helps in identifying conditions such as vasospasm, microemboli, or hemodynamic compromise, allowing for timely interventions.

Other parameters like amplitude, frequency, and duration play roles in the interpretation of the Doppler signal but are not the primary quantitative measures used in TCD monitoring.

Thus, the focus on velocity as the primary quantitative measure underscores its significance in evaluating cerebral blood flow during intraoperative procedures.