Effects of Different Physiological States on TCD Flow Velocity
| Physiologic Factor | Effects |
|---|---|
| Increase age | Decrease FV |
| Increase CSF pressure | Decrease FV |
| Increase central venous pressure | Decrease FV |
| Increase PaCO2 | Increase FV due to vasodilatation |
| Increase cardiac output | Decrease FV to maintain normal CBF |
| Increased blood viscosity | Decrease FV |
| Anemia | Increase FV |
| Drugs with vasodilatation properties | Increase FV |
| Drugs with vasoconstriction properties | Decrease FV |
TCD, transcranial Doppler; CSF, cerebrospinal fluid; FV, flow velocity; CBF, cerebral blood flow.