Humphrey P R
Scand J Clin Lab Invest Suppl. 1981;156:209-11. doi: 10.3109/00365518109097464.
Evidence suggests that haematocrit and viscosity are important factors in the control of cerebral blood flow (CBF). Conditions in which the haematocrit is raised, such as polycythaemia rubra vera and relative polycythaemia are associated with a low CBF. Following reduction in haematocrit, there is a significant rise in CBF. It is likely that two factors are responsible for this. Firstly there is a fall in oxygen carrying capacity with venesection. Secondly there is a marked fall in whole blood viscosity. Both these changes tend to result in a rise in CBF. Further studies in patients with paraproteinaemias suggest that oxygen carriage and blood viscosity are independent variables in the control of CBF.
有证据表明，血细胞比容和血液粘度是控制脑血流量（CBF）的重要因素。血细胞比容升高的情况，如真性红细胞增多症和相对性红细胞增多症，与低脑血流量相关。血细胞比容降低后，脑血流量会显著增加。这可能由两个因素导致。首先，放血会使携氧能力下降。其次，全血粘度会显著降低。这两种变化都倾向于导致脑血流量增加。对副蛋白血症患者的进一步研究表明，氧运输和血液粘度是控制脑血流量的独立变量。
