Rosenkrantz T S, Stonestreet B S, Hansen N B, Nowicki P, Oh W
J Pediatr. 1984 Feb;104(2):276-80. doi: 10.1016/s0022-3476(84)81012-4.
We measured hematocrit, whole blood viscosity, arterial oxygen content, and cerebral blood flow in seven newborn lambs in which polycythemia and hyperviscosity were induced by partial exchange transfusion with packed red blood cells from a donor lamb. After the exchange transfusion, the hematocrit, whole blood viscosity, and arterial oxygen content were significantly elevated, whereas cerebral blood flow was reduced from baseline measurements. Sodium nitrite was then infused to reduce the arterial oxygen content to baseline values while the hematocrit and viscosity remained elevated. Under this condition, cerebral blood flow returned to baseline values. Oxygen delivery to the brain remained constant throughout the study. These results indicate that the reduction of cerebral blood flow in neonatal polycythemia and hyperviscosity is a physiologic response to increased arterial oxygen content and not a result of hyperviscosity.
我们对7只新生羔羊进行了血细胞比容、全血粘度、动脉血氧含量和脑血流量的测量，这些新生羔羊通过与供体羔羊的浓缩红细胞进行部分换血而诱发了红细胞增多症和高粘度血症。换血后，血细胞比容、全血粘度和动脉血氧含量显著升高，而脑血流量较基线测量值降低。随后输注亚硝酸钠，将动脉血氧含量降至基线值，而血细胞比容和粘度仍保持升高。在此条件下，脑血流量恢复到基线值。在整个研究过程中，脑氧输送保持恒定。这些结果表明，新生儿红细胞增多症和高粘度血症时脑血流量的减少是对动脉血氧含量增加的一种生理反应，而非高粘度的结果。
