Blood rheology and pregnancy.
Blood rheology and pregnancy.
复制标题
DOI：
10.1016/s0950-3536(87)80024-0
复制
发表时间：
1987-09-01
期刊：
影响因子：
--
通讯作者：
Heilmann, L
中科院分区：
文献类型：
--
作者：
Heilmann, L
妊娠是一种高血容量状态，早期血浆容量增大，心输出量高，血管和血液流变性阻力降低。血浆体积的增加与胎儿大小的相关性比与母体大小的相关性更好。伴随着正常妊娠的高血容量和血管扩张状态导致子宫动脉的高流量。相比之下，妊娠高血压综合征(妊高征)或胎盘功能不全的患者可能会因弥漫性血管收缩而导致血浆容量收缩。尽管有强烈的血管痉挛和低血容量，先兆子痫的心输出量通常与非子痫前期妊娠相同、更高或更低。低血容血症表现为红细胞压积高于正常。在低血容量状态的情况下，血液浓度与高红细胞聚集有关。在胎儿窘迫和重度妊高征中，血液流变学状态(血液浓度和红细胞聚集性升高)对围产期并发症有很高的预测价值。重度妊高征患者的红细胞滤过功能受损。妊高征组患者的白细胞计数升高可能导致小血管闭塞，并可能是影响绒毛间血流的一个因素。红细胞刚性的增加可能是由于细胞钙代谢的重新分布(Blaustein概念)。我们得出的结论是，妊娠期的最佳红细胞压积在30%到38%之间。高红细胞压积的存在和红细胞聚集性的升高应该提醒内科医生胎儿受损的风险增加。
Pregnancy is a hypervolaemic situation with early expanded plasma volume, a high cardiac output and a decrease in the vascular and rheological resistance. The increase in plasma volume correlates better with fetal size than maternal size. The hypervolaemic and vasodilated state that accompanies normal pregnancy results in a high flow in the uterine arteries. In contrast, patients with PIH (pregnancy-induced hypertension) or placental insufficiency may have a contracted plasma volume secondary to diffuse vasoconstriction. In spite of the intense vasospasm and hypovolaemia, pre-eclampsia has generally a cardiac output which may be equal, higher or lower compared with non-eclamptic pregnancy. Hypovolaemia is reflected in a higher haematocrit than normal. In the case of a hypovolaemic state, haemoconcentration is associated with high red cell aggregation. In fetal distress and severe PIH, the rheological status (haemoconcentration and elevated red cell aggregation) has a high predictive value for perinatal complications. In patients with severe PIH, erythrocyte filtration is impaired. The increased leukocyte count in patients with PIH may occlude small vessels and could be a factor impairing intervillous blood flow. The increased erythrocyte rigidity may result from a re-distribution of cellular calcium metabolism (Blaustein concept). We conclude that there is an optimal haematocrit during pregnancy between 30% and 38%. The presence of a high haematocrit and in addition elevated red cell aggregation should alert the physician to an increased risk of fetal compromise.