EFFECTS OF LONG-TERM, HIGH-ALTITUDE HYPOXEMIA ON OVINE FETAL CARDIAC-OUTPUT AND BLOOD-FLOW DISTRIBUTION
EFFECTS OF LONG-TERM, HIGH-ALTITUDE HYPOXEMIA ON OVINE FETAL CARDIAC-OUTPUT AND BLOOD-FLOW DISTRIBUTION
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DOI：
10.1016/0002-9378(93)90646-z
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发表时间：
1993-09-01
影响因子：
9.8
通讯作者：
GILBERT, RD
中科院分区：
文献类型：
--
作者：
KAMITOMO, M;ALONSO, JG;GILBERT, RD
目的：我们试图确定长期低氧血症对胎儿心输出量和流量分布的影响。研究设计：我们将六只怀孕羊在妊娠 30 至 135 天（足月 146 天）期间暴露于高海拔（3820 m）缺氧环境。手术后 10 至 14 天，我们通过放射性标记微球技术在基线期间以及在更严重的急性低氧血症的额外 30 分钟期间测定胎儿心输出量和器官血流量。 结果：母体动脉 PO2 基线为 60.7 +/- 1.7 托，在急性低氧血症期间降至 35.1 +/- 3.0 托。在急性低氧血症期间，胎儿动脉 PO2 从 18.5 +/- 1.1 下降至 11.4 +/- 1.5 托。基线胎儿心输出量为 351 +/- 55 ml/min/kg，显着低于先前报告的低海拔胎儿值。流向心脏和大脑等关键器官的血流量维持在低海拔胎儿的水平，但流向尸体的血流量明显低于文献报道的低海拔胎儿的平均值（-49%）。大脑和心脏的氧气输送量也保持在正常水平，但肾脏（31%）、胃肠道（51%）和屠体（-58%）的氧气输送量减少。在急性低氧血症期间，心输出量没有显着变化；然而，流向大脑、心脏和肾上腺的血流量分别增加了 112%、135% 和 156% (p < 0.05)。 结论：我们的结论是，在长期低氧血症期间，胎儿心输出量的重新分配保持有利于大脑和心脏。
OBJECTIVE: We sought to determine the effects of long-term hypoxemia on fetal cardiac output and flow distribution.STUDY DESIGN: We exposed six pregnant sheep to high altitude (3820 m) hypoxia from 30 to 135 days' gestation (term 146 days). Ten to 14 days after surgery we determined fetal cardiac output and organ blood flows by means of the radiolabeled microsphere technique during a baseline period and also during an additional 30-minute period of more severe added acute hypoxemia.RESULTS: Baseline maternal arterial PO2 was 60.7 +/- 1.7 torr and fell to 35.1 +/- 3.0 torr during the added acute hypoxemia. Fetal arterial PO2 decreased from 18.5 +/- 1.1 to 11.4 +/- 1.5 torr during added acute hypoxemia. Baseline fetal cardiac output was 351 +/- 55 ml/min/kg, which was significantly lower than previously reported values in low-altitude fetuses. Blood flow to critical organs such as the heart and brain was maintained at levels found in low-altitude fetuses, but flow to the carcass was significantly lower (-49%) than the mean value reported in the literature for low-altitude fetuses. Oxygen delivery was also maintained at normal levels to the brain and heart but was reduced in the kidneys (31%), gastrointestinal tract (51%), and carcass (-58%). During added acute hypoxemia cardiac output did not change significantly; however, blood flow to the brain, heart, and adrenal glands increased 112%, 135%, and 156% (p < 0.05), respectively.CONCLUSION: We conclude that during long-term hypoxemia redistribution of fetal cardiac output is maintained favoring the brain and heart.