The effect of asphyxia on superior mesenteric artery blood flow in the premature sheep fetus
The effect of asphyxia on superior mesenteric artery blood flow in the premature sheep fetus
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DOI：
10.1016/s0022-3468(00)80009-3
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发表时间：
2000-01-01
影响因子：
2.4
通讯作者：
Heineman, E
中科院分区：
文献类型：
--
作者：
Bennet, L;Quaedackers, JSLT;Heineman, E
背景/目的：本研究的目的是测定宫内窒息后未麻醉的早产羊在宫内窒息后肠系膜上动脉血流的变化。方法：对妊娠0.7天(103~104天)的早产羊进行25分钟完全脐带阻断(n=6)或假阻断(n=6)。分别于阻断前6h至阻断后3d测量胎心率、血压、肠系膜上动脉(SMA)血流量及血管阻力、脑电活动及颈项肌电活动。结果：阻断过程中，心血管反应表现为3个阶段：最初血流从肠道重新分配以维持重要器官功能，随后这种重新分配部分失败，最后心血管末期崩溃并伴有严重低血压和胃肠低灌流。窒息后出现二次低灌注期，这是由血管阻力增加而不是低血压引起的。结论：SMA血流量不仅在窒息过程中明显减少，而且在窒息后数小时内也明显减少。作者推测，胃肠道血流的这些扰动可能会损害肠壁的完整性，可能会增加坏死性小肠结肠炎的易感性。版权所有(C)2000，由W.B.Saunders公司提供。
Background/Purpose: The aim of this study was to determine superior mesenteric artery blood flow changes during and after an asphyxial insult in utero in chronically instrumented unanaesthetised premature fetal sheep.Methods: Fetal sheep at 0.7 gestation (103 to 104 days) underwent 25 minutes of complete umbilical cord occlusion (n = 6) or sham occlusion (n = 6). Fetal heart rate, blood pressure, superior mesenteric artery (SMA) blood flow and vascular resistance, electroencephalographic activity, and nuchal electromyographic activity were measured from 6 hours before occlusion until 3 days after occlusion. Fetal gastrointestinal tissue was taken for histological assessment.Results: During occlusion, cardiovascular response was characterised by 3 phases: initial redistribution of blood flow away from the gut to maintain vital organ function, subsequently partial failure of this redistribution, and finally near terminal cardiovascular collapse with profound hypotension and gastrointestinal hypoperfusion. Postasphyxia there was a secondary period of hypoperfusion that was mediated by increased vascular resistance, not hypotension. There was no evidence of injury on standard histological assessment after 3 days of recovery.Conclusions: SMA blood flow is not only significantly reduced during asphyxia, but also for several hours after an asphyxial insult. The authors speculate that these perturbations of gastrointestinal blood flow could compromise gut wall integrity potentially leading to increased vulnerability to necrotising enterocolitis. Copyright (C) 2000 by W.B. Saunders Company.