Kim-Egloff C, Hässig M, Bruckmaier R, Bleul U
Large Animal Reproduction Unit, Clinic for Reproductive Medicine, Department of Farm Animals, Vetsuisse Faculty, University of Zurich, Switzerland.
Ambulatory and Stationary Clinic, Vetsuisse Faculty, Department of Farm Animals, University of Zurich, Switzerland.
Theriogenology. 2016 Mar 15;85(5):986-998. doi: 10.1016/j.theriogenology.2015.11.010. Epub 2015 Nov 22.
The massive increase in size of the fetus and uterus in the last trimester is accompanied by an increasing demand for nutrients and oxygen, and it is assumed that this demand is met by increasing uterine and fetal perfusion. The goals of this study were to measure the perfusion of the uterine arteries and the placentomes in the last month of gestation and to investigate the effect of epidural anesthesia and isoxsuprine on perfusion. During the last month of gestation, eight Braunvieh cows underwent nine color Doppler sonographic examinations of the uterine arteries to determine diameter (DM), pulse rate (PR), resistance index, time-averaged maximum blood flow velocity (TAMV), and blood flow volume (BFV), and power-mode Doppler sonography was used to determine perfusion of placentomes. The PR increased (P < 0.001), and the BFV and TAMV of the ipsilateral uterine artery decreased between 4.5 and 0.5 weeks prepartum (BFV, 236.8 ± 65.80 and 208 ± 41.52 cm(3)/s, P < 0.01; TAMV, 140.0 ± 26.53 cm/s and 125.2 ± 18.46 cm/s, P < 0.05). After sonographic examination, the cows received epidural administration of local anesthetic (100-mg lidocaine) in the sacrococcygeal space or isoxsuprine (200 mg/cow, iv), and the sonographic measurements were repeated 30 minutes later. After epidural anesthesia, the TAMV and BFV of the contralateral uterine artery increased by 5.4% (P < 0.05) and 7.9% (P < 0.01). In the placentomes of the gravid uterine horn, the relative placentome perfusion and the color pixel grading (Cp) increased by 10.1% (P < 0.05) and 11.5% (P < 0.01) after epidural anesthesia. After isoxsuprine, the DM, PR, and BFV increased by 4.7%, 49.3%, and 16.9% in the ipsilateral uterine artery and by 10.8%, 48.7%, and 22.8%, respectively in the contralateral uterine artery. The TAMV of the ipsilateral uterine artery increased by 7.1% (P < 0.01), and the resistance index decreased in both uterine arteries (ipsilateral 24.2%, contralateral 14.9%, both P < 0.00001). Isoxsuprine increased the relative placentome perfusion and the Cp of the placentomes by 18.1% and 18.3% in the gravid horn and by 10.2% and 24.2% in the nongravid horn. Blood flow variables changed little in the last month of gestation. However, epidural anesthesia and isoxsuprine caused changes in uterine and placentome perfusion that suggest improvement of placental nutrient and oxygen supply to the fetus.
妊娠晚期胎儿和子宫体积的大幅增加伴随着对营养物质和氧气需求的增加，据推测，这种需求通过增加子宫和胎儿的灌注来满足。本研究的目的是测量妊娠最后一个月子宫动脉和胎盘的灌注情况，并研究硬膜外麻醉和异克舒令对灌注的影响。在妊娠最后一个月，对8头布劳恩维牛的子宫动脉进行了9次彩色多普勒超声检查，以确定直径（DM）、脉搏率（PR）、阻力指数、时间平均最大血流速度（TAMV）和血流量（BFV），并使用功率模式多普勒超声检查来确定胎盘的灌注情况。产前4.5至0.5周期间，同侧子宫动脉的PR增加（P < 0.001），BFV和TAMV降低（BFV，236.8±65.80和208±41.52 cm³/s，P < 0.01；TAMV，140.0±26.53 cm/s和125.2±18.46 cm/s，P < 0.05）。超声检查后，母牛在骶尾间隙接受硬膜外注射局部麻醉剂（100 mg利多卡因）或异克舒令（200 mg/头，静脉注射），30分钟后重复超声测量。硬膜外麻醉后，对侧子宫动脉的TAMV和BFV分别增加了5.4%（P < 0.05）和7.9%（P < 0.01）。在妊娠子宫角的胎盘中，硬膜外麻醉后相对胎盘灌注和彩色像素分级（Cp）分别增加了10.1%（P < 0.05）和11.5%（P < 0.01）。注射异克舒令后，同侧子宫动脉的DM、PR和BFV分别增加了4.7%、49.3%和16.9%，对侧子宫动脉分别增加了10.8%、48.7%和22.8%。同侧子宫动脉的TAMV增加了7.1%（P < 0.01），两条子宫动脉的阻力指数均降低（同侧24.2%，对侧14.9%，均P < 0.00001）。异克舒令使妊娠子宫角胎盘的相对胎盘灌注和Cp分别增加了18.1%和18.3%，非妊娠子宫角分别增加了10.2%和24.2%。妊娠最后一个月血流变量变化不大。然而，硬膜外麻醉和异克舒令引起了子宫和胎盘灌注的变化，提示胎盘向胎儿的营养物质和氧气供应得到改善。
