Williams K P, Wilson S
Department of Obstetrics and Gynaecology, Division of Maternal-Fetal Medicine, University of British Columbia, BC Women's Hospital, Vancouver, British Columbia, Canada.
Am J Obstet Gynecol. 1998 Nov;179(5):1200-3. doi: 10.1016/s0002-9378(98)70131-0.
Our purpose was to compare the estimated maternal cerebral perfusion pressure and an index of vascular resistance, the resistance area product, in nonpregnant women with hypertensive pregnant women.
The maternal middle cerebral artery was evaluated by transcranial Doppler ultrasonography in 17 nonpregnant women, 17 pregnant normotensive patients, 20 pregnant patients with chronic hypertension, and 21 pregnant patients with pre-eclampsia (defined by The American College of Obstetricians and Gynecologists criteria) and cerebral blood flow velocities were determined. We calculated estimated cerebral perfusion pressure as [Estimated cerebral perfusion pressure = V mean/(V mean = V diastolic) (Mean blood pressure - Diastolic blood pressure)] modified from Aaslid et al, 1986. Because the diameter of the vessels could not be measured directly, an index of resistance, the resistance area product, was calculated. Resistance area product = Mean blood pressure/mean velocity (Evans et al, 1988). We calculated an index of cerebral blood flow (Cerebral blood flow index) = Estimated cerebral perfusion pressure/resistance area product.
Women who were chronically hypertensive and those with pre-eclampsia showed a significant increase in estimated cerebral perfusion pressure and resistance area product compared with nonpregnant and pregnant normotensive women. An estimate of cerebral blood flow (cerebral blood flow index) in nonpregnant women showed that pregnancy resulted in a nonsignificant 18% increase in cerebral blood flow.
Women with chronic hypertension and pre-eclampsia behave similarly by demonstrating significant increases in cerebral perfusion pressure (estimated cerebral perfusion pressure) and cerebrovascular resistance (resistance area product) compared with normotensive and nonpregnant women. Pregnant patients have a minimal increase in cerebral blood flow (18%).
我们的目的是比较非妊娠高血压女性与妊娠高血压女性的估计母体脑灌注压以及血管阻力指数即阻力面积乘积。
通过经颅多普勒超声对17名非妊娠女性、17名妊娠血压正常患者、20名妊娠慢性高血压患者以及21名妊娠子痫前期患者（根据美国妇产科医师学会标准定义）的母体大脑中动脉进行评估，并测定脑血流速度。我们根据Aaslid等人1986年的方法修改计算估计脑灌注压为[估计脑灌注压 = 平均流速/（平均流速 = 舒张期末流速）×（平均血压 - 舒张压）]。由于无法直接测量血管直径，计算了阻力指数即阻力面积乘积。阻力面积乘积 = 平均血压/平均流速（Evans等人，1988年）。我们计算了脑血流指数 = 估计脑灌注压/阻力面积乘积。
与非妊娠和妊娠血压正常的女性相比，慢性高血压女性和子痫前期女性的估计脑灌注压和阻力面积乘积显著增加。非妊娠女性的脑血流估计值（脑血流指数）显示，妊娠使脑血流无显著增加，增幅为18%。
与血压正常和非妊娠女性相比，慢性高血压和子痫前期女性表现相似，脑灌注压（估计脑灌注压）和脑血管阻力（阻力面积乘积）均显著增加。妊娠患者的脑血流仅有微小增加（18%）。
