Williams K, MacLean C
University of British Columbia, Department of Obstetrics and Gynaecology, Vancouver, Canada.
J Perinat Med. 1994;22(4):291-4. doi: 10.1515/jpme.1994.22.4.291.
To compare the effect of a change in maternal posture on maternal cerebral blood flow velocity assessed transcranially in a normal vs a pre-eclamptic group 5 normotensive and 5 pre-eclamptic patients had maternal middle cerebral artery (MCA) blood flow velocity assessed in 2 positions supine and sitting upright using a 2 mHz transcranial doppler ultrasound. Comparison was then made of the effect of a change in posture on cerebral blood flow velocity in both groups using paired student-t test. Normotensive women showed minimal change in MCA blood flow velocity while pre-eclamptic women showed a 20% rise in all aspects of MCA blood flow velocity from supine to sitting. In pre-eclamptic patients MCA blood flow velocity which showed a significant rise with change in posture is not accompanied by significant changes in blood pressure and so is not a secondary response to a change in cardiac output by may be a primary effect related to local circulatory changes. Transcranial assessment of maternal cerebral blood flow velocity performed in normotensive and various hypertensive groups showed significant variation with change in posture in the pre-eclamptic group.
为比较正常组和先兆子痫组孕妇姿势改变对经颅评估的孕妇脑血流速度的影响，对5名血压正常的孕妇和5名先兆子痫孕妇，使用2兆赫经颅多普勒超声在仰卧位和直立坐位两个体位评估其大脑中动脉（MCA）血流速度。然后采用配对学生t检验比较两组姿势改变对脑血流速度的影响。血压正常的女性MCA血流速度变化极小，而先兆子痫女性从仰卧位到坐位时，MCA血流速度各方面均升高了20%。在先兆子痫患者中，MCA血流速度随姿势改变显著升高，但血压无显著变化，因此这并非心输出量变化的继发反应，可能是与局部循环变化相关的原发性效应。在血压正常组和各类高血压组中对孕妇脑血流速度进行的经颅评估显示，先兆子痫组中血流速度随姿势改变有显著变化。
