Changes Of Uterine, Umbilical And Middle Cerebral Arteries Blood Flow By Magnesium Sulfate In Severe Preeclampsia

Objective:To evaluate Doppler parameters of uterine, umbilical and middle cerebral arteries before and after magnesium sulfate administration in pregnant women with severe preeclampsia, and provide a scientific basis for the treatment of severe preeclampsia.Methods:50women with severe preeclampsia and40normal pregnant women in July2010to February2011from affiliated hospital of JiNing medical college participated in the study. Mean maternal age was28.04±3.35years and mean gestational age was33.47±2.19weeks. All women had no essential hypertension, renal disease or cardiovascular and cerebrovascular diseases. There were no significant difference in the age and gestational weeks in the two groups.Doppler ultrasonography scans were performed before and48hours after intravenous administration of magnesium sulfate, no vasoactive drugs other than MgSO4were given. Maternal parameters such as heart rate, and systolic blood pressure, diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) were recorded. Application of color Doppler ultrasound techniques for the detection of uterine artery and umbilical artery peak systolic flow velocity and end diastolic velocity ratio (S/D), pulsatility index (PI) and resistance index (RI). The systolic peak velocity (Vs), the end of diastolic velocity (Vd), the mean velocity (Vm), PI and RI of the middle cerebral artery were measured by transcranial Doppler (TCD). According to the formula of perfusion pressure (CPP)=Vm/(Vm-Vd)](MAP-DBP), cerebral perfusion pressure (CPP).Results:1. It was not a significant difference between measurements of systolic pressure and diastolic pressure before and48hours after intravenous infusion of magnesium sulfate in the patients with severe preeclampsia (P>0.05). A statistically significant increase in mean maternal heart rate was found48hours after infusion of magnesium sulfate compared to severe pre-treatment measurements (P<0.05).2. Magnesium sulfate significantly reduced PI, RI and S/D ratio in uterine artery of the patients with severe preeclampsia (P<0.05).3. There were no significant changes in PI, RI, S/D ratio in umbilical artery of the patients with severe preeclampsia before and after administration of magnesium sulphate (P<0.05).4. There were no significant changes in PI, RI, S/D ratio and CPP of the middle cerebral artery before and after administration of magnesium sulphate (P>0.05).5. There were20patients with under perfusion,13patients with normal perfusion,17patients with over perfusion. Patients with over perfusion had a significant reduction in CPP after treatment, but patients with under perfusion and normal-perfusion had no significant changes in CPP after treatment.Conclusions:1. Maternal administration of intravenous magnesium sulfate in preeclampsia leads to an increase in maternal heart rate but had no influence on systolic and diastolic pressure.2. A reduction in the PI, RI and S/D ratio was recorded in uterine artery after treatment.3. Magnesium sulfate reduced CPP in patients with over perfusion.