The effect of magnesium on coagulation in parturients with preeclampsia

Preeclampsia is associated with complex coagulation abnormalities that incl ude altered platelet function and consumption and activation of the fibrino lytic system. Magnesium sulfate, which is used as a therapeutic modality fo r the prevention of seizures in preeclamptic parturients, has anticoagulant and antiplatelet effects. We sought to determine the effects of magnesium on various components of the coagulation system in patients with preeclamps ia. We assessed the coagulation status of 18 parturients with preeclampsia being treated with magnesium. The assessment was performed with the thrombo elastograph test, which provides an overall assessment of blood coagulation via the coagulation index. Thromboelastography was performed before beginn ing magnesium therapy and 30 min and 2 h after a 6-g bolus of TV magnesium. The R value (time to first clot formation) was found to be significantly s lower (P < 0.05) at 30 min after the magnesium bolus. This result suggests increased coagulant factor activity resulting from the magnesium bolus. How ever, there was no effect of magnesium on the overall coagulation, as evide nced by the lack of change in the coagulation index either at 30 min or at 2 h after the completion of the initial magnesium bolus. Therefore, this th erapy should have no effect on the use of neuraxial techniques.