Effect of Magnesium on Glomerular Filtration Rate and Recovery of Hypertension in Women with Severe Preeclampsia.

INTRODUCTION: Magnesium sulfate is used for preventing seizures in patients with severe preeclampsia. Previous studies have demonstrated that magnesium plays a significant role in the endothelial function and might have clinically beneficial vasodilating properties.

OBJECTIVES: This study is aimed at evaluating the effect of magnesium sulfate on the glomerular filtration rate (GFR) during the first 24 h after delivery and during the duration of recovery from hypertension in preeclampsia.

METHODS: Severe preeclamptic patients who had normal serum creatinine levels (0.4-0.8 mg/dL) were included in the study. Twenty-three women with severe preeclampsia were divided into groups of 9, 8, and 6, and given 1.0, 1.5, and 2.0 g/h of magnesium sulfate, respectively. Magnesium sulfate infusion was used as seizure prophylaxis for 24 h after delivery. The cystatin C-based GFR was monitored for 24 h, and the blood pressure was recorded for 12 weeks postpartum.

RESULTS: Despite the minimal improvement of GFR 24-h after treatment initiation, survival analysis demonstrated a statistically significant relationship (log rank, p = 0.04) between magnesium dosage and recovery period from hypertension. The group receiving 2.0 g/h of magnesium experienced the shortest recovery period from hypertension (6.5 ± 1.8 days). Meanwhile, the other groups required 66.0 ± 26.9 and 48.3 ± 15.6 days to recover after 1.0 and 1.5 g/h of magnesium infusion, respectively.

CONCLUSION: Magnesium sulfate has no impact on GFR improvement during the first 24 h after delivery. However, magnesium maintenance infusion at 2.0 g/h is capable of preventing seizure by optimizing the therapeutic magnesium level (4.8-8.4 mg/dL) and shortening the hypertensive episode in preeclampsia.