Cerebrospinal fluid levels of magnesium in preeclampsia patients treated with magnesium sulfate and magnesium asphatate HCL, a preliminary report

Background: The incidence of preeclampsia seizure is low after parenteral magnesium sulfate therapy.

Setting: A Tertiary University Teaching Hospital in Lagos, Nigeria.

Design: A Retrospective Study.

Aim: To correlate magnesium levels of serum with those of cerebrospinal fluid in patients with preeclampsia treated with magnesium sulfate and magnesium asphatateHCl and to determine whether magnesium iron crosses the blood brain barrier significantly.

Methods and Material: A total of 48 patients in whom spinal anesthesia was used for delivery, 30 patients with preeclampsia with therapeutic serum levels made up the study group (17 used magnesium sulfate, 13 used magnesium asphatate (HCl) and 18 termed untreated normotensive gravid women served as control.

At the time of spinal anesthesia, about 1 ml aliquot of cerebrospinal fluid was obtained from each patient. The magnesium level was assayed using ASP. For statistical analysis, the student (t) test was used.

Results: The mean cerebrospinal fluid magnesium level for control group was 2.48 ± 0.21 mg/dl (ranged 2.1 – 2.9 mg/dl). For the preeclampsia group treated with magnesium sulfate, the mean cerebrospinal fluid magnesium level was 3.21 ± 0.41 mg/dl (range 2.3 – 3.4 mg/dl) and in magnesium asphatateHCl group. 3.36 ± 0.09 mg/dl (range 2.7 – 3.8 mg/dl).

Conclusion: This study shows that a small significant amount of magnesium crosses the blood brain barrier after magnesium treatment, which is higher than magnesium sulfate. More studies are needed to prove this.