16 Serum magnesemia during maintenance dose of 1 g/h vs. 2 g/h of magnesium sulfate infusion for the prevention of eclampsia in women with severe preeclampsia: Randomized trial

Abstract

Objective Compare magnesemia during intravenous use of magnesium sulfate in the maintenance phase 1g/h versus 2g/h to prevent eclampsia in pregnant women with severe preeclampsia. Methods The authors conducted a randomized clinical trial, triple blind, in the Obstetric Intensive Care Unit (ICU) and Pre-birth of the Integrative Medicine Institute Prof. Fernando Figueira from December 2014 to June 2015. We included 62 patients with severe preeclampsia, which were randomized into two groups: MgSO 4 maintenance dose of 1g/h or 2g/h. The patients included were subjected to evaluation of magnesium serum concentration immediately after the start of maintenance, half-hour, in two hours the first six hours, and thereafter six hours up to 24h of magnesium sulfate. The Student t test, Mann–Whitney, Fisher's chi-square association Pearson and exact tests were used for statistical analysis. The p values were two-tailed and the significance level was 5%. Results Five patients undergoing 2g/h reached the level of blood magnesium four to 7mEq/L considered by previous study as therapeutic. In contrast, none of the patients randomized to the group of 1g/h reached that level. The frequency of side effects was significantly higher in the group of 2g/h compared to 1g/h (71.0% vs 41.9%), but were observed only mild adverse effects. Neonatal respiratory disorders were very common complications, but there was no statistically significant difference between groups (81.3% for the group of 2g/h×86.7% for the group of 1g/h) and, in most cases (90.6% for the group of 2g/h x 93.3% for the group of 1g/h), there was no need for neonatal resuscitation. Only one in each group progressed to neonatal death. Conclusion Magnesium sulfate therapy at a dose of 1g/h was equally effective and safer, since there were less side effects for the mother. No difference was observed in neonatal prognosis. Keywords: Preeclampsia; Dose; Magnesium sulfate; Magnesemia; Controlled clinical trials. Clinical trials registration: ClinicalTrials.gov: www.clinicaltrial.gov, NCT02396030.