///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Management of magnesium infusions at urgent intrapartum cesarean delivery: continue or stop?

Abstract Number: F3B-51
Abstract Type: Original Research

Hans P Sviggum M.D.1 ; Kjerstin Anderson Hoff RN, MS2; Lindsay Hunter Guevara MD3

Magnesium sulfate is the drug of choice for prevention of eclampsia. Although its administration has been found to significantly reduce the risk of eclampsia, there is uncertainty about the extent of that risk reduction as well as the level of severity of preeclampsia that warrants its use. The American College of Obstetricians and Gynecologists recently published an update to the guidelines on managing hypertension in pregnancy with the recommendation “for women with preeclampsia undergoing cesarean delivery, the continued administration of parenteral magnesium to prevent eclampsia is recommended”. No specific source is cited to support this recommendation. A document published by the Anesthesia Patient Safety Foundation in 2015 states that the magnesium infusion should be discontinued on transit to the operating room for an emergency cesarean delivery. It states further that the infusion can be restarted in the operating room for women for severe preeclampsia, and that it is useful to verify the infusion pump programming with the labor and delivery nurse prior to restarting. The primary aim of this study was to identify if there is a difference in the incidence of seizures in preeclamptic patients whose magnesium infusions are continued versus discontinued during cesarean delivery.

This retrospective cohort study included all women 18 years of age or greater over a ten-year period (2006-2015) who were treated with magnesium for preeclampsia and underwent cesarean delivery. Group 1 consisted of patients who had magnesium continued throughout the entire delivery period. Group 2 consisted of patients who had magnesium discontinued at cesarean delivery and restarted after the procedure. Group 3 consisted of patients who had the magnesium discontinued and then restarted in the operating room before conclusion of the procedure.

A total of 280 patients (Group 1, n=169; Group 2, n=91; Group 3, n=20) were included for analysis. No patient in any group experienced a seizure within 24 hours of cesarean delivery. There were no differences between groups in estimated blood loss (p=0.803), blood transfusion (p=0.606), ICU admission (p=0.168), postoperative ventiliatory support (p=0.138), or need for calcium administration.

Although under powered given the rarity of eclampsia, this study found no evidence that discontinuing magnesium at the time of cesarean delivery increases the risk of seizures. The half-life of magnesium is approximately four-to-five hours for a person with normal renal function; and therefore the expected decrease in the plasma concentration in a patient during a cesarean delivery would be small. Continuing a magnesium infusion during urgent cesarean delivery carries risk of drug error/overdose/toxicity. Therefore, our findings support the practice of discontinuing magnesium at urgent cesarean delivery until it can be safely and cautiously restarted. Certainly, if it can be restarted in the operating room, this should be the goal.

SOAP 2019