Does Introduction of Normal Saline Tip the Electrolyte Balance in Preeclampsia? [33I

Abstract

INTRODUCTION: Due to a nationwide shortage of Ringer's lactate, normal saline became the intravenous fluid of choice at our institution in 5/2018. Recent studies have raised concern on safety of administration of normal saline in critically ill patients. We sought to evaluate the impact of normal saline on the outcomes of women with preeclampsia receiving magnesium sulfate. METHODS: Prospective observational study of women with preeclampsia with severe features receiving normal saline. The amount of normal saline administered was calculated and a basic metabolic panel was surveyed approximately 12 hours after initiation of magnesium sulfate prophylaxis. Laboratory analytes were examined according to the amount of intravenous fluid received. RESULTS: From 5/2018 to 7/2018, a total of 124 patients were identified. The mean intravenous fluid volume received was 1.84 ± 0.9 L. Serum creatinine and chloride levels remained unchanged over time and across quartiles of amount of fluid received (p=0.322 and p=0.822, respectively). Incidentally, a significant relationship was found between calcium levels and both the amount of normal saline received (p=0.0003) and concurrent magnesium levels (p<.0001). When testing for interaction between calcium, magnesium, and normal saline, both of the latter contributed to an increased risk of hypocalcemia. CONCLUSION: There does not appear to be a significant consequence to either chloride levels or renal function when utilizing normal saline in women with preeclampsia receiving magnesium sulfate. Coincidentally, calcium levels significantly declined as the amount of intravenous fluid increased, which given the association with magnesium levels is suspected to be a function of magnesium sulfate exposure.