P0582MAGNESIUM TREATMENT IN PREECLAMPSIA SHOULD BE TARGETED TO SERIC LEVELS TO AVOID TOXICITY
Authors: Santos Afonso , Cacheira Eunice , Coelho Sílvia , Telles Freitas Paulo 
Published: June 2020

Abstract

Background and Aims
Preeclampsia is potentially serious complication of pregnacy and frequently requires admission in ICU. Management of this condition involves treatment with magnesium sulfate to prevent progression to eclampsia or even more adverse outcomes such as maternal or fetal death. However the exact dose of magnesium needed is still to be determined and few studies have analyzed the impact of this therapheutic intervention in women admitted in intensive care units, in terms of outcomes and adverse effects. Herein, we present a series of patients diagnosed with preeclampsia, including its most severe presentations with eclampsia or HELLP syndrome, admitted in an intensive care unit.

Method
Demographic, clinical and laboratorial data of women admitted between January-2016 and December-2018 to the Polyvalent Intensive Care Unit (ICU) of Hospital Fernando Fonseca, a tertiary Hospital in Portugal, with the diagnosis of preeclampsia, were retrospectively collected. Diagnosis of preeclampsia, HELLP syndrome and eclampsia were performed according to the ISSHP criteria (2004). Acute Kidney Injury (AKI) was defined according to the KDIGO criteria. The study was approved by the Ethical Committee of the institution.

Results
42 patients were included, 52.3% (n=22) diagnosed as non-severe preeclampsia; 31% (n=13) as HELLP syndrome and 16.7% (n=7) as eclampsia. Mean age at presentation was 29.6±6.6 years old, with 52,4% (n=22) caucasian and 47.6% (n=20) black. Most patients were admitted in ICU in post-partum period, after cesarian delivery in 95.2% (n=40). Seven patients (16.7%) had a previous diagnosis of hypertension; 11.9% (n=5) were obese; none has previous chronic kidney disease.
At presentation, most patients diagnosed with preeclampsia had three diagnostic criteria (28.6%, n=12), including hypertension. Renal dysfunction was found in 80.9% (n=34) of patients, with proteinuria &gt;200mg/dL in 69% (n=29) and AKI in 19% (n=8). Mean Hb of 11.1±2.1g/dL, with median platelet count of 126000/uL (IQR 72000-201500) and median LDH of 388mg/dL (IQR 240-773).
Pre-partum magnesium sulfate treatment was initiated in 78.6% (n=33) of patients, but only 2.4% (n=1) had previous magnesemia levels determination. During the stay in ICU, daily levels of seric magnesium levels were obtained, with the highest median values found at day one after admission. Adverse events related to hypermagnesemia (bradipnea) occurred in 50% (n=21) of patients. In six patients (14.3%), treatment was stopped because of high levels of magnesemia or adverse events. 14.3% (n=6) progressed to eclampsia and fetal death occured also in 14.3% (n=6). Maternal deaths did not occur.
By logistic binary regression we found out that weight was an independent risk factor for the development of the composite outcome of eclampsia or fetal death, when adjusted to age, race, AKI, hemoglobin, platelet count, ALT, LDH, serum albumin and proteinuria. (p=0.04). However, when Magnesium was included in the analysis, all variables lost significance. An association between SOFA and SAPS scores and the occurrence of the composite outcome has been found (p= 0.03 and p=0.019, respectively).

Conclusion
Most patients with preeclampsia received treatment with magnesium sulfate without previous measurement of serum levels. Bradipnea occurred in 50% of cases and treatment had to be stooped in almost 15%. Nevertheless, magnesium levels were not independently associated with the composite outcome of fetal death or eclampsia. Future studies should evaluate if a dose adjusted to a specific target of magnesium seric level could be associated with less adverse effects while still reducing the risk associated with preeclampsia.