(1450) Sodium Balance and Clinical Outcomes in Hyponatremic Patients Receiving Custom Dilution CRRT Fluids

Introduction: Rapid or over correction of serum sodium in an intensive care unit patient can lead to devastating patient outcomes, such as osmotic demyelination syndrome (ODS). Hyponatremic patients requiring continuous renal replacement therapy (CRRT) are high risk of rapid sodium correction due to the standard 140mEq/L sodium chloride concentration in the fluids. Our institution instituted a collaborative protocol between nephrology and pharmacy to create custom CRRT dilution solutions for patients at risk of ODS.

Methods: This is a retrospective cohort study evaluating the effectiveness of the hyponatremia protocol on serum sodium changes in the first 24h and 48h of CRRT therapy. Adult and pediatric patients (18+) admitted to an ICU at the University of Kentucky from 2021 to 2023 were identified by having received the protocol orders, with a nadir serum sodium of < 120mEq/L. Comparator patients were identified throughout the same timeframe with a nadir serum sodium < 120mEq/L, who did not receive the custom dilution fluids for CRRT. The primary study outcome is the change in serum sodium from baseline to the 24h change, neurologic changes at 48h, and in-hospital mortality.

Results: A total of 18 patients were evaluated: 9 received the custom dilution solutions (protocol), 9 received standard CRRT solutions (non-protocol). The baseline serum sodium was not different between the two cohorts: protocol 117mEq/L (114-118) vs non-protocol 117mEq/L (114-118), p=0.94. The serum sodium at 24h was significantly lower in the protocol group: 122mEq/L (121-125) vs 130mEq/L (128-132), p= 0.046 and lower at 48h: 123mEq/L (121-131) vs 135mEq/L (129- 138), p=0.05. Non-protocol patients were more likely to have a neurologic symptom at 48h (44% vs 1%), p=0.114. In hospital mortality was similar (56% both groups).

Conclusions: In this small cohort study, treatment with custom dilution CRRT fluids was associated with a slower sodium correction, and lower likelihood of neurologic symptoms versus standard CRRT fluids. Further validation should be done with a larger cohort.