Fractional sodium excretion and its relation to in-hospital morbidity and mortality in patients admitted with decompensated heart failure

Abstract

Introduction, aim: In general, failure to decrease the extracellular fluid volume despite liberal use of diuretics is often termed diuretic resistance. We aimed to correlate between urinary fractional sodium excretion as a marker of diuretic resistance in patients admitted with congestive heart failure and its impact on length of hospital stay together with in-hospital morbidity and mortality. Patients and methods: 46 decompensated heart failure patients were enrolled in this study. We decided that the urine sample from which we can calculate the FENa level will be a 24-hour sample in an attempt to decrease the variability of FENa levels. FENa=100×Na(urinary)×creatinine(plasma)/Na(plasma)×creatinine(urinary) Intravenous furosemide was started on admission either as a continuous infusion or shots. It was followed-up during the hospital stay for inhospital mortality and morbidity. Results: FENa results came out with a median value of 1.5% with minimum and maximum FENa results equal to 0.05% and 5.2%, respectively. The only three variables that contributed significantly to the prediction of hospital stay were Hb, LVEF, and FENa; with the latter variable showing the most significant relation. Conclusion, recommendation: FENa can be used upon patient’s admission to guide therapy of heart failure in an attempt to reduce the hospital stay.

Keywords

• Fractional sodium excretion
• Heart failure
• Diuretic resistance