The association between increasing fluid balance, acute kidney injury and mortality in patients with sepsis and septic shock: A retrospective single center audit

Abstract

Purpose: To determine whether a positive fluid balance is associated with AKI and mortality in sepsis and septic shock patients.

Methods: A retrospective chart review of 482 patients treated for sepsis or septic shock. Patients were stratified according to quartiles of cumulative fluid balance on days 1 and 3. Logistic models were built to explore the association between fluid balance, AKI, and ICU mortality.

Results: During the first days of ICU admission, fluid input did not differ between survivors and non-survivors, yet a significant difference in output resulted in a more positive fluid balance in non-survivors on day 1 (37.24 ± 31.98 ml/kg vs. 24.97 ± 23.76 ml/kg, p < 0.001) and day 3 (83.33 ± 70.86 ml/kg vs. 62.20 ± 45.90 ml/kg, P = 0.005). Using a logistic regression model, a positive fluid balance on day three was independently associated with higher ICU mortality (odds ratio 1.007 for every one ml/kg, P = 0038) and AKIN stage III (odds ratio 1.006 for every one ml/kg, p = 0.031).

Conclusion: In patients with sepsis and septic shock, a more positive fluid balance is associated with an increased incidence of acute kidney injury and death after correction for possible confounders.

Keywords: Fluid output; Fluid therapy; ICU mortality; Multivariate analysis; Outcome; Sepsis; Septic shock.