Association Between Base Excess and Mortality Among Patients in ICU with Acute Kidney Injury
Abstract Objective This study aimed to explore the association between base excess (BE) and risk of 30-day mortality among patients with acute kidney injury (AKI) in ICU.Methods This retrospective study including ICU patients with AKI from Medical Information Mart for Intensive Care (MIMIC)-IV database. We used multivariate Cox proportional-hazards model to calculate the hazard ratio (HR) for risk of 30-day mortality among patients with AKI. Furthermore, we utilized Cox proportional-hazard model with restrict cubic splines (RCS) to explore the potential no-linear association. Results Of all the 14238 ICU patients with AKI, BE showed U-shaped relationship with risk of 30-day mortality for patients with AKI, and higher or lower BE value could increase the risk. Compared with normal base excess (-3~3 mmol/L), patients with difference groups (BE ≤ -9mmol/L, -9 mmol/L <BE≤-3 mmol/L, 3 mmol/L <BE≤9 mmol/L and BE>9 mmol/L) had different HR for mortality: 1.57(1.40,1.76), 1.26(1.14,1.39), 0.97(0.83,1.12), 1.53(1.17,2.02) respectively. And the RCS analyses also showed U-shaped curve between BE and 30-day mortality risk.Conclusion Our results suggest both higher and lower BE in patients with AKI would increase the risk of 30-day mortality. BE measured at administration could be a critical prognostic indicator for ICU patients with AIK and provide guidance for clinicians.