Association between base excess and 28-day mortality in sepsis patients: A secondary analysis based on the MIMIC- IV database

OBJECTIVE: The relationship between base excess (BE) and 28-day death in sepsis patients remains to be elucidated. The aim of our clinical study is to explore the association of BE with 28-day mortality in patients with sepsis by using a large sample, multicenter Medical Information Mart for Intensive Care IV (MIMIC-IV) database. METHODS: We extracted the data of 35,010 patients with sepsis from the MIMIC-IV database, in which we used BE as an exposure variable and the 28-day mortality as an outcome variable, respectively, so as to explore the impact of BE on the 28-day mortality of patients with sepsis after adjusting for covariates. RESULTS: BE and the 28-day mortality of patients with sepsis appeared to have a U-shaped relationship. The calculated inflection points were −2.5 mEq/L and 1.9 mEq/L, respectively. Our data demonstrated that BE was negatively associated with 28-day mortality in the range of −41.0 mEq/L to −2.5 mEq/L (odds ratio: 0.95; 95% confidence intervals (95%CI): 0.93 to 0.96), p < 0.0001. When BE was in the range of 1.9 mEq/L to 55.5 mEq/L, however, a positive association existed between BE and 28-day mortality of patients with sepsis (odds ratio: 1.03; 95% CI: 1.00 to 1.05; p < 0.05). CONCLUSION: The BE levels have a U-shaped relationship with the 28-day mortality in patients with sepsis, in which the mortality of patients will gradually decrease with a BE value from −41.0 mEq/L to −2.5 mEq/L, while the mortality will increase with a BE value from 1.9 mEq/L to 55.5 mEq/L.