Association between early, small creatinine elevation and severe acute kidney injury in critically ill adult patients

Abstract

Background: Early prediction of AKI is crucial for critically ill patients. We investigated the association between small increase in creatinine and subsequent severe AKI in ICU patients.

Methods: We conducted this retrospective cohort with a multi-institutional database between 2007 and 2019. We included adult patients admitted to the ICU with creatinine changes that did not meet the criteria for AKI diagnosis within 48 h of ICU admission. The outcomes were stage 2 or 3 AKI, kidney replacement therapy, and mortality.

Results: We identified 44,805 patients and divided them into 3 groups by baseline creatinine levels: <1 mg/dL, 1 to 2 mg/dL, and ≥ 2 mg/dL. Compared with patients with higher baseline creatinine levels, patients with normal baseline creatinine levels had fewer comorbidities and less severe condition at ICU admission. The odds ratios of their outcomes increased exponentially with creatinine elevation within the first 48 h of ICU admission. The increasing odds ratios were more prominent in patients with normal baseline creatinine (P for interaction <0.001).

Conclusion: Small creatinine elevation within the first 48 h of ICU admission was strongly associated with the AKI, kidney replacement therapy, and death. This association was more prominent in patients with normal baseline creatinine.

Keywords: Absolute creatinine change; Acute kidney injury; Delta creatinine; Dialysis; Mortality.