Prognosis of critically ill patients with early and late sepsis-associated acute kidney injury: an observational study based on the MIMIC-IV.

Objective: The Acute Disease Quality Initiative (ADQI) working group recently released a consensus definition of sepsis-associated acute kidney injury (SA-AKI), but the prognosis and risk factors for early and late SA-AKI have not been studied.

Methods: This was a retrospective cohort study based on the Medical Information Mart for Intensive Care IV (MIMIC-IV) database (v2.2). First, SA-AKI patients that met the new definition from the ADQI were screened, and then, the relationships between SA-AKI occurrence time and relevant clinical parameters were analyzed.

Results: After propensity score matching, 1,090 early SA-AKI (AKI occurring within 48 h of sepsis diagnosis) cases and late SA-AKI (AKI occurring between 48 h and 7 days after sepsis diagnosis) cases were identified. Compared with late SA-AKI patients, early SA-AKI patients had no significant differences in all-cause mortality at 28 days, 60 days or 180 days, renal replacement therapy (RRT) rates; or major adverse kidney events at 30 days (MAKE-30). However, the renal recovery of early SA-AKI patients was significantly better than that of late SA-AKI patients, their lengths of hospital stay and intensive care unit stay were significantly shorter, and the number of patients with positive fluid balance was lower, but the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and nephrotoxic antibiotics and the incidence of septic shock were higher. In addition, there was a difference in the number of patients with early and late SA-AKI at highest AKI stages 1 and 3. Data analysis also revealed that liver disease, cancer, highest AKI stage 3 and septic shock were associated with renal nonrecovery.

Conclusions: Although there was no significant difference in mortality between early and late SA-AKI patients, there were significant differences in renal recovery, positive fluid balance, nephrotoxic antibiotic use, septic shock and AKI stage. Therefore, the classification of early and late SA-AKI has certain scientific and rational validity, but whether the two have different clinical outcomes and pathogeneses requires further study.