Early and delayed acute kidney injury after contrast-enhanced CT in critically ill adults: a target trial emulation.

PURPOSE: To assess whether intravenous iodinated contrast administered for computed tomography is associated with early or delayed acute kidney injury (AKI) in critically ill adults. METHODS: We conducted a retrospective target trial emulation using the Medical Information Mart for Intensive Care IV (MIMIC-IV), a single-center, deidentified electronic health record database of hospital and intensive care admissions. Adults undergoing contrast-enhanced CT (CECT) or non-contrast CT (NCCT) during or immediately before intensive care admission were included. The primary outcome was creatinine-defined AKI within 48 h. Inverse probability of treatment weighting (IPTW) addressed measured confounding. RESULTS: Among 7,772 patients, 5,319 underwent CECT and 2,453 underwent NCCT. AKI within 48 h occurred in 19.3% and 20.4%, respectively. CECT was not associated with AKI within 48-72 h, time to first AKI through 7 days, renal replacement therapy within 7 days, or longitudinal creatinine trajectories. CONCLUSION: CECT was not associated with early or cumulative 7-day creatinine-defined AKI in critically ill adults. Residual confounding remains possible, particularly because acute illness severity, imaging indication, and post-index events were incompletely captured.