Incidence and risk factors of contrast-associated acute kidney injury in patients hospitalised after contrast-enhanced computed tomography in the Emergency Department

Background Since 1930 it has been accepted that intravenous injection of iodinated contrast agent as part of contrast-enhanced computed tomography (CE-CT) imaging can induce a contrast-associated acute kidney injury (CA-AKI). For the last 10 years, studies have investigated this iatrogenia. However, those works didn’t concern French population and particularly patient hospitalised after emergency department (ED) visit. This study assessed the CA-AKI incidence and factor risks in patients hospitalised after a CE-CT in ED. Material and Methods This was a monocentric retrospective study, conducted in a University Hospital ED (Beaujon Hospital) between 2019 and 2022. Patients over 16 years old who received a CE-CT and two serum creatinine dosages, one pre-CT and one post-CT (2 to 7 days later), were included. Risk factors and protective factors of CA-AKI as well as population characteristics were analysed. Results After studying 5079 enhanced CT-scans, 1463 patients fulfilled the inclusion criteria. The incidence of CA-AKI was 4.1%. The associated risk factors were: hypertension (adjusted odds ratio (aOR) = 3.36, 95% confidence interval (CI) (1.76–6.43)), CKD grade 4–5 (aOR = 5.89, 95% CI (1.39–24.95)), waiting time before CT (aOR = 3.36, 95% CI (1.76–6.43)). Ongoing treatment by metformin was found to be a protective factor (aOR = 0.26, 95% CI (0.06–1.12)). Conclusion It appeared that only hypertension and CKD grade 4–5 were risk factors for CA-AKI. Their absence would allow performing a CE-CT without waiting for kidney function levels. This consideration could reduce patient length of stay and the associated morbidity and mortality.