Risk of Acute Kidney Injury After Iodinated Contrast Media Exposure in Neonates in the ICU: Evaluation Using...

Background: Neonates' immature renal function may cause increased susceptibility to renal toxicity from iodinated contrast media (ICM). However, little high-quality evidence addresses acute kidney injury (AKI) risk after neonatal ICM exposure. Objective: To evaluate associations between ICM administration during CT and AKI risk in ICU-admitted neonates using contemporary neonatal AKI criteria and propensity-score analysis to address potential confounding factors. Methods: This retrospective study included neonates admitted to the ICU who underwent contrast-enhanced CT, noncontrast CT, or noncontrast MRI between June 2000 and June 2023. Examinations were stratified into ICM and control groups. AKI was defined based on contemporary neonatal-specific criteria as an increase in serum creatinine of ≥0.3 mg/dL within 48 hours relative to the examination's immediately preceding value or of ≥50% within 7 days relative to the lowest preexamination value since birth. AKI was classified as stage 1, 2, or 3, reflecting increasing severity. Two additional cohorts were formed to reduce confounding based on patient and examination characteristics: a propensity-score matching (PSM) cohort that contained reduced subsets of matched examinations and an overlap-weighted cohort that retained all examinations albeit with weighting reflecting covariate overlap. Associations between ICM exposure and AKI were assessed using logistic regression analyses. Results: The analysis included 1708 neonates (median age, 5 days; 987 male, 721 female) who underwent 1809 examinations. The ICM group included 1381 contrast-enhanced CT examinations; the control group included 428 noncontrast CT (n=41) or noncontrast MRI (n=387) examinations. The PSM cohort included 284 examinations per group. AKI incidence was significantly higher in the ICM group than in the control group in the original cohort (13.9% vs 8.2%; OR=1.83 [95% CI: 1.24-2.68]; P=.002), PSM cohort (12.3% vs 7.0%; OR=1.86 [95% CI: 1.03-3.36]; P=.04) and overlap-weighted cohort (12.8% vs 7.6%; OR=1.74 [95% CI: 1.05-2.86]; P=.03). Incidence of stage 2-3 AKI did not differ significantly between the ICM and control groups in any cohort. Conclusion: For neonates in the ICU, ICM exposure during CT was associated with increased risk of AKI, although not with stage 2-3 AKI. Clinical Impact: The analysis provide robust controlled evidence that neonatal ICM exposure increases AKI risk.