Risk of Acute Kidney Injury Following Contrast-enhanced CT in Hospitalized Pediatric Patients: A Propensity Score Analysis

Background Acute kidney injury (AKI) remains a concern in hospitalized children undergoing CT with intravenous iodinated contrast material (ICM). Adult studies have shown frequencies of AKI after CT with intravenous ICM to be similar to propensity score-matched ICM-unexposed patient groups; similar data in pediatric patients are lacking. Purpose To evaluate the association between intravenous ICM exposure and AKI in hospitalized pediatric patients with stable kidney function undergoing contrast material-enhanced CT by comparing with a propensity score-matched ICM-unexposed patient sample undergoing abdominal US. Materials and Methods In this retrospective observational study, hospitalized patients aged 18 years or younger with stable kidney function and available serum creatinine (SCr) measurement before and after imaging who underwent CT with intravenous ICM or abdominal US (control group) between January 2009 and November 2018 were identified. The 1:1 propensity score matching was performed by using 23 covariates, stratified by estimated glomerular filtration rate (eGFR) before imaging (≥60 mL/min/1.73 m² or <60 mL/min/1.73 m²). AKI was defined by using Acute Kidney Injury Network SCr-related criteria. Multivariable logistic regression was performed to identify risk factors for AKI after imaging, including the effects of eGFR and intravenous ICM exposure before imaging. Results A total of 1850 unique patients were included in the propensity score-matched sample (925 exposed to ICM [mean age ± standard deviation, 8 years ± 6; 484 female patients]; 925 unexposed to ICM [mean age, 7 years ± 6; 484 female patients]). Frequency of AKI with eGFR greater than or equal to 60 mL/min/1.73 m² was 2.2% (20 of 889) for CT and US (odds ratio [OR]: 0.98; 95% confidence interval [CI]: 0.52, 1.86; adjusted P = .95) and with eGFR less than 60 mL/min/1.73 m² was 5.6% (two of 36) and 11.1% (four of 36) for CT and US, respectively (OR: 0.75; 95% CI: 0.11, 5.00; adjusted P = .76). Significant multivariable predictors of AKI included eGFR before imaging (OR: 0.99; 95% CI: 0.98, 0.995; P = .001), body mass index (OR: 1.06; 95% CI: 1.02, 1.10; P = .003), acquired kidney disease (OR: 1.95; 95% CI: 1.004, 3.78; P = .049), and nephrotoxic antibiotic exposure (OR: 2.86; 95% CI: 1.55, 5.25; P < .001). Intravenous ICM exposure was not predictive (OR: 0.91; 95% CI: 0.51, 1.64; P > .05). Conclusion Hospitalized children with stable kidney function who underwent CT with intravenous iodinated contrast material (ICM) had a similar frequency of acute kidney injury (AKI) compared with a propensity score-matched ICM-unexposed patient group. In pediatric inpatients with estimated glomerular filtration rate greater than or equal to 60 mL/min/1.73 m², ICM was not independently associated with AKI. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Paltiel in this issue.