Is contrast exposure safe among the highest risk trauma patients?

BACKGROUND: Despite improvements in the diagnosis and management of acute kidney injury (AKI), posttraumatic renal dysfunction continues to be associated with increased morbidity and mortality. Intravenous (IV) contrast is known to induce AKI in high-risk groups including the elderly and critically ill. We sought to determine whether IV contrast exposure among high-risk trauma patients resulted in renal dysfunction as defined by the Acute Kidney Injury Network criteria. METHODS: We performed a 3-year retrospective analysis of all patients admitted to our Level I trauma center surgical intensive care unit for >48 hours. Patients with preexisting chronic renal dysfunction were excluded. We performed univariate and bivariate analyses to identify risk factors for AKI. Multivariable logistic regression analysis identified independent predictors for AKI. Subgroup analysis was undertaken among high-risk groups to include elderly patients (aged ≥65 years) with admission hypotension (systolic blood pressure <90 mm Hg) and an Injury Severity Score (ISS) >25. RESULTS: Of the 6,317 patients, 571 (9.0%) patients met the inclusion criteria; 170 (29.8%) patients developed AKI. Age <65 years (odds ratio [OR] 2.26, 95%confidence interval [CI] = 1.06-4.80, p <0.034) and ISS >25 (OR 1.86, 95%CI = 1.12-3.07, p <0.015) were determined to be independent predictors of AKI. IV contrast was not identified to be a predictor of AKI. Upon subgroup analysis, IV contrast exposure was not a predictor of AKI among the elderly, hypotensive, or severely injured patients (ISS <25). CONCLUSION: A complete trauma workup including studies requiring IV contrast exposure should be considered safe even among high-risk trauma patients.