Risk of acute kidney injury following repeated contrast exposure in trauma patients.

Purpose: This study investigates the risk of contrast-associated acute kidney injury (CA-AKI) in trauma patients, focusing on the impact of cumulative contrast medium doses.

Methods: A retrospective review was conducted at a level 1 trauma center (2019-2021). The study included patients who underwent intravascular contrast-enhanced examinations for torso trauma within 7 days post-injury. The total contrast medium volume within 7 days was calculated. Multivariate logistic regression (MLR) identified AKI risk factors.

Results: Among the 264 patients, 7.2% (19/264) developed AKI, with 3.4% (9/264) classified as KDIGO stage 3. Approximately 42.8% of patients underwent at least two contrast-enhanced examinations. The mean total contrast medium given was 129.5mL (range 80-410 ml). Multiple logistic regression (MLR) analysis identified four independent risk factors for AKI: diabetes mellitus, initial eGFR < 30, use of inotropic agents, and contrast medium exposure. The odds ratio of AKI increased by 2.92 (95% CI 1.30-6.53) for every 100 ml increase in contrast dose. The contrast volume exposure only plays an important role in severe trauma patients (ISS ≥ 25). Moreover, when correlated with eGFR, the contrast medium exposure volume demonstrated better predictive ability for AKI with a best cut-off value of Contrast volume to eGFR ratio > 1.86.

Conclusion: While repetitive contrast-enhanced examinations are sometimes inevitable, they do come with costs. The CA-AKI risk increases as the amount of contrast medium accumulates in trauma patients who require repetitive examinations.