Predictive factors for contrast-induced acute kidney injury in high-risk patients given N-acetylcysteine prophylaxis

BACKGROUND: Contrast–induced acute kidney injury (CI-AKI) is recognized as a common complication of radiographic contrast-enhanced procedures. N-acetylcysteine (NAC) is commonly prescribed, but CI-AKI can still develop despite NAC administration as prophylaxis. OBJECTIVE: Identify the predictive factors for development of CI-AKI in patients prescribed NAC. DESIGN: Prospective, cross-sectional. SETTING: A tertiary hospital in Malaysia. PATIENTS AND METHODS: All adult patients who were prescribed NAC for prevention of CI-AKI were identified through an NAC drug usage monitoring card maintained by the inpatient pharmacy. The study was conducted from March to July 2017. MAIN OUTCOME MEASURES: Statistically significant predictive factors for development of CI-AKI despite NAC administration. SAMPLE SIZE: 152 RESULTS: The most commonly recognized risk factors for CI-AKI present in the study population were renal impairment (n=131, 86.2%), anemia (n=107, 70.4%), and diabetes mellitus (n=90, 59.2%). Hydration therapy was initiated in 128 patients (84.2%) prior to the contrast-enhanced procedure. Sixty-one (40.1%) were treated with nephrotoxic medications concomitantly with NAC. Fifteen (9.9%) patients developed AKI. Hypotension (OR: 6.02; 95% CI 1.25–28.97) and use of high contrast volume (OR: 6.56; 95% CI: 1.41–30.64) significantly increased the odds for AKI. Prior hydration therapy (OR: 0.13; 95% CI 0.03–0.59) showed protective effects. CONCLUSION: The risk predictors identified for CI-AKI were hypotension, high contrast volume and prior hydration therapy. LIMITATION: May not have identified other confounding factors for development of CI-AKI.