Incidence and Risk Factors of Contrast-Induced Nephropathy in Emergency Department Patients Undergoing Contrast-Enhanced CT

Contrast-induced nephropathy (CIN) is a serious complication following the administration of iodinated contrast media, contributing significantly to hospital-acquired acute kidney injury. Contrast-induced nephropathy is defined as either a ≥25% increase from baseline creatinine levels or an absolute increase >0.5 mg/dL, within 48–72 hours after contrast media administration. This study evaluated CIN incidence and associated risk factors in emergency department (ED) patients undergoing contrast-enhanced CT. A prospective observational study was conducted at a tertiary-care ED (June 2013–September 2014). Adults (≥18 years) undergoing CT were enrolled, excluding those with baseline creatinine >1.2 mg/dL, acute kidney injury, or hemodynamic instability. Of the contrast-enhanced CT group (n=171), 14 patients (8.1%) developed CIN, whereas in the non-contrast CT group (n=171), 12 patients (7.0%) developed nephropathy. Hospitalization (p=0.030), advanced age (p=0.026), anemia (p=0.045), leukocytosis (p=0.005), and reduced GFR (p=0.028) were identified as risk factors for contrast-induced nephropathy. In the non-contrast group, anemia (p=0.003), hospitalization (n=9; p=0.039), and leukocytosis (p=0.007) were identified as risk factors for nephropathy. No cases of nephropathy was observed in patients discharged from the ED in either group. Contrast media did not significantly increase nephropathy risk in ED patients with normal renal function. However, older age, anemia, and hospitalization identified high-risk subgroups. Prophylactic measures showed no clear benefit, possibly due to ED time constraints. Vigilance is recommended for elderly and hospitalized patients, with renal monitoring following contrast administration.