IV Contrast Administration for CT: A Survey of Practices for the Screening and Prevention of Contrast Nephropathy

Abstract

A wide variation of practice patterns is apparent in the screening and prevention of contrast nephropathy. In some cases, these patterns conflict with recommendations from the literature. The results of this study identify opportunities for further research and areas in need of improved practice guidelines.

Contrast Material–induced Nephrotoxicity and Intravenous Low-Osmolality Iodinated Contrast Material: Risk Stratification by Using Estimated Glomerular Filtration Rate

“…commonly used to assess nephrogenic systemic fibrosis risk before examinations enhanced with gadolinium-based contrast agents (11,24). We showed that IV LOCM is nephrotoxic in patients with stable pre-CT eGFR of less than 30 mL/min/1.73 m 2 , with a trend toward significance in patients with stable pre-CT eGFR of 30-44 mL/min/1.73 m 2 .…”

“…In recent years, retrospective studies have shown similar rates of post-CT acute kidney injury (AKI) in nonenhanced and contrast-enhanced CT populations (2,(5)(6)(7)(8)(9)(10), which led some to question the incidence of CIN in this setting and whether it occurs at all (3,4). This topic has considerable clinical relevance because concern for renal toxicity is a main reason to avoid IV contrast material in some patients (11)(12)(13)(14)(15). Nonuse of IV contrast material leads to impaired diagnostic ability in many situations, while liberal use of IV contrast material may result in renal compromise.…”

“…Patients were subdivided according to eGFR into four discrete ranges (60, 45-59, 30-44, and ,30 mL/min/1.73 m 2 ) by using a combination of published guidelines for chronic kidney disease (19) and published recommendations regarding nephrogenic systemic fibrosis risk stratification (12,24). These ranges of eGFR were chosen in part to allow a CT examination were derived and extrapolated from relevant publications and guidelines regarding CIN (11)(12)(13)(14)(15), cataloged for each patient, and incorporated into the propensity score analysis. Diagnoses and medications were derived from admission documentation, discharge documentation, and International Classification of Diseases (ICD)-9 code analysis that pertained to the emergency department or hospital visit associated with the index CT.…”

“…Because this was a retrospective study, the possibility of selection bias might exist between the control group and study group; we attempted to address this by using a propensity-matched multivariate model that accounted for a large number of known risk factors for CIN (11)(12)(13)(14)(15). As a result of this model, we confirmed that the nonenhanced CT population before matching was fundamentally different than the contrast-enhanced CT population with respect to likelihood of patients receiving contrast material.…”

Contrast Medium–induced Nephrotoxicity Risk Assessment in Adult Inpatients: A Comparison of Serum Creatinine Level– and Estimated Glomerular Filtration Rate–based Screening Methods

“…The ESUR guideline is supported by a large propensity-matched retrospective multivariate analysis of adult inpatients with stable renal function (20) that showed that IV iodinated contrast medium is a borderline nephrotoxic risk factor in patients with an eGFR of 30-44 mL/min/1.73 m 2 and is a substantial nephrotoxic risk factor in patients with an eGFR of lower than 30 mL/min/1.73 m 2 . The ESUR position is also supported by findings in other series (21)(22)(23)(24) that demonstrated that the incidence of post-computed tomographic (CT) acute kidney injury is highly correlated with increasing stage of chronic kidney disease, with those patients who have an eGFR of lower than 45 clinical landscape (3). In a 2006 survey of academic, private, and mixed radiology practices in the United States, Elicker et al (3) demonstrated that 92% (369 of 400) of all surveyed radiologists still used an SCr level-based threshold value to stratify CIN risk prior to inpatient examinations, while only 2% (eight of 400) used estimated creatinine clearance.…”