Contrast-Induced Nephropathy Following CT Scan and Its Associated Factors

Contrast-induced nephropathy (CIN) as a common complication of administration of contrast media (CM) is a major source of hospital morbidity and mortality. The aim of this study was to determine the incidence of CIN after contrast-enhanced CT scan and identifying the related risk factors.

A cross-sectional study was carried out in 100 patients attending Sari Imam Khomeini Hospital who underwent contrast-enhanced CT scan in 2016. Predictors of CIN were evaluated in four general categories, including demographic variables, underlying diseases, concomitant medications, and laboratory findings. Data were analyzed in SPSS V20.

In this study, increase in the concentration baseline serum creatinine of more than 25% or 0.5 mg/dl within 48 hours after the injection of contrast material was considered as an indicator of the incidence of CIN. Accordingly, the incidence rate was 7%. The incidence of CIN was significantly different in patients with and without hypertension (P= 0.028) and patients taking angiotensin II receptor blocking drugs (ARBs) (P= 0.019). Compared to creatinine, BUN and eGFR were both observed to be more accurate in predicting the incidence of CIN. BUN was found to have higher sensitivity and lower specificity while eGFR showed higher specificity and lower sensitivity.

In addition to hypertension and the use of ARBs as the major risk factors for the incidence of CIN, BUN was observed to be a better predictor for CIN than eGFR. Higher Efficacy of BUN could have been due to its larger size and therefore fewer laboratory errors.