Glomerular filtration rate rather than Serum Creatinine should be used for recognizing patients at risk for development of Contrast induced nephropathy

Abstract

Objective: Serum Creatinine (SCr), widely used for renal function assessment is not an accurate measurement. SCr can be within normal range even when there is substantial nephropathy. The objective was to observe the incidence of contrast induced nephropathy (CIN) with normal SCr and low glomerular filtration rate (GFR).
Methodology: This was a cross-sectional, observational study involving patients undergoing coronary angioplasty. During a period of 6 months, 64 patients having SCr ? 1.4mg/dl and a GFR of < 80ml/min were selected who underwent elective coronary angioplasty. SCr was measured again after 48 hours of the procedure. CIN was defined as a > 25% increase in SCr from the pre-procedure level. For statistical analysis, SPSS version 10 was used to calculate one way Anova was used for comparing variables between CIN and No-CIN groups, while paired t-test was applied for comparison between pre and post procedure SCr.
Results: Out of 64 patients, CIN was seen in 14 patients (21.8%). After the procedure, significant difference was seen in the mean creatinine levels (p < 0.001). The before and after experiment creatinine values also showed a significant difference (p < 0.05).
Conclusions: SCr along with calculated GFR should be used to assess patients for underlying renal insufficiency undergoing contrast procedures like coronary angioplasty. Patients with low GFR and normal SCr have a significant risk of developing CIN. Identifying such patients before hand can help us decrease the overall incidence of CIN by administering timely prophylactic measures.