Onkar B Auti1, KV Manoj1, Vellaichamy M Annapandian2, DG Santosh Kumar1, K Murugan1, GA Karthik1, Venkatraman Bhat1, Vimal Raj1
1Department of Radiology, Narayana Health City, Bengaluru, Karnataka, India.
2Department of Academic Research, Narayana Hrudayalaya Foundations, Bengaluru, Karnataka, India.
Background: Serum creatinine (SC) levels are routinely obtained before administering intravenous contrast agents to assess the risk of developing contrast-induced nephropathy (CIN). We reviewed the renal profile of Indian patients attending our department to assess if SC levels are routinely required and the importance of calculating estimated glomerular filtration rate (eGFR). Materials and Methods: We prospectively analyzed 785 consecutive outpatients attending our department for cross-sectional examination. Multiple standard parameters were considered as risk factors for developing CIN. SC and eGFR values were obtained in patients sent for contrast examination. Results: A total of 234 (30%) patients were above 55 years of age; 122 (15.5%) had diabetes, of these 18 (15%) were on insulin. We found 167 (21.2%) patients with hypertension and 33 (4.2%) with known renal/cardiac diseases. Abnormal SC was found in 20 (3.9%) patients, and all these patients had at least one risk factor. No patient without any risk factor had abnormal SC. Based on eGFR, 204 (40%) patients had Stage 2, 46 (9%) patients had Stage 3, and 7 (1%) patients had Stage 4 renal dysfunction. Majority of patients (71%) with Stage 3 renal disease showed normal SC values. Only one patient under the age of 50 years without any risk factors had Stage 3 renal disease. Conclusion: Hypertension, diabetes, and advanced age are common risk factors for CIN in Indian population. Majority of patients with Stage 3 renal dysfunction have normal SC. Based on the study, we recommend measurement of SC/eGFR before giving intravenous contrast only in patients over the age of 50 years or those with known risk factors for CIN.
Keywords: Chronic kidney disease, computed tomography, contrast-induced nephrotoxicity, estimated glomerular filtration rate, serum creatinine.