Urinary NGAL (Neutrophil Gelatinase Associated Lipocalin) as an Early Predictor of Acute Kidney Injury after Cardiac Surgeries

Background: Acute Kidney injury is one of the most common and serious complications that can develop after cardiac surgeries. Currently serum creatinine is the gold standard for detecting AKI. But various other studies have shown that there is a delay in rise in serum creatinine following renal injury thereby causing delay in early diagnosis and appropriate treatment. Aim: This study evaluates role of Urine NGAL (Neutrophil Gelatinase Associated Lipocalin) in diagnosing AKI early after cardiac surgeries. Materials & Methods: We prospectively enrolled 57 adult patients admitted for various cardiac surgeries over a period of 2 years from 2018 to 2020. Preoperative (0 hour) and postoperative (4 hour) urine NGAL was measured using an Enzyme linked immune sorbent assay. Mean of 0 hour and 4 hour uNGAL levels in AKI group was compared with that of non AKI group. Results: Among 57 patients, 6 (10.5%) patients developed AKI which was defined as rise in serum creatinine by 0.3 mg/dL within 7 days after the procedure. There was a significant rise in uNGAL levels in patients who developed AKI when compared to those who did not developed AKI. P value was <0.001 and the observations were statistically significant. ROC was generated and the AUC was 0.99. NGAL cutoff value was calculated as 0.2335 ng/ml for the prediction of AKI. All the 6 patients who developed AKI had 4 hour NGAL levels more than this cutoff. Conclusion: The results of this study suggest that urinary NGAL predicts AKI early after cardiac surgeries when compared to serum creatinine.