Early Detection of Acute Kidney Injury by Neutrophil Gelatinase Associated Lipocalin in Patients Undergoing Coronary Artery Bypass Grafting with Cardiopulmonary Bypass.

Abstract

Neutrophil Gelatinase-Associated Lipocalin (NGAL) is rapidly released by renal tubules after injury, potentially allowing early identification of acute kidney injury (AKI) after cardiac surgery. However, the diagnostic performance of NGAL has varied widely in clinical studies and it remains unknown what factors modify the relationship between NGAL and AKI. The main objective of the study was to determine the efficacy of NGAL in early detection of AKI among the CABG patients undergoing cardiopulmonary bypass (CPB). This prospective observational study was conducted in the Department of Nephrology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh in collaboration with the Department of Biochemistry, BSMMU among 42 patients admitted into the Department of Cardiac Surgery, Ibrahim Cardiac Hospital and Research Institute, Dhaka Bangladesh from July 2014 to June 2015. For the measurement of NGAL, urine samples were obtained before surgery and 6 hours after commencement of CPB. Serum creatinine was measured preoperatively and 6, 24 and 48 hours postoperatively. Increase in the serum creatinine level at 6, 24 and 48 hours after surgery was used to analyze the diagnostic value of urinary NGAL. In this study 42 CABG patients with no known renal insufficiency planned to have CPB were included. Receiver-operator characteristic (ROC) was constructed by using NGAL, which gave a cut off value of ≥185.90ng/ml. Eight patients were AKI positive among them 6(75.0%) patients were NGAL positive and 2(25.0%) were NGAL negative. Diagnosis of AKI was delayed by 24-48 hours by serum creatinine measurement. This study has demonstrated that level of urinary NGAL concentration at 6 hours post CPB increased before the increase of serum creatinine level and NGAL is an early predictor of AKI in adult cardiac surgical patients. The early detection of renal injury by NGAL may allow earlier intervention in patients with high risk for AKI.