https://doi.org/10.1177/0267659120968377 Perfusion 1–7 © The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0267659120968377 journals.sagepub.com/home/prf Background The decline of renal function remains a frequent and serious perioperative complication in pediatric popula- tions with congenital heart disease undergoing correc- tive surgery with cardiopulmonary bypass (CPB). 1,2 The incidence of renal dysfunction ranges between 5% and 39%. 2–4 Acute Kidney Injury (AKI) remains a major problem after these procedures and is a major cause of death in this patient group. 4–6 AKI and cardiac surgery outcomes have been studied extensively in adult and pediatric patients. 2,7,8 They also have an impact in driv- ing the need for renal replacement therapy, increasing the length of in-hospital and intensive care unit stays, and in the development of chronic kidney disease in this susceptible population. 5 In the neonates, the diagnosis of AKI, particularly mild to moderate forms, is even more difficult. SCr levels in the first few days of life are typically elevated, as a reflection of maternal creatinine, and decline in the first weeks of life as glomerular filtration rate (GFR) steadily improves. Thus, mild to moderate decreases in Biomarkers as predictors of renal damage in neonates undergoing cardiac surgery Evelyn Borchert 1 , René de la Fuente 1 , Ana María Guzmán 2 , Katia González 1 , Augusto Rolle 1 , Karina Morales 3 , Rodrigo González 4 , Roberto Jalil 5 and Guillermo Lema 1 Abstract Background: Acute Kidney Injury is a complication in children with heart disease undergoing cardiac surgery with cardiopulmonary bypass. The aim of this study is to describe the behavior of KIM-1 (Kidney Injury Molecule) and NGAL (Neutrophil Gelatinase Associated Lipocalin) as early predictors of renal damage, comparing them with serum creatinine and creatinine clearance, in neonates undergoing cardiac surgery. Methods: Twenty-one (21) neonates, under 4 kg, with complex congenital heart diseases, RACHS-1 > 3, without preoperative renal failure, were studied. Serum creatinine and creatinine clearance were measured preoperatively and at 24, 48, 72, 96 hours postoperatively. Urinary samples of KIM-1(pg/ml) and NGAL (ng/ml) were collected after induction of anesthesia at 24 and 48 hours post-operatively. Results: nRIFLE criteria were used to divide cohorts in “NO AKI” (12 patients) and “AKI” (nine patients). In the AKI group, serum creatinine increased significantly and creatinine clearance decreased significantly at 24, 48, and 72 hours compared with their respective baseline values. There was no difference in KIM-1 and NGAL values between patients who developed AKI and those who did not at any measured time. Conclusions: The deterioration of renal function continues to be one of the most frequent complications in this population. In our study, biomarkers did not show any correlation with the appearance of AKI. It remains to be seen whether this behavior of the biomarkers is linked with the non-consistent release of these types of molecules in immature kidneys. It is likely that a larger panel of biomarkers together with other glomerular filtration rate assessment methods will provide more information about AKI diagnosis. Keywords AKI; biomarkers; congenital heart surgery; neonates; CPB 1 Anesthesia Division, Pontificia Universidad Catolica de Chile, Santiago, RM, Chile 2 Clinical Laboratory,Pontificia Universidad Catolica de Chile, Santiago, RM, Chile 3 Pediatric Intensive Care, Pontificia Universidad Catolica de Chile, Santiago, RM, Chile 4 Cardiovascular Surgery, Pontificia Universidad Catolica de Chile, Santiago, RM, Chile 5 Nephrology. Pontificia Universidad Catolica de Chile, Santiago, RM, Chile Corresponding author: Evelyn Borchert, Anesthesia Division, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago, RM 8330024, Chile. Email: evelynborchert@gmail.com 968377PRF 0 0 10.1177/0267659120968377PerfusionBorchert et al. research-article 2020 Original Paper