Intraoperative renal near-infrared spectroscopy indicates developing acute kidney injury in infants undergoing cardiac surgery with cardiopulmonary bypass: a case control study (Critical Care)

IntroductionAcute kidney injury (AKI) is a frequent complication after cardiac surgery with cardiopulmonary bypass in infants. Renal near-infrared spectroscopy (NIRS) evaluates regional oximetry in a non-invasive continuous real-time fashion, and reflects tissue perfusion. This study aimed to evaluate the relation between renal oximetry and development of AKI in the operative and post-operative setting in infants undergoing cardiopulmonary surgery. Methods: In this prospective study we enrolled 59 infants undergoing cardiopulmonary bypass surgery for congenital heart disease for uni-ventricular (n?=?26) or bi-ventricular (n?=?33) repair. Renal NIRS was continuously measured intraoperatively and at least 24?hours postoperatively, and analysed for the intraoperative and first 12, first 24 and following 24?hours periods. The renal oximetry values were correlated with the pediatric Risk-Injury-Failure-Loss-End (pRIFLE) classification for AKI, renal biomarkers and the postoperative course. Results: 28 (48%) infants developed AKI based on pRIFLE classification. Already in the intraoperative renal oximetry and further in the first 12, 24 and 48?hours postoperatively significantly lower renal oximetry values in AKI patients as compared to patients with normal renal function could be shown (P?