title: Non-invasive measurement of renal perfusion and oxygen metabolism to predict postoperative acute kidney injury in neonates and infants after cardiopulmonary bypass surgery.
abstract: BACKGROUND
  The pathophysiology of acute kidney injury (AKI) after cardiopulmonary bypass surgery for congenital heart disease is not completely understood. The aim of this study was to carry out a prospective analysis of the diagnostic value of non-invasive monitoring of renal oxygenation and microcirculation by combining laser Doppler flowmetry and tissue spectrometry.
  
  
  METHODS
  In 50 neonates and infants who underwent repair (n = 31) or neonatal palliation (n = 19) of congenital heart disease with cardiopulmonary bypass, renal oxygenation, and microcirculatory flow, the approximate renal metabolic rate of oxygen and Doppler-based renal resistive index were determined after surgery. Correlations between these parameters and the occurrence of AKI according to the Pediatric Risk, Injury, Failure, Loss, End Stage Renal Disease criteria were investigated.
  
  
  RESULTS
  Acute kidney injury occurred in 45% of patients after repair and in 32% after palliation. Renal oxygenation was significantly lower and the approximate renal metabolic rate of oxygen significantly higher in patients with AKI (P < 0.05). The microcirculatory flow was significantly higher in patients with AKI after neonatal palliation (P < 0.05), whereas renal resistive index was significantly higher in patients with AKI after repair (P < 0.05). The sensitivity of renal oxygenation, metabolic rate of oxygen, microcirculation, and resistive index in predicting AKI was 78-80, 73-78, 64-83, and 71-74%, respectively, with a specificity of 63-65, 54-75, 64-78, and 46-74% (area under the curve: 0.73-0.75, 0.68-0.83, 0.52-0.68, and 0.60-0.75), respectively.
  
  
  CONCLUSIONS
  Monitoring of renal oxygen metabolism allows early prediction of AKI in infants after cardiac surgery. In contrast, renal resistive index does not allow prediction of AKI after neonatal palliation with aortopulmonary shunt establishment.
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany felix.neunhoeffer@med.uni-tuebingen.de.
authors: F
authors: F
authors: Neunhoeffer
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: M
authors: M
authors: Wiest
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: K
authors: K
authors: Sandner
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: H
authors: H
authors: Renk
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: E
authors: E
authors: Heimberg
authors: Department of Thoracic and Cardiovascular Surgery, University Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: C
authors: C
authors: Haller
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: M
authors: M
authors: Kumpf
authors: Department of Thoracic and Cardiovascular Surgery, University Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: C
authors: C
authors: Schlensak
authors: Department of Paediatric Cardiology, Pulmology and Paediatric Intensive Care Medicine, University Children's Hospital, Hoppe-Seyler-Straße 1, Tübingen 72076, Germany.
authors: M
authors: M
authors: Hofbeck
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000503:physiopathology; D002315:Cardiopulmonary Bypass; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology; D010100:Oxygen / Q000378:metabolism*; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D013057:Spectrum Analysis
chemical_list: D010100:Oxygen
keywords: acute kidney injury; cardiopulmonary bypass; congenital; effective; heart defect; infant; neonate; renal blood flow; renal circulation; thoracic surgery