Near-Infrared-Based Cerebral Oximetry for Prediction of Severe Acute Kidney Injury in Critically Ill Children After Cardiac Surgery

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Objectives: Cerebral oximetry by near-infrared spectroscopy is used frequently in critically ill children but guidelines on its use for decision making in the PICU are lacking. We investigated cerebral near-infrared spectroscopy oximetry in its ability to predict severe acute kidney injury after pediatric cardiac surgery and assessed its additional predictive value to routinely collected data. Design: Prospective observational study. The cerebral oximeter was blinded to clinicians. Setting: Twelve-bed tertiary PICU, University Hospitals Leuven, Belgium, between October 2012 and November 2015. Patients: Critically ill children with congenital heart disease, younger than 12 years old, were monitored with cerebral near-infrared spectroscopy oximetry from PICU admission until they were successfully weaned off mechanical ventilation. Interventions: None. Measurements and Main Results: The primary outcome was prediction of severe acute kidney injury 6 hours before its occurrence during the first week of intensive care. Near-infrared spectroscopy-derived predictors and routinely collected clinical data were compared and combined to assess added predictive value. Of the 156 children included in the analysis, 55 (35%) developed severe acute kidney injury. The most discriminant near-infrared spectroscopy-derived predictor was near-infrared spectroscopy variability (area under the receiver operating characteristic curve, 0.68; 95% CI, 0.67–0.68), but was outperformed by a clinical model including baseline serum creatinine, cyanotic cardiopathy pre-surgery, blood pressure, and heart frequency (area under the receiver operating characteristic curve, 0.75; 95% CI, 0.75–0.75; p < 0.001). Combining clinical and near-infrared spectroscopy information improved model performance (area under the receiver operating characteristic curve, 0.79; 95% CI, 0.79–0.80; p < 0.001). Conclusions: After pediatric cardiac surgery, near-infrared spectroscopy variability combined with clinical information improved discrimination for acute kidney injury. Future studies are required to identify whether supplementary, timely clinical interventions at the bedside, based on near-infrared spectroscopy variability analysis, could improve outcome.