Post-operative acute kidney injury is associated with a biomarker of acute brain injury after paediatric cardiac surgery

Introduction:Children with CHD who undergo cardiopulmonary bypass are at an increased risk of acute kidney injury. This study evaluated the association of end-organ specific injury plasma biomarkers for brain: glial fibrillary acidic protein and heart: Galectin 3, soluble suppression of tumorgenicity 2, and N-terminal pro b-type natriuretic peptide with acute kidney injury in children undergoing cardiopulmonary bypass.Materials and Methods:We enrolled consecutive children undergoing cardiac surgery with cardiopulmonary bypass. Blood samples were collected pre-bypass in the operating room and in the immediate post-operative period. Acute kidney injury was defined as a rise of serum creatinine ≥50% from pre-operative baseline within 7 days after surgery.Results:Overall, 162 children (mean age 4.05 years, sd 5.28 years) were enrolled. Post-operative acute kidney injury developed in 55 (34%) children. Post-operative plasma glial fibrillary acidic protein levels were significantly higher in patients with acute kidney injury (median 0.154 (inter-quartile range 0.059-0.31) ng/ml) compared to those without acute kidney injury (median 0.056 (inter-quartile range 0.001-0.125) ng/ml) (p = 0.043). After adjustment for age, weight, and The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery category, each natural log increase in post-operative glial fibrillary acidic protein was significantly associated with a higher risk for subsequent acute kidney injury (adjusted odds ratio glial fibrillary acidic protein 1.25; 95% confidence interval 1.01-1.59). Pre/post-operative levels of galectin 3, soluble suppression of tumorgenicity 2, and N-terminal pro b-type natriuretic peptide did not significantly differ between patients with and without acute kidney injury.Conclusions:Higher plasma glial fibrillary acidic protein levels measured in the immediate post-operative period were independently associated with subsequent acute kidney injury in children after cardiopulmonary bypass. Elevated glial fibrillary acidic protein likely reflects intraoperative brain injury which may occur in the context of acute kidney injury-associated end-organ dysfunction.