Cerebral Regional Oxygen Saturation and Serum Neuromarkers for the Prediction of Adverse Neurologic Outcome in Pediatric Cardiac Surgery

The aim of this study is to determine the utility of non-invasive bedside neuromonitoring, including cerebral regional oxygen saturation (rSO2) measured by near-infrared spectroscopy and serum biomarkers, in identifying children at risk from adverse neurological outcome after heart surgery. Prospective observational study including 39 consecutive children undergoing heart surgery with cardiopulmonary bypass (CPB) and normal neurologic exam prior to surgery. Cerebral rSO2 was measured at baseline (prior to surgery) and then continuously during surgery and for the first 16 h post-operatively. Neuromarkers [neuron-specific enolase (NSE), S100 beta, glial fibrillary acidic protein (GFAP), and brain-derived neurotrophic factor (BDNF)] were measured in serum at baseline, immediately after CPB and at 16 h post-operatively. Adverse neurological outcome was defined as an abnormal pediatric cerebral performance category (PCPC) scale score at 12 months after surgery. Sixteen children (41 %) had an abnormal PCPC scale score at the 12-month evaluation after surgery. In children with unfavorable neurological outcomes, mean cerebral rSO2 values were lower and the area-under-the-curve below a threshold of 40 and 20 % below baseline were also increased. No significant differences were found in serum neuromarkers between groups at the time points that were assessed. Bedside determination of cerebral rSO2 may have some utility in identifying children at risk for adverse neurological outcome after heart surgery in children. Additional studies that are sufficiently powered to control for the many covariates in this patient population will be required to fully interrogate this important question. The role of serum neuromarkers in the immediate post-operative period do not appear to be helpful in this question, though more thorough interrogation of delayed periods may ultimately demonstrate some utility in answering this question.