Towards integrative neuromonitoring of the surgical newborn A systematic review

BACKGROUND The altered neurodevelopment of children operated on during the neonatal period might be due to peri-operative changes in the homeostasis of brain perfusion. Monitoring of vital signs is a standard of care, but it does not usually include monitoring of the brain. OBJECTIVES To evaluate methods of monitoring the brain that might be of value. We also wanted to clarify if there are specific risk factors that result in peri-operative changes and how this might be evaluated. DESIGN Systematic review. DATA SOURCES A structured literature search was performed in MEDLINE in Ovid, Embase, Cochrane CENTRAL, Web of Science and Google Scholar. ELIGIBILITY CRITERIA Studies in neonates who received peri-operative neuromonitoring were eligible for inclusion; studies on neurosurgical procedures or cardiac surgery with cardiopulmonary bypass and/or deep hypothermia cardiac arrest were excluded. RESULTS Nineteen of the 24 included studies, totalling 374 infants, reported the use of near-infrared spectroscopy. Baseline values of cerebral oxygenation greatly varied (mean 53 to 91%) and consequently, no coherent results were found. Two studies found a correlation between cerebral oxygenation and mean arterial blood pressure. Five studies, with in total 388 infants, used (amplitude-integrated) electro-encephalography to study peri-operative brain activity. Overall, the brain activity decreased during anaesthesia and epileptic activity was more frequent in the peri-operative phase. The association between intra-operative cerebral saturation or activity and neuro-imaging abnormalities and/or neurodevelopmental outcome was investigated in six studies, but no association was found. CONCLUSION Neuromonitoring with the techniques currently used will neither help our understanding of the altered neonatal pathophysiology, nor enable early detection of deviation from the norm. The modalities lack specificity and are not related to clinical (long-term) outcome or prognosis. Accordingly, we were unable to draw up a monitoring guideline.