Neuromonitoring Modalities in Pediatric Cardiac Anesthesia: A Review of the Literature

Recent decades have witnessed incredible developments in the care of children with congenital heart disease (CHD), such that survival into adulthood is the expected outcome. Improved survival has shifted the focus from improvements in mortality to improvements in morbidity, with long-term neurologic sequelae among the most important. Children with CHD who undergo corrective procedures in infancy and early childhood have a high rate of neurodevelopmental disability later in childhood. Impaired neurocognition is a result of many factors, including prenatal brain injury; preoperative hemodynamic derangements; exposure to anesthetic drugs; and the abnormal physiological states associated with cardiopulmonary bypass, low-flow perfusion, and deep hypothermic circulatory arrest. The intraoperative period presents a challenge to the anesthesiologist because this is a vulnerable period for the neurologic system. Transcranial Doppler ultrasound, electroencephalography, near-infrared spectroscopy, and processed electroencephalography are the neuromonitoring modalities that may be used intraoperatively. Even though each modality has merits, no single modality is able to reliably guide changes to management that improve neurologic outcomes. The best strategy is likely a multimodal neurologic monitoring strategy, although the combination of monitoring may depend on local resources and patient risk factors. This review provides a brief overview of the current knowledge regarding neurodevelopmental outcomes in children with CHD and summarizes the evidence for the use of the following 4 neuromonitoring modalities: transcranial Doppler, cerebral near-infrared spectroscopy, standard electroencephalography, and processed electroencephalography.