Authors :
Presenting Author: Evelina Dedic, DO – Nicklaus Children's Hospital
Najveen Alvi, MD – Fellow, Pediatric Cardiology, Nicklaus Children's Hospital; Jenna Schermerhorn, DO – Fellow, Pediatric Cardiology, Nicklaus Children's Hospital; Bhavi Patel, DO – Attending, Pediatric Cardiology, Nicklaus Children's Hospital; Anuj Jayakar, MD – Attending, Pediatric Neurology, Nicklaus Children's Hospital
Rationale:
The American Clinical Neurophysiology Society (ACNS) recommends 24 hours of electroencephalography (EEG) monitoring for neonates at high risk for seizures, including those with congenital heart defects (CHD) undergoing cardiopulmonary bypass (CPB). Reduced oxygenation during CPB can lead to seizures and impact neurological outcomes. Given continued postoperative sedation and paralysis, many seizures may be subclinical, placing value in EEG for detection of electrographic seizures to allow for timely treatment and decrease morbidity. As a Quality Improvement measure, we implemented postoperative video EEG surveillance in neonates undergoing CPB to improve seizure detection and timely treatment, with consideration of associated risk factors and neurological outcomes.
Methods:
We identified neonates less than one month of age undergoing CPB and implemented postoperative video EEG surveillance. The study occurred from June 2022 to May 2023, with inclusion of only the first procedure if more than one occurred. Data collected by chart review included patient characteristics, underlying CHD, preoperative workup, intraoperative measures, presence of postoperative seizure, antiepileptic (AED) use, EEG findings, and neuroimaging when applicable. EEG recordings were interpreted by trained epileptologists using standard ACNS terminology. Patients requiring AED received either phenobarbital, levetiracetam, or both, based on neurologist discretion.
Results:
Our study consisted of 41 neonates who underwent CPB with subsequent EEG monitoring. Video EEG was initiated within three hours postoperatively and detected seizures in 17.07% (n=7), with 2.44% (n=1) showing epileptiform discharges. Seizure onset ranged from 0.23-49 hours, with median time of 12 hours. Average time to AED initiation was 3.71 hours. Higher average bypass time was seen with seizures (244.86 min) than without (190.62 min). Additionally, 42.86% (n=3) with seizures showed either none or mild encephalopathy, with 57.14% (n=4) showing moderate-severe encephalopathy. Those without seizure had similar findings, 32.35% (n=11) had none or mild encephalopathy, and 67.65% (n=23) had moderate-severe encephalopathy. All with seizures had abnormal MRIs, with only two of seven having preoperative head ultrasound abnormalities.
Conclusions:
We identified seizures in 17.07% of neonates and on average achieved AED administration within 3.71 hours. Those with and without seizures showed similar encephalopathy severity. All with seizures showed abnormalities on MRI, but the long-term significance of this is uncertain given the need for longer follow-up. Our Quality Improvement measure is significant in that we identified higher average bypass times in those with seizures, suggesting CPB is a risk factor for seizures, an outcome that has led to postoperative video EEG monitoring in this population to become standard of care at our institution.
Funding: No sources of funding to report.