Abstracts

Rationale: Neonates with congenital heart disease are at risk for neurologic complications during the post-operative period, with seizures occurring in 5% to 25%. Both clinical and subclinical seizures worsen global outcome in neonates with brain injury.  Due to the high rate of seizures, the American Clinical Neurophysiology Society (ACNS) recommends considering continuous electroencephalogram (CEEG) monitoring for all neonates after cardiac surgery. UCLA implemented a CEEG protocol to monitor for electroclinical and electrographic seizures in an attempt to stratify neurologic risk factors in neonates who underwent cardiopulmonary bypass, a high risk procedure during cardiac surgery. Methods: From October 2015 to April 2018, CEEG monitoring was implemented for all neonates <31 days of age (corrected gestational age <44 weeks) who underwent congenital heart surgery with intraoperative cardiac bypass. EEG monitoring was performed for 48 hours. Head ultrasounds were performed either prior or after surgery. Anti-seizure medications were chosen based on the clinical team’s preference.   Results: 63 out of 64 eligible patients (98.5%) were placed on CEEG monitoring. The majority were male (55.5%) full-term (85.7%) neonates with 42/63 (66.6%) patients requiring deep hypothermic circulatory arrest (DHCA) during the surgeries. Seizures were detected in only 2/63 (3.2%), with 1 patient in electrographic status epilepticus requiring levetiracetam, phenobarbital, and midazolam to eliminate seizures. All seizures were subclinical, thus only identifiable with CEEG monitoring. Both patients had severe complications: The first patient developed a large subdural hematoma and the second patient had a cardiac arrest intraoperatively requiring extracorporeal membrane oxygenation (ECMO) post-operatively. 4/63 patients  died post-operatively (none had seizures).  Conclusions: The 3.2% rate of seizures post-cardiac bypass in neonatal cardiac surgery seen is within the range of previous published data. Of note, 19% of patients received intraoperative benzodiazepines, which can decrease the frequency of seizures. 1 patient had subclinical status epilepticus, which is concerning as high seizure burdens have been associated with worse neurologic outcomes. Further recruitment is needed to help identify risk factors for seizures, leading to a cost-effective stratification strategy for those critical care centers that cannot perform CEEG monitoring on all eligible patients. Additional goals include measuring neurodevelopmental outcomes. Funding: None