title: Subclinical seizures identified by postoperative electroencephalographic monitoring are common after neonatal cardiac surgery.
abstract: OBJECTIVE
  The American Clinical Neurophysiology Society recommends continuous electroencephalographic monitoring after neonatal cardiac surgery because seizures are common, often subclinical, and associated with worse neurocognitive outcomes. We performed a quality improvement project to monitor for postoperative seizures in neonates with congenital heart disease after surgery with cardiopulmonary bypass.
  
  
  METHODS
  We implemented routine continuous electroencephalographic monitoring and reviewed the results for an 18-month period. Clinical data were collected by chart review, and continuous electroencephalographic tracings were interpreted using standardized American Clinical Neurophysiology Society terminology. Electrographic seizures were classified as electroencephalogram-only or electroclinical seizures. Multiple logistic regression was used to assess associations between seizures and potential clinical and electroencephalogram predictors.
  
  
  RESULTS
  A total of 161 of 172 eligible neonates (94%) underwent continuous electroencephalographic monitoring. Electrographic seizures occurred in 13 neonates (8%) beginning at a median of 20 hours after return to the intensive care unit after surgery. Neonates with all types of congenital heart disease had seizures. Seizures were electroencephalogram only in 11 neonates (85%). Status epilepticus occurred in 8 neonates (62%). In separate multivariate models, delayed sternal closure or longer deep hypothermic circulatory arrest duration was associated with an increased risk for seizures. Mortality was higher among neonates with than without seizures (38% vs 3%, P < .001).
  
  
  CONCLUSIONS
  Continuous electroencephalographic monitoring identified seizures in 8% of neonates after cardiac surgery with cardiopulmonary bypass. The majority of seizures had no clinical correlate and would not have been otherwise identified. Seizure occurrence is a marker of greater illness severity and increased mortality. Further study is needed to determine whether seizure identification and management lead to improved outcomes.
authors.affiliation: Division of Cardiac Critical Care Medicine, Department of Anesthesiology, Critical Care Medicine, and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa. Electronic address: naim@email.chop.edu.
authors.forename: Maryam Y
authors.initials: MY
authors.lastname: Naim
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: J William
authors.initials: JW
authors.lastname: Gaynor
authors.affiliation: Division of Cardiac Critical Care Medicine, Department of Anesthesiology, Critical Care Medicine, and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Jodi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Division of Cardiothoracic Anesthesiology, Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Susan C
authors.initials: SC
authors.lastname: Nicolson
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fuller
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Spray
authors.affiliation: Division of Neurology, Departments of Neurology and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Dlugos
authors.affiliation: Division of Neurology, Departments of Neurology and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Clancy
authors.affiliation: Division of Neurology, Departments of Neurology and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Livia Vianez
authors.initials: LV
authors.lastname: Costa
authors.affiliation: Division of Neurology, Departments of Neurology and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Licht
authors.affiliation: Department of Biostatistics and Epidemiology, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Rui
authors.initials: R
authors.lastname: Xiao
authors.affiliation: Department of Nursing, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Heather
authors.initials: H
authors.lastname: Meldrum
authors.affiliation: Division of Neurology, Departments of Neurology and Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pa.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Abend
mesh_terms: D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006331:Heart Diseases / Q000151:congenital* / Q000601:surgery*; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D064926:Neurophysiological Monitoring; D011182:Postoperative Care; D012307:Risk Factors
keywords: EEG; Electroencephalography; cardiopulmonary bypass; congenital heart disease; neonatal seizures