title: Electroencephalographic seizures after neonatal cardiac surgery with high-flow cardiopulmonary bypass.
abstract: BACKGROUND
  Postoperative electroencephalographic (EEG) seizures are reported to occur in 14% to 20% of neonates after cardiac surgery with cardiopulmonary bypass (CPB). EEG seizures are associated with prolonged deep hypothermic circulatory arrest and with adverse long-term neurodevelopmental outcomes. We performed video/EEG monitoring before and for 72 hours after neonatal cardiac surgery, using a high-flow CPB protocol and cerebral oxygenation monitoring, to ascertain incidence, severity, and factors associated with EEG seizures.
  
  
  METHODS
  The CPB protocol included 150 mL/kg/min flows, pH stat management, hematocrit >30%, and high-flow antegrade cerebral perfusion. Regional cerebral oxygen saturation (rSo(2)) was monitored, with a treatment protocol for rSo(2) <50%. EEG was assessed for seizures.
  
  
  RESULTS
  Sixty-eight patients (36 single ventricle [SV] and 32 2-ventricle [2V]) were monitored for a total of 4824 hours. The total midazolam dose was 2.4 mg/kg (1.5-7.3 mg/kg) (median, 25th-75th percentile) for the SV group and 1.3 mg/kg (1.0-2.7 mg/kg) for the 2V group (P = 0.009). One SV patient experienced 2 brief EEG seizures postoperatively (1.5% incidence; 95% confidence interval: 0.3%-7.9%). The SV patients experienced a significant incidence of cerebral desaturation (rSo(2) <45% for >240 minutes total) perioperatively (18 of 36 SV vs 0 of 32 2V patients, P < 0.001). This difference did not affect electrographic seizure occurrence or other EEG characteristics.
  
  
  CONCLUSIONS
  EEG seizures are infrequent in neonates undergoing surgery with high-flow CPB. Cerebral desaturation did not affect EEG seizure occurrence; however, benzodiazepines may play a role in suppressing postoperative seizures caused by cerebral hypoxemia in this patient population. Using this anesthetic and surgical protocol, EEG seizures are a poor surrogate marker for acute neurological injury in this population.
authors.affiliation: MHCM, Texas Children's Hospital and Baylor College of Medicine, 6621 Fannin, WT 17417B, Houston, TX 77030, USA. dra@bcm.tmc.ed
authors.forename: Dean B
authors.initials: DB
authors.lastname: Andropoulos
authors.forename: Eli M
authors.initials: EM
authors.lastname: Mizrahi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Hrachovy
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Stayer
authors.forename: Ann R
authors.initials: AR
authors.lastname: Stark
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Heinle
authors.forename: Emmitt D
authors.initials: ED
authors.lastname: McKenzie
authors.forename: Heather A
authors.initials: HA
authors.lastname: Dickerson
authors.forename: Marcie R
authors.initials: MR
authors.lastname: Meador
authors.forename: Charles D
authors.initials: CD
authors.lastname: Fraser
mesh_terms: D000758:Anesthesia; D000777:Anesthetics / Q000627:therapeutic use; D001923:Brain Chemistry / Q000502:physiology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002560:Cerebrovascular Circulation / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006352:Heart Ventricles / Q000002:abnormalities; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010149:Postoperative Pain / Q000188:drug therapy; D010477:Perfusion; D011182:Postoperative Care; D011183:Postoperative Complications / Q000453:epidemiology*; D012640:Seizures / Q000453:epidemiology* / Q000209:etiology*; D014741:Video Recording
chemical_list: D000777:Anesthetics; D006993:Hypnotics and Sedatives; D010100:Oxygen