Electroencephalographic seizures after neonatal cardiac surgery with high-flow cardiopulmonary bypass

Anesth Analg. 2010 Jun 1;110(6):1680-5. doi: 10.1213/ANE.0b013e3181dd5a58. Epub 2010 Apr 30.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthesia
  • Anesthetics / therapeutic use
  • Brain Chemistry / physiology
  • Cardiac Surgical Procedures / adverse effects*
  • Cardiopulmonary Bypass / adverse effects*
  • Cerebrovascular Circulation / physiology
  • Electroencephalography*
  • Female
  • Heart Defects, Congenital / surgery
  • Heart Ventricles / abnormalities
  • Humans
  • Hypnotics and Sedatives / therapeutic use
  • Infant, Newborn
  • Magnetic Resonance Imaging
  • Male
  • Oxygen / blood
  • Oxygen Consumption / physiology
  • Pain, Postoperative / drug therapy
  • Perfusion
  • Postoperative Care
  • Postoperative Complications / epidemiology*
  • Seizures / epidemiology*
  • Seizures / etiology*
  • Video Recording


  • Anesthetics
  • Hypnotics and Sedatives
  • Oxygen