Electroencephalographic Seizures After Neonatal Cardiac Surgery with High-Flow Cardiopulmonary Bypass

• Published in: Anesthesia and analgesia Vol. 110; no. 6; pp. 1680 - 1685
• Main Authors: Andropoulos, Dean B., Mizrahi, Eli M., Hrachovy, Richard A., Stayer, Stephen A., Stark, Ann R., Heinle, Jeffrey S., McKenzie, Emmitt D., Dickerson, Heather A., Meador, Marcie R., Fraser, Charles D.
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD International Anesthesia Research Society 01.06.2010; Lippincott Williams & Wilkins
• Subjects: Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics - therapeutic use; Biological and medical sciences; 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; Medical sciences; Oxygen - blood; Oxygen Consumption - physiology; Pain, Postoperative - drug therapy; Perfusion; Postoperative Care; Postoperative Complications - epidemiology; Seizures - epidemiology; Seizures - etiology; Human; Cardiopulmonary bypass; Nervous system diseases; Newborn; Convulsion; Surgery; Epilepsy; Central nervous system disease; Anesthesia; Neurological disorder; Cerebral disorder
• DOI: 10.1213/ANE.0b013e3181dd5a58
• ISSN: 0003-2999

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. 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. 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. 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.