Biomarkers for Detection of Brain Ischemia

• Ten full-term neonates (> 36 week gestation), between 1-30 days of age, who present for arterial switch operation or Norwood operation will have 2 ml of blood drawn prior to cardiac surgery, 2 ml blood drawn each day after cardiac surgery as long as the patient remains in the intensive care unit with indwelling lines (maximum of 5 days) and 2 ml blood drawn on the day of the followup brain magnetic resonance imaging study (if not within the maximum of 5 days) to determine blood concentrations S100B and NSE.
• Brain magnetic resonance imaging (MRI) including T1, 2, DWI, spectroscopy, and magnetic resonance angiography, will be performed prior to cardiac surgery and following cardiac surgery in all study patients. Timing of the follow-up brain magnetic resonance imaging including T1, 2, DWI, spectroscopy, and magnetic resonance angiography, will be based on stability of the patient as assessed by the attending physician. Optimal timing for brain magnetic resonance imaging is 4 days postop.
• Maternal information including level of education, medications, and medical history will be obtained. Two mls of blood will also be obtained from the mother to determine maternal blood concentrations of S100B and NSE.
• Study patient clinical variables, including vital signs (heart rate, blood pressure, respiratory rate), systemic oxygen saturation by extremity pulse oximetry, near infrared spectroscopy (NIRS), routine laboratory values will be obtained at the time of each study blood sample.
• Operative variables including cardiopulmonary bypass time, aortic cross clamp time, circulatory arrest time, and hematocrit on bypass will be obtained. Transfusion quantity of packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate used in the operating room and in the cardiac intensive care unit will also be obtained
• Outcome variables including length of mechanical ventilation, hospital stay, and gross neurological abnormalities (clinical seizures) will be obtained.

Follow-up:

• All patients will have neurodevelopmental testing at 6 months after heart surgery.
• Another 2 mls of blood S100B and NSE will be obtained when the patient returns at 6 months for neurodevelopmental testing.

Inclusion criteria

• Ten consecutive full-term (>36 week gestation) neonates, one day to 30 days of age, presenting for cardiac surgery for arterial switch operation or Norwood operation will be eligible for the study.
• No patient will be excluded because of race or ethnicity.
• Parental or legal guardian consent will be obtained for all patients prior to enrollment.

Exclusion criteria

• Newborns with multiple organ abnormalities in addition to their heart defect such as diaphragmatic hernia, tracheo-esophageal fistula, and congenital syndromes involving multiple organs will be excluded from participation.
• Newborns with genetic syndromes associated with developmental delay will also be excluded.
• Newborns with birth asphyxia, 5 minute Apgar score < 5, will be excluded. Patients with multiple organ failure, syndromes, and birth asphyxia have other causes for neurodevelopmental abnormalities.
• Those patients unable to return for postop follow-up and neurodevelopmental testing will be excluded from participation.
• Those patients with parents/guardians who are unable to read or speak English will be excluded from participation.