Efficacy of Nitric Oxide Administration in Attenuating Ischemia/Reperfusion Injury During Neonatal Cardiopulmonary Bypass

Efficacy of Nitric Oxide Administration in Attenuating Ischemia/Reperfusion Injury During Neonatal Cardiopulmonary Bypass.

Around 7500 neonates born yearly in the United States have complex congenital heart disease that require surgical repair in the first few days of life. The complexity of the surgical repair requires long periods of cardiopulmonary bypass (CPB) and the use of intermittent periods of low flow or complete circulatory arrest. The immature neonatal vital organs are more prone to the complications of the cardiopulmonary bypass circulation, namely ischemia/reperfusion (I/R) injury and systemic inflammatory response. Inhaled nitric oxide (NO) is used frequently in neonates for the treatment of pulmonary hypertension, Additionally, many studies have shown that NO has an anti-inflammatory effect by reducing I/R injury and endothelial dysfunction.

The purpose of this pilot study is to assess the efficacy of NO administration via the CPB circuit in attenuating the CPB induced I/R injury and systemic inflammatory reaction in neonates undergoing repair of complex congenital heart defects. Specific goals will be to demonstrate that NO use via CPB will:

• Decrease markers of I/R injury and systemic inflammatory response.
• Decrease platelet activation leading to reduced postoperative bleeding and transfusion requirements.
• Decrease postoperative organ dysfunction, and hence decrease operative mortality and postoperative morbidity.

Twelve neonates undergoing repair of complex congenital heart defects will receive NO via the CPB circuit, for the duration of surgery. They will be compared to a control group of 12 similar patients. Serum levels of different ischemic reperfusion injury and inflammatory markers will be measured at different time points after surgery and will be correlated with different end organ function tests and clinical course in the postoperative period. The results will be compared between the two groups to try to determine the clinical benefit of NO administration through CPB circuit.

Inclusion Criteria:

• Neonates, age 0-30 days
• Full term, > 37 weeks gestation
• Birth weight ≥ 2.6 kg

Exclusion Criteria:

• Preoperative sepsis
• Preoperative renal dysfunction
• Preoperative intracranial hemorrhage
• Chromosomal abnormalities and/or genetic syndromes
• Prior intervention (catheter based or surgical)