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.