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

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.

Ischemia/Reperfusion Injury After Neonatal Cardiac Surgery, Inflammatory Reaction After Neonatal Cardiac Surgery

delivering inhaled Nitric Oxide into the cardiopulmonary bypass circuit during neonatal cardiac surgery

inhaled Nitric Oxide not delivered to the cardiopulmonary bypass circuit during neonatal cardiac surgery

Change in Biochemical Markers of Ischemia/Reperfusion Injury and Oxidative Damage (Positive ~ Increase From Pre-op)

The primary study endpoints are to evaluate whether NO delivered through the neonatal cardiopulmonary bypass (CPB) circuit can decrease various biochemical markers of ischemia/reperfusion injury and oxidative damage. Markers to be analyzed will include cardiac troponin I, interleukins (IL), tumor necrosis factor, N-terminal prohormone for brain natriuretic peptide (NT-proBNP),lactate dehydrogenase (LDH), plasma anti-oxidant levels, plasma malondialdehyde (MDA) levels.

The secondary study endpoints are to evaluate whether NO delivered through the neonatal CPB circuit can decrease the clinical signs of ischemia/reperfusion injury and/or cardiac dysfunction. Clinical parameters (post surgery) include inotropic support, fluid balances, diuretic support, ventilator times, and length of ICU stay will be evaluated.

The Inotropic Score is an objective clinical tool used to quantify the need for cardiovascular support in children and adolescents after surgery and to predict prognosis of pediatric septic shock (higher score predicts higher risk or worse prognosis).The Inotropic Score is low if <= 20, intermediate if 21-30, and high if > 30. Formula used in the study: Daily inotropic score (mcg/kg/min) = Dopamine drip dose+ dobutamine drip dose+ (milrinone drip dose times 10) + (epinephrine drip dose times 100 )

Days to extubation and Pediatric Surgical Heart Unit (PSHU) length of stay (LOS) as measuring patient surgical outcomes.

include all complications that may happen after cardiac surgery for the whole period of hospital stay, that is expected to be around 1 month. This include renal failure, prolonged intubation and ventilatory support, infections..

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)