Preterm infants are born with underdeveloped organs and immune systems, placing them at great risk for morbidity. They are more susceptible to inflammatory injury, particularly from conditions of prematurity mediated by inflammatory pathways such as bronchopulmonary dysplasia (BPD) and necrotizing enterocolitis (NEC).~L-CIT, an amino acid, is the first intermediate in the urea cycle as well as a precursor to arginine and nitric oxide (NO), which promotes blood flow. It is made in the intestine and has been shown to exert vasoprotective and anti-inflammatory effects. BPD-PH and NEC are two specific inflammatory diseases of prematurity involving CIT, arginine or NO deficiencies.~Evaluation of the safety and PK/PD of L-CIT supplementation for diseases involving CIT, arginine or NO deficiencies in preterm infants is important. Therefore, in this trial the investigator would like to evaluate the safety and pharmacokinetics/pharmacodynamics (PD) of L-CIT supplementation in preterm infants post surgical NEC and BPD-PH.
The purpose of this study is to evaluate the safety and explore the PK/PD of L-CIT supplementation in preterm infants to prevent the development of inflammatory pathways initiated by low levels of plasma CIT, specifically in preterm infants with post surgical NEC and BPD±PH.