Small intestinal hypoxic injury and use of arginyl-glutamine dipeptide: Applications to pediatrics

Abstract

Premature infants are exposed to various perinatal stresses, including hypotension, hypoxia, hyperoxia, hypothermia, feeding, anemia, and umbilical vessel catheterization. Hypoxia-associated small intestinal injury may occur in a variety of severe pathophysiologic conditions in pediatric patients such as perinatal asphyxia, shock, or other hypoxic-ischemic states. It has been speculated that when such events occur, intestinal blood flow will diminish [1] via the diving seal reflex (reflex with circulatory shunting to selectively perfuse the brain, heart, and kidneys at the expense of other "nonvital" organs such as intestine and extremities), which can result in intestinal injury, systemic inflammatory response syndrome (SIRS), bacterial translocation, distal organ injury, and even multiple organ failure. Hypoxic intestinal injury-related diseases can have a profound impact on children’s health. For example, necrotizing enterocolitis (NEC) is one of the most common and devastating diseases found in premature infants in neonatal intensive care units (NICU) with high mortality, long hospitalization, and high financial cost [2]. It can also affect distant organs such as the brain and place affected infants at substantially increased risk for neurodevelopmental delays. Although evidence shows that the most common form of NEC seen in preterm infants is not triggered by a primary hypoxic-ischemic event [3], hypoxic/ischemic injury of the bowel has been thought to be one of the main risk factors in term infants, especially those with congenital heart disease who have low blood flows to the gastrointestinal tract.