Transpyloric feeding and microaspiration-induced lung injury in preterm infants

About 1.45% of all infants (2 million/year, worldwide) are born extremely premature (birth weight < 1500 grams). A majority of them require respiratory support due to respiratory distress syndrome. Twenty to thirty percent of extreme premature infants develop a chronic lung disease called bronchopulmonary dysplasia (BPD). BPD causes significant mortality and long-term morbidities including abnormal pulmonary function, impaired growth, and neurodevelopmental delay. Microaspiration from gastroesophageal reflux (GER) may have a potential role in the pathogeneses of BPD. Aspiration causes mechanical obstruction and chemical injury to the airways, initiating an inflammatory response in the lungs. Preterm ventilated infants are more likely to develop pulmonary aspiration due to prone positioning, the presence of nasogastric tubes, and the use of un-cuffed endotracheal tubes. We have demonstrated that the level of tracheal aspirate (TA) pepsin, a reliable marker of gastric aspiration, is higher in preterm infants who developed BPD. Currently, there is no effective therapy for preventing aspiration in premature ventilated infants. Transpyloric (TP) feeding could potentially decrease GER and microaspiration but there is no supporting data. Therefore, we hypothesize that TP feeding will reduce microaspiration and lung inflammation and improve respiratory outcomes in ventilated premature infants. Our approach is to a) assess microaspiration by measuring pepsin A and lung inflammation by quantifying inflammatory mediators in TA samples and b) evaluate respiratory outcomes in ventilated preterm infants with and without TP feeding. We expect that the TP feeding will decrease microaspiration and lung inflammation, and reduce respiratory support. This study will generate data that can be used for formal hypothesis testing and writing future grants to study the effects of microaspiration on lung inflammation. A large clinical trial with extramural funding can be planned based on data from this study on the role of TP feeding for prevention of BPD or reducing severity of BPD.