Description |
Necrotizing Enterocolitis, or NEC, is a common intestinal disease of preterm neonates. It is believed that bacterial colonization increases the risk of NEC. This study examines whether the type of ventilation of the neonate, either mechanical ventilation (MV) or non-invasive support (NIS), and the length of the ventilatory period, increases the bacterial colonization and thus, indirectly, the risk of NEC. Seven groups of preterm lambs were studied, four experimental groups and three age-matched control groups. The experimental groups were ventilated in different ways for different lengths of time. The control groups were not ventilated at all. A cross-section of the distal ileum of each lamb was placed on a slide, and the ratio of CD3-postive lymphocytes to tissue points was calculated. The principal result of this study is that the number of CD3-positive T-lymphocytes was significantly greater in both groups of preterm lambs after 21 days of respiratory support compared to the term, unventilated, gestationa l age-matched reference group. These results suggest that being preterm and supported for 21 days leads to the accumulation of CD3 -positive T-lymphocytes, and thus a higher risk of developing necrotizing enterocolitis. Method of respiratory support did not make a difference in the accumulation. |