Pulmonary inflammatory cells in ventilated preterm infants: effect of surfactant treatment.

The aim of this study was to determine the effect of surfactant treatment on the number and distribution of inflammatory cells in bronchoalveolar lavage fluid (BALF) from mechanically ventilated preterm infants over the first week of life in relation to the subsequent development of chronic lung disease (CLD). The study included 25 babies who received surfactant on clinical grounds and 29 babies of similar severity who did not. BALF was collected on days 1, 3, 5, and 7 after birth. Cell counts were performed and differentials were calculated on 300 cells. CLD was equally common in both treatment groups. Of the 54 infants, 29 (53%) who developed CLD had a higher incidence of patent ductus arteriosus and air leak and needed a higher concentration of inspired oxygen on the fifth and seventh days of life. Babies who developed CLD had more polymorphonuclear leucocytes and fewer macrophages on days 5 and 7 than those who recovered. Surfactant treatment was associated with a higher total white cell count on day 3. Between days 3 and 7, macrophage numbers were higher in surfactant treated babies, whatever the pulmonary outcome. This data suggests that CLD was associated with persistence of high numbers of polymorphonuclear leucocytes in BALF at the end of the first week. Surfactant treatment caused a persistent increase in macrophage numbers. The association between persistent neutrophilia and CLD was unaffected by surfactant treatment.