CHARACTERIZATION OF TRACHEAL ASPIRATES (TA) FROM NEWBORNS WITH SEVERE RESPIRATORY FAILURE 1577

Introduction: In order to characterize differences in the pathophysiology of RDS in preterm infants compared with ARDS-like disease in newborns, we prospectively obtained TA (tracheal aspirates) from newborns requiring mechanical ventilation. Subjects and methods: TA were obtained within 48 h of intubation in 17 infants < 32 weeks of gestation(group 1; mean GA 29 ± 2.5 (SD) wks) and 14 newborns (group 2; mean GA 38 ± 3.2 (SD) wks). TA were cytocentrifuged and the cells were differentiated morphologically and immunocytologically (CD62L and CD11b). Total protein (TP), α₂ -macroglobulin (α₂-MG) and elastase-al-proteinase inhibitor complex (E-α₁-PI) were analyzed and compared with controls requiring mechanical ventilation without underlying pulmonary diseases. Results: In both groups neutrophils and macrophages were found in TA, polymorphonuclear cells were positive for CD 62L and CD 11b. The table summarizes the results of the biochemical variables (mean ± SD): Conclusions: We demonstrated evidence for significant leukocyte endothelium-interactions as a consequence of granulocyte activation in the early course of both RDS and ARDS-like disease. Furthermore, significantly increased E-α₁-PI concentrations in newborns ≥ 32 weeks suggest inflammatory mechanisms in ARDS-like disease. We conclude TA analyses might be helpful differentiating between both types of neonatal respiratory failure.

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