ABSTRACT
Studies of the mechanisms of disease pathogenesis and progression in human infants are hampered by the lack of availability of pulmonary tissue for study. Obtaining bronchoalveolar lavage (BAL) fluid to reach pulmonary cells and epithelial lining fluid has been used to overcome this shortcoming. Problems that complicate the use of these materials include (1) the use of suboptimal and nonstandardized techniques for obtaining fluids, (2) lack of adequate reference indices, (3) lack of normal control data from healthy premature infants, and (4) safety issues. Because of these concerns, each study involving use of BAL must be examined critically, and results should be considered to be only semiquantitative. Despite these difficulties, useful concepts concerning bronchopulmonary dysplasia (BPD) pathogenesis have been suggested and supported through human clinical studies that have depended on BAL fluids. Through use of lavage or pulmonary effluent fluids, considerable information has been reported on tracheobronchial-alveolar cellularity, inflammatory cytokines, and other mediators, proteases and antiproteases, and surfactant components, during the progression of BPD. Less information has been presented about oxidants and antioxidants and about infectious agents obtained from BAL. In this chapter we discuss various
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aspects of the airway lavage procedure as it is used in infants, and we describe a few specific examples in which BAL materials have helped provide insight into the pathogenesis of BPD.
