BRONCHOALVEOLAR LAVAGE USING DIFFERENT VOLUMES OF SALINE

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bronchoalveolar lavage (BAL) is a procedure commonly used for sampling of both cellular and noncellular components from the epithelial surface of the lower respiratory tract. Sampling the contents of the lower respiratory tract has led to a better understanding of components of the alveolar epithelial lining fluid in normal persons and in individuals with a variety of lung diseases. This procedure is not standardized and can vary in terms of the volume of saline lavage used. Usually the total volume used per site is between 100 cc and 150 cc with the total maximum volume being no greater than 300 cc. The volume of individual aliquots used by clinicians and researchers ranges from 20 cc to 100 cc. Radiographic changes have been demonstrated following lavage which are not clearly due to retained fluid, but may be secondary to loss of surfactant leading to localized areas of atelectasis. Though BAL itself does not typically lead to global alterations in lung function, it may lead to localized alterations in lung mechanics. An understanding of these local changes in patients with normal lung function following lavage may provide further insight into lung function in health and disease. For this pilot study, these investigators will study six subjects who will undergo bronchoscopy with BAL, with CT scanning prior to the procedure, and at various time points following the procedure. They will lavage a segment in each lung using two different volumes of saline. They will use 5 x 20 cc aliquots and 4 x 50 cc aliquots, both of which have been used safely in large numbers of patients. They will examine the cell count, differential and surfactant levels in each aliquot of fluid. Comparison of successive aliquots from the same lung as well as the cumulative lavage between lungs within each subject will be done. CT scanning will be used to validate the location of the lavage and to characterize the local changes within the lung following the lavage. It will further assist in characterizing the resolution of those changes following lavage. They hypothesize that bronchoalveolar lavage leads to transient areas of atelectasis which alter the local mechanical properties of the lung. This can be demonstrated by CT and these abnormalities are positively correlated with the volume of lavage used, and the amount of surfactant recovered. They further hypothesize that over distension of the alveoli, using the larger volumes of saline, with loss of surfactant causes mild, local injury associated with increased levels of neutrophils and red blood cells.