Lung strain and biological response in mechanically ventilated XXXX .

@entity1 @entity32 @entity650 @entity7 @entity26 @entity2843 @entity4155 @entity379 @entity687 @entity688 @entity647
PURPOSE: Lung tissue may exhibit a biochemical response to excessive deformation. Since strain has been proposed as a marker of such deformation, we studied the relationships between strain and matrix remodeling and @entity32 markers in mechanically ventilated @entity1 with and without @entity647 ( @entity647 ). METHODS: Twenty-two ventilated @entity1 were studied (16 with @entity647 , 6 controls). Clinical data, gas exchange and respiratory mechanics were recorded, and end-expiratory lung volume (EELV) was measured by @entity26 washin/washout. Extracellular matrix remodeling markers (procollagen, matrix metalloproteinases -2 and -9, @entity2843 ) and @entity32 markers ( @entity650 , @entity687 , @entity688 , @entity379 , @entity4155 , and @entity7 ) were measured in bronchoalveolar lavage fluid (BALF). Strain was computed as the ratio between tidal volume and EELV. @entity1 with @entity647 were divided into two subgroups according to the median strain value (0.27). RESULTS: @entity1 in the @entity647 group exhibited higher airway pressures, lower EELV and higher strain than the control group. There were no significant differences in gas exchange, respiratory mechanics, or the matrix remodeling markers between @entity647 @entity1 with normal and high strain. The subgroup of @entity1 with high strain showed a fourfold increase of @entity650 and @entity687 concentrations in BALF, compared with @entity1 with @entity647 and normal strain or @entity1 without @entity647 . In the whole sample, @entity650 and @entity687 concentrations in BALF were correlated with strain (Spearman's     =  0.67 and 0.77, respectively). CONCLUSIONS: Increased strain is associated with a proinflammatory lung response in @entity1 with @entity647 .
