Specificity of bronchoalveolar lavage for the diagnosis of fat embolism syndrome.

The diagnosis of fat embolism syndrome (FES) is relatively difficult because simple, quantitative criteria have been lacking. The results of a recent study, however, suggest that the diagnosis of FES can be made if more than 5 per cent of the cells in fluid obtained by bronchoalveolar lavage are lipid-laden. Our study was designed to assess the specificity of this lipid staining test of bronchoalveolar cells for diagnosing FES in a series of patients coming to the pulmonology clinic. Thirty-four consecutive patients with suspected pulmonary diseases, but not FES, underwent routine bronchoscopy. Bronchoalveolar fluid was applied to slides, fixed with formalin, and stained with oil red 0. Three hundred consecutive cells of each specimen were observed for red-staining droplets. More than 5 per cent of bronchoalveolar lavage cells stained for lipids in 25 of the 34 subjects. The calculated specificity, assuming a negative finding is defined as < or = 5 per cent lipid-laden cells in the sample, was 26.5 per cent. We conclude that staining of bronchoalveolar lavage cells for lipids is not a specific test for FES.