Early diagnosis of fat embolism syndrome by automated image analysis of alveolar macrophages

Abstract

To evaluate the value of automated semiquantitative analysis of fat within alveolar macrophages as an early diag-nostic tool for fat embolism syndrome (FES), we investigated 3 patients with respiratory failure following long-bone frac-tures. The mean area of fat droplets per alveolar macrophage was determined in pixels and, additionally, the percentage of the evaluated areas was calculated. In 2 patients, the diagnosis of FES could be established as early as 24 hr after trauma. Both patients showed an increase in the area of fat per alveolar macrophage (pixels: 851, 1069) as well as in the percentage of fat area per alveolar macrophage area (40.04%, 52.73%), whereas the analysis of the bronchoalveolar lavage (BAL) specimens of a third patient, who later recovered without ap-pearance of clinical signs of FES, revealed only minimal fat content (pixels: 82; 3.82%). Automated semiquantitative anal-ysis of fat within alveolar macrophages may be helpful in the early diagnosis of FES.