ROLE OF BRONCHOALVEOLAR LAVAGE IN THE DIAGNOSIS OF FAT-EMBOLISM SYNDROME

Fat embolism syndrome (FES) is a serious clinical disorder occurring i n trauma patients, The diagnosis of fat embolism syndrome may be diffi cult to establish clinically, We therefore wanted to investigate the u sefulness of bronchoalveolar lavage (BAL) in the diagnostic evaluation of fat embolism syndrome. We analysed the presence of fat droplets in BAL cells in 32 trauma patients (7 with full diagnostic criteria of f at embolism syndrome, 17 with incomplete diagnostic criteria, and 8 wi th no diagnostic criteria at the time of bronchoscopy), 9 nontrauma pa tients with acute respiratory failure and radiographic pulmonary infil trates, and a control group composed of 10 individuals. An increased p ercentage of oil red O positive alveolar macrophages (cut-off point >3 %) in BAL was found in 6 out of 7 patients with definite clinical crit eria of fat embolism syndrome, and in 6 out of 20 trauma patients with out the clinical diagnosis of fat embolism syndrome, In two patients w ith fat embolism syndrome, sequential BAL showed that the percentage o f positive macrophages decreased when the clinical manifestations disa ppeared, An increased number of BAL macrophages with fat droplets was also observed in two trauma patients without evidence of fat embolism syndrome after long-bone surgical intervention, By contrast, all nontr auma patients had a percentage of positive cells lower than 3%. Our fi ndings suggest that BAL oil red O positive macrophages are frequently observed in trauma patients irrespective of the presence of fat emboli sm syndrome, Conceivably, a high number of oil red O positive macropha ges could reflect clinically silent fat embolization.