CONTRIBUTION OF BRONCHOALVEOLAR LAVAGE TO THE DIAGNOSIS OF POSTTRAUMATIC PULMONARY FAT-EMBOLISM

Objective: To verify whether the determination of the percentage of ce lls recovered by bronchoalveolar lavage and containing fat inclusions is a useful diagnostic tool of posttraumatic pulmonary fat embolism. D esign: Prospective study. Setting: Surgical Intensive Care Units in tw o university hospitals. Patients: 56 successive trauma patients needin g prolonged postinjury mechanical ventilation, including 4 with clinic al definite fat embolism syndrome, 5 in whom the diagnosis had been cl inically suspected but was impossible to confirm or exclude before bro nchoscopy, and 47 with no clinical evidence of the syndrome. Control g roups included 8 patients without previous trauma who developed ARDS a nd 6 healthy surgical patients. Methods: Bronchoalveolar lavage was pe rformed within the first posttraumatic 3 days in trauma patients, at t he beguining of the pulmonary disease in non trauma ARDS patients and just after anesthesic induction in healthy ortopedic patients. The mag nitude of lipid content in alveolar cells was compared with the clinic al pattern of the pulmonary fat embolism syndrome retrospectively eval uated at the seventh day postinjury in trauma patients. Results: All t he patients with definite fat embolism syndrome had more than 70% of l avage cells containing fat droplets. The group of patients in whom the diagnosis of the fat embolism syndrome was suspected had percentages of fat cells above 30% in 4 out of 5 patients. A percentage of fat cel ls above 30% was only observed in 7 out of the 47 patients without cli nical evidence of the syndrome. The percentage varied between 0% to 35 % in the group of non trauma ARDS patients and between 0 to 5% in heal thy surgical patients. Conclusion: Lipid inclusions in alveolar cells are common during traumatic and non-traumatic respiratory failure. Det ermination of the percentage of cells recovered by bronchoalveolar lav age and containing fat droplets may contribute to the diagnosis of the fat embolism syndrome in mechanically-ventilated trauma patients with respiratory failure provided that the significant threshold would be 30%.