Experimental study of early diagnosis and treatment of fat embolism syndrome

An experimental animal model has been established using i.v. fat injection to mimic fat embolism syndrome (FES). Fourteen healthy mongrel dogs who were administered 0.7 ml/kg of fluid marrow fat obtained from the long bone marrow cavity of mongrel dogs were divided into control and therapeutic groups. The therapeutic group (n = 7) was given dexamethasone (1.0 mg/kg) and repeated every 6 h i.v. During 48 h of observation, blood gas analysis and frozen sections were performed on blood samples collected from the pulmonary vessels by a floating catheter and from a peripheral vein at different time intervals. The frozen sections were stained with Oil Red O. Positive results were seen 2 h after fat injection in both pulmonary and peripheral blood samples of both control and therapeutic groups. By computer image analysis, the average median number of fat droplets per section and the average median diameter of fat droplets in pulmonary blood of the control group were found to be significantly higher and larger than were those of the therapeutic group. The average median number and diameter of fat droplets in pulmonary blood were significantly higher and larger than were those of peripheral blood in both control and therapeutic groups. These findings correlated well with blood gas changes and the clinical appearance of the experimental animals. The fat droplets from pulmonary or peripheral blood as demonstrated by Oil Red O staining in combination with blood gases changes [PaO2 < 7.99 KPa, difference between the alveolar and arterial oxygen tension (P(A - a)O2) > 6.09 KPa] may be a rapid method for screening of an earlier diagnosis of FES.(ABSTRACT TRUNCATED AT 250 WORDS)