Lipids in the pulmonary circulation after fatal trauma. A postmortem study

Lipids in the pulmonary circulation were determined biochemically and histologically in seven patients (group A) who died following multiple blunt trauma and in five patients (group B) who died of some other traumatic or nontraumatic cause. Autopsy was performed on average 4.5 hours after death. Blood samples were collected from the right ventricle (RV) and the left atrium (LA). The vasculature of the left lung was perfused in a retrograde direction. The inferior lobe of the right non-perfused lung was examined histologically. Intravascular pulmonary fat was observed in 4/6 cases in group A and in 1/5 cases in group B. No intravascular fat was observed in the tissue samples of brain, liver or kidney. The concentration of free fatty acids (FFA) in blood from RV was higher than in blood from LA both in group A (P is less than 0.01) and in group B (P is less than 0.05). The considerable difference in concentrations of FFA between RV and LA and the low concentration of FFA in the lung perfusate may be due to some kind of "fixation" of FFA in the lung tissue, possibly connected with the aetiological factors of the fat embolism syndrome (FES).