[Post-traumatic systemic fat embolism syndrome. Retrospective autopsy study].
INTRODUCTION: The obstruction of blood vessels or heart chambers with fat globules, reached by circulation, is fat embolism [1, 2]. Clinical manifestation of the presence of fat emboli in vital organs is Fat Embolism Syndrome (FES). This syndrome is characterized by neurologic, respiratory and cutaneous signs and different symptoms [5-8], grouped in major and minor signs by Gurd and Wilson. PURPOSE: The purpose of this paper is to analyze and compare the autopsy findings and clinical data in cases where FES is emphasized as the single or concurrent cause of death after performed autopsy. MATERIAL AND METHOD: This retrospective study includes the autopsy material of the Institute of Forensic Medicine in Belgrade, over the period 1985-1998 when FES is pointed out as a cause of death. The severity of trauma for each case was determinated by Injury Severity Score (ISS). The microscopical findings, which are incorporated in autopsy reports, were separately analyzed. The sample was statistically prepared (chi 2 test, ANOVA). RESULTS: The sample included 56 patients: 43 males (average age 51.65 years) and 13 females (average age 65.07 years). The proportion of men was more significant (chi 2 test = 8.98; p < 0.01) as well as the persons aged 60-80 years (ANOVA, p = 0.0017). In our sample there were more pedestrians (32 patients) (Anova, p-->0) than other injured persons. Fractures of the femur, tibia and/or pelvic bones were typical injuries in each examined patient. The authors combined the clinical and autopsy data in order to get the ISS value. The mean ISS value was 20.65 (SD = 7.47). The mean value of the surviving period was 5.8 days (SD = 3.6). The sample distribution of surviving period was normal (Gauss distribution). The latent period from injury to the onset of the first major FES signs was about 24 hours (32 patients had one of the major FES signs during the first 24 hours after admission; 8 patients after 24-48 hours and 10 after 48 hours after admission). Six patients who were admitted in deep coma were not analyzed. DISCUSSION: The most common first major FES sign refers to the sudden onset and rapid progressive qualitative or/and quantitative disturbance of conciousness (deep coma developed after a short period, without obvious causes) in 40 cases. In six patients ophthalmological characteristic retinal blood vessels changes were found: they pointed to FES. The second major FES sign was respiratory disturbance alone (manifested at first as chest pain and spitting of blood, and later as disturbances in artery blood gas analysis), or in combination with disturbed conciousness--in 15 cases The characteristic later developed cutaneous chest and axillary rush as the only specific FES sign was established in 11 cases (surviving period was from 5 to 12 days), but clinically only in one case. In addition to objective difficulties, in most cases, one of the minor FES signs was established: in 22 cases haematological disturbances (i. g. low value of haematocrit, haemoglobin, number of platelets or/and coagulation factors); in 13 cases hyperpirexia, and other minor FES signs only occasionally. The postmortem diagnosis of FES could be established only microscopically (Sudan III staining). Bronchopneumonia (24 cases), hyaline membranes (7 cases), as well as lung oedema and alveolar haemorrhages (in almost two thirds of the sample) were the most common microscopical findings in the lung as complications of FES. The most characteristic postmortem brain findings in FES are dotted perivascular haemorrhages, mostly in the white matter. These changes were not established in 7 cases (surviving period was 1 to 2 days), but the especially stained sections pointed to FES as the cause of death. In addition to various chronic pathological changes, only intestinal haemorrhages and/or oedema of solid organs could be established microscopically. CONCLUSION: In the analyzed sample of 56 patients who died of FES, FES was clinically established onl