The objective of this autopsy-based study was to investigate the pathology of human blast
lung injury using histology,
Fat Red 7B staining, immunohistochemistry, and scanning electron microscopy on lung specimens from eight medicolegal autopsy cases of fatal close-range detonations of chemical
explosives. The micromorphologic equivalents of human blast
lung injury can be summarized as follows: diffuse alveolar overdistension, circumscribed interstitial
hemorrhages showing a cufflike pattern around pulmonary vessels, venous
air embolism, bone marrow
embolism, and pulmonary
fat embolism.
Hemorrhages within the lung parenchyma that were present in this study in blast victims without coexisting blunt or penetrating chest
trauma must be regarded as potentially life-threatening intrapulmonary
bleeding sites in survivors. In addition, the potential clinical importance of the presence of massive pulmonary
fat embolism, which has, to the best of our knowledge, not been described previously in human blast
lung injury, must be emphasized because pulmonary
fat embolism may be a leading cause of the rapid respiratory deterioration with progressive
hypoxia and development of
acute respiratory distress syndrome in blast victims who survive. Furthermore, this study provides evidence that
air embolism presenting in blast victims is not a mere ventilation-induced artifact.