Fat conglomerations have been observed in the pulmonary capillaries in various disease states l 11, 30, 53, 56, 59 l These states need not have much else in common other than the obviously ubiquitous presence of unstabilized, embolized, or deposited fat; nor need the source of origin of the fat be the same.
Fat globuli or emboli have been induced experimentally either by mimicking clinical trauma l 7, 30, 37, 55 l or by injecting fats intravenously with the inevitable result of fat globuli harbouring in the lung capillaries l 36 l In the latter case especially, the only factor in common with any clinical state may be the blocking of lung circulation and the consequences of the toxicity of the injected material.
In necropsy studies, fat emboli (FE)' have been discovered in the lung capillaries, especially after mechanical trauma l 61 l. Soon after the first morphological findings, the clinical fat embolism syndrome (FES) was described by von Bergmann l 8 l. As early as in 1898, Carrara l 11 l described the following, still pertinent symptoms: dyspnoea, lung oedema, mental disturbances, fever, and fat in urine.
Since the development of the concept of post-traumatic pulmonary insufficiency l 41 l, various aetiological factors have been found to result in similar lung changes and hypoxaemia in surgical patients On the other hand, this generalized concept has led to the obscuring of the concept of FES, which, for clinicians working with skeletal trauma, is still a well definable entity l 45, 53, 56 l The acceptance of FES as an entity in connection with musculoskeletal trauma does not exclude the possibility of other types of respiratory distress in these patients l 19 l.
This article is an effort to review briefly some of the vast literature concerning FE and FES after musculoskeletal trauma, to give an account of our own investigations concerning the diagnosis, to evaluate the possibilities of experimental research in clarifying the clinical syndrome, and to survey the therapeutic alternatives In the scope of this article, it is impossible to cover all the investigations which have increased our knowledge of this syndrome The references may be considered as examples of the research work which has been done to elucidate the various aspects of the problem.