A history of edema and its management

The obvious disfigurement caused by clinically evident edema has been a matter of medical concern for ages. Most of the early writings on the subject (Sumerian, Babylonian, Egyptian, Greek) center on dropsy, its causes and management. While reference to the heart is made in the ancient texts, much of the focus is on the abdominal (ascitic) accumulation of fluid. The role of the heart and "dropsy of the chest" began to be differentiated and attract attention sometime by the end of the seventeenth century, and were well appreciated by the eighteenth century. By the beginning of the nineteenth century the reports of John Blackall and Richard Bright provided new insight by differentiating dropsy into that of cardiac and renal origins. The role of salt, initially measured and thought in terms of its anion chloride, began to be appreciated by the middle to late nineteenth century. Its mobilization, however, remained problematic. The "cure de dechloruration", which gained fame by the end of the nineteenth century, was not always a successful undertaking. The treatment of dropsy, which centered on augmenting secretions (diaphoretics, purgatives) or mechanical removal of body fluids (bleeding, leeching, lancing), remained a frustrating and chancy undertaking for much of the time that medicine has had to deal with it. Although mercury had been advocated as a diuretic in the sixteenth century, even the organic mercurials that were introduced after World War II were limited in their effectiveness. The discovery of sulfanilamide-induced sodium bicarbonate diuresis in the late 1940s was to provide the first step in the new age of clinically effective diuretics, which began in the 1950s with the introduction of chlorothiazide, the first orally effective agent to mobilize sodium chloride. The subsequent introduction of more potent diuretics was made possible by concurrent advances in renal physiology and the understanding of the sodium handling by the kidney.