The influence of thyroid substances on the absorption of pleural effusions.

Abstract

A good many patients suffering with pneumonia develop during the course of their disease pleural effusions. Some of these effusions are small and assume no clinical importance since they are usually absorbed at or soon after the crisis. Others are large and manifest themselves by physical and röntgenological signs. They last for a number of weeks, are accompanied by moderate fever prolonged convalescence and sometimes undergo purulent metamorphosis. The gross appearance of the fluid is usually straw-colored, of varying transparency and usually bacteria-free on culture.

The pathogenesis of these effusions is wholly unknown. It is possible that a certain type of pneumonia produces pleural exudation. This, if true, might explain the great frequency of this complication in the so-called influenza pneumonias. It can by no means, however, be said that the parapneumonic pleural effusions are confined to this type of pneumonia. It occurs frequently enough in conjunction with fibrinous lobar pneumonia.

Perhaps certain individuals particularly predisposed develop effusions in the pleural space in the course of their pneumonias. This idea seemed not unlikely in the light of Eppinger's work on edema.

Eppinger 1 found that certain cases of cardiac or kidney disease were frequently typified by an enormous generalized subcutaneous edema, that treatment of the heart by digitalis, restriction of the fluid intake, a salt-free diet or the administration of diuretics had no effect. In such cases the feeding of thyroid gland produced a marked diuresis, the disappearance of edema and distinct clinical improvement sometimes for an extended period.

He subjected these clinical observations to experimental investigation and found that there was a striking difference between the absorption of subcutaneous fluid from a normal and thyroidectonized animals. While normal animals absorbed considerable amounts of saline from the skin, thyroprivic animals could not absorb saline so injected.