354 



EDEMA 



excessive fluid escaping in these conditions carries with it no addi- 

 tional proteins, and to this extent transudates in statu nascendi are 

 protein-free. 



Transudates, even when produced by the same cause, vary in com- 

 position in different parts of the bodj', presumably because of varia- 

 tions in the permeability of the vessels in different vascular areas; just 

 as pleural, pericardial, peritoneal, and meningeal fluids normally 

 differ from one another. Thus C. S. Schmidt^" found the composition 

 of the transudates in different pares of the bodj^ of a patient who died 

 of nephritis to have the following composition: 



Table III 



Pleural 



Peritoneal Subarachnoid i Subcutaneous 



Water 



Solids. 



Organic matter. . 

 Inorganic matter 



963.95 



36.05 



28.50 



7.55 



978 . 91 

 21.09 

 11.32 



9.77 



988.70 



11.30 



3.60 



7.70 



As in this case, the general rule is that while che proportion of 

 salts remains nearly constant, the proportion of protein in edematous 

 fluids in different localities varies in decreasing order as follows: 

 (1) pleura; (2) peritoneum; (3) cerebrospinal; (4) subcutaneous.®^ 

 In the last-named location the specific gravity of edematous fluids 

 may be as low as 1.005, and the proteins even less than 0.1 per cent. 

 (Hoffmann"^). An increase in solids occurs after the eft'usion has 

 existed for some time, presumably because of absorption of water and 

 salts, leaving a slowly increasing proportion of proteins. Further- 

 more, the composition of the patient's blood has considerable influ- 

 ence on the composition of the effusion; this is particularly true 

 in the case of ascites from portal obstruction, the contents of the blood 

 coming from the intestine during digesoion modifying the composition 

 of the ascitic fluid, *^^ Thus Miiller,®* in a case of portal vein throm- 

 bosis, found in the ascitic fluid of a patient on an ordinary mixed 

 diet, 0.179 per cent, nitrogen; on a protein-rich diet, 0.2494 per cent. 

 N; on a protein-poor diet, 0.1764 per cent. N. In cachectic conditions 

 the proportion of proteins is less than in stronger individuals, and, 

 as in the blood plasma, the albumin decreases more rapidly than the 

 globuhn as the cachexia advances (Umber). *^^ 



Physical Chemistry of Edema Fluids. ^ — The differences be- 

 tween transudates and exudates depend almost solely on their protein 

 contents, for the non-protein elements are almost identical with 



*" Hoppe-Seyler's Physiol. Chemie. 



"1 Javal (Jour. phys. et path., 1911 (13), 50S) places the fluids in this order: 

 serum, peritoneal, pleural, sulK-utaiieous, cercl)rospinal. 

 «2 Deut. Arch. kliu. Med., 1S,S9 (44), 313. 

 «=• .See Deni.s and Miiiot, Arcli. Int. Med., 1C17 (20), 879. 

 «^ Deut. Arch. klin. Med., 1903 (76), 563. 

 «6 Zeit. klin. Med., 1903 (48), 364. 



