PNEUMOTHORAX 365 



lower fat and greater lecithin content than typical chylous ascites. Gandin," 

 however, questions the possibility of always differentiating the three types of turbid 

 fluids as above indicated. Collecting all the recorded analyses in the literature 

 he finds wide discrepancies, as indicated in the following table: (The maximum and 

 minimum percentage figures are given for each component determined quantita- 

 tively, with the average in parentheses.) 



Adipose 

 Chylous (Chyliform) Pseudochylous 



Ether extract 0.065-9.2(1.65) 0.1-4.3(1.15) 0.007-1.86(0.25) 



Cholesterol + in 7, — in 2 + in 4 + in 3, — in 2 



Lecithin -j- in 4, — in 1 + in 3 + in 20, — in 2 



Sugar 4- in 46, — in 28 -f in 1, — in 4 + in 15, — in 14 



Dry residue 3.1-10.6(6.2) 1.6-11.7(5.1) 1.2-7.6(2.9) 



Protein 0.9-7.7(3.5) 0.6-6.8(3.0) 0.1-4.2(1.4)' 



"Pepton" + in 6, -in 4 + in 1, - in 2 + in 1, - in 5 



Ash 0.1-1.0 (0.59) 0.45-1.03 (0.65) 0.49-0.90 (0.73) 



It is quite evident that although the pseudochylous fluids usually contain little 

 fat, they often contain more than the minimal content found in the other forms. 

 Each type of fluid overlaps the others in one respect or another. Gandin states 

 that to produce a turbid fluid but 0.01-0.1 per cent, of finely emubionized fat 

 is necessary, and he believes that milky fluids always mean admixture of chyle, 

 rejecting the terms pseudochylous and chyliform as unwarranted. He admits 

 that fluids may contain droplets of fats not emulsionized, and hence not milky, 

 which may be properly called adipose fluids. There are no characteristic chemical 

 differences in the fats extracted from the different types of fluids. 



Chemistry of Pneumothorax 



In connection with the subject of exudates the above topic may appropriately 

 be considered. The composition of the gases found in the pleural cavity in pneu- 

 mothorax will necessarily vary greatly according to the cause. If the pleural 

 cavity is in free communication with the exterior, the gas will be simply slightly 

 modified air; for example, Ewald^^ found the following proportions in the gases in 

 such a pneumothorax: CO2, 1.76 per cent.; O, 18.93 per cent.; and 79.31 per cent. 

 N. Here the proportion of CO2 is even a little less than in ordinary expired air, 

 which contains 3.3-3.5 per cent. When air .enters a closed pleural cavity and no 

 effusion follows, it is slowly absorbed until a mixture of about 90 per cent. N, 4 per 

 cent. O and 6 per cent. CO2 results; but if there is a serous effusion the oxygen 

 disappears nearly or quite completely (Tobiesen).*^ In a seropneumothorax 

 Ewald found 8.13 per cent, of CO2, 1.26 per cent, of O, and 90.61 per cent, of N, 

 which is quite similar to the proportions of the gases in dry pneumothorax. Puru- 

 lent pneumothorax generally shows more CO2 than the serous form, the average in 

 the former being 15-20 per cent., in the latter 7.5-11.5 per cent. The average of 

 the analyses in six cases of pyopneumothorax is given by Ewald as 18.13 per cent. 

 CO2, 2.6 per cent. O, and 79.81 per cent. N. In open pyopneumothorax the gas 

 approaches more closely the composition of air, but usually shows a slight excess of 

 C()2; it is thus possible by a determination of the carbon dio.xide to determine 

 quite accurately whether a given pneumothorax is in communication with the 

 outside air. The transformation of a purulent into a putrid pneumothorax is 

 accompanied by an increase of CO3, even as high as 40 per cent, having been found. 

 The products of decomposition by the putrefactive saprophj'tes also are present, 

 one analysis having shown 4.3 per cent, of hydrogen, 6.25 per cent, of methane, and 

 traces of hydrogen sulphide. 



Infection of a pleural effusion by gas-producing organisms may also convert it 

 into a pneumothorax, although this is not a common occurrence. The gases then 



82 Complete literature and resume given by Clemens, in Ott's "Chem. Path 

 der Tuberculose," Berlin, 1903, p. 406. 



" Beitr., z. lOin. d. Tuberk., 1911 (19), 451; 1911 (21), 109; Deut. Arch. klin. 

 Med., 1914 (115), 399. 



