1 054 Ptieuuiuperii-ardiuni. 



through which gases may pass from the reticulum into the 

 pericardial cavity (see p.* 1042) ; the same occurs in ichorous 

 pericarditis in which putrefactive gases are formed. Atmos- 

 pheric air enters the pericardium only in very exceptional 

 cases, for instance after penetrating wounds of the pericardium 

 by external agencies, by fractured ribs, by breaking down of 

 a lung cavity which had been adherent to the pericardium. 



Symptoms. An intense tympanitic percussion sound is 

 noticeable in the region of the heart, over an area which is 

 sharply limited at the periphery and corresponds to the cardiac 

 area; this sound is sometimes metallic in character. In pure 

 pneumopericardium the heart sounds are high and metallic, 

 owing to the resonance of the pericardium. In most cases, 

 however, the pericardium contains fluid exudate as well as gases, 

 and this gives rise to loud splashing, clacking noises which 

 are sometimes audible from a distance of several steps, and 

 which are often compared with the noise made by a millwheel 

 (bruit de moulin). 



The clinical picture is supplemented by the more or less 

 marked symptoms of jDericarditis (p. 1043) which is usually 

 present, or the signs of gas accumulation appear only in a 

 certain stage, for instance, at the beginning or toward the 

 end of pericarditis. In making a diagnosis it should be re- 

 membered that a tympanitic sound in the region of the heart 

 may also be produced by infiltration of the lung portions in 

 the vicinity of the heart or by diaphraginatic hernia (portions 

 of intestine in the pericardium [Pettit]). 



Prognosis. Pneumocardium is always of very unfavorable 

 significance and a chance for recovery exists only in those 

 rare cases of injury to the pericardium in which infection 

 failed to occur. 



Treatment. The same treatment is here indicated as in 

 acute pericarditis, but the necessity for operation is greater. 



Literature. Petit, Kec, 1902. 679 (see also Lit. on pericarditis). 



