Broncho- Pneumonia from Inhalation. 297 



thetic, inhalation of food material into the lungs will occasionally 

 take place. If the operation is begun while the stomach is full, 

 digestion may be partially arrested and some gastric tympany in- 

 duced which tends to efface the folds of mucosa covering the 

 cardia. Under the struggles and compression of the abdomen 

 some of the contents of the stomach are forced into the oesophagus 

 and carried up to the pharynx, which being more or less unable 

 to perform its functions the food materials drop into the larynx 

 and are drawn down into the lungs. It may be added that dur- 

 ing a prolonged operation with the animal prostrate on its side, 

 there is liable to be hypostatic congestion of the lung which 

 lowers the resisting power, and causes it to readily succumb to 

 the irritation caused by the foreign bodies and the invasion of 

 the attendant microbes. Hence inhalation pneumonia after an 

 operation often assumes a dangerous development. Again in an 

 operation on nose or throat the blood r^ay pass into the lungs in 

 quantity. 



Lesions. Both lungs are usually affected, though as a rule, 

 neither is involved throughout. The centres of inflammation 

 are multiple, and the boundary of each diseased area usually 

 corresponds to the limits of a lobulette or group of lobulettes 

 clustered around the termination of the bronchium which was 

 blocked or primarily affected at that part. The individual lesion 

 represents a broncho-pneumonia in which the inflammation in 

 the lung tissue proper has been consecutive to the bronchitis. 

 On the surface of the lung when exposed these inflamed lobu- 

 lettes stand out above the level of the sound lung, red, firm, air- 

 less, noncrepitant and not collapsible. The inflamed areas are 

 most commonly in the anterior part of the lung near its lower 

 border, but may be at any point. They may show all the stages 

 of inflammation : the liquid infiltration, red, or dark red with re- 

 tained tenacity of the lung tissue and a free flow of lymph when 

 incised : the red hepatization with coagulation of the exudate, 

 firmness to touch, a dry, granular aspect of the cut surface, and 

 a marked friability under pressure ; in the centre of each af- 

 fected lobulette is seen the whitish engorged bronchiole with its 

 infiltrated peribronchial tissue, the contents being early liquid 

 and muco-purulent with excess of swollen granular epithelium ; 

 later it may be a firm coagulated mass, and later still a suppu- 



