The complications of acute pneumonia are pleurisy, empyema, pericarditis and endocarditis, while meningitis is responsible for a large percentage of the fatal cases. The pneumococcus has been found in the exudate in all these cases. Secondary pneumonias chiefly follow the specific fevers, as diphtheria, enteric fever, measles and influenza. Bacteriologically a number of different or ganisms have been found, together with the specific microbe of the primary disease ; the striking features of primary lobar pneu monia are often masked in these types.
This is partly general, partly by means of vac cines and serums. Many trials have been made with antipneumo coccic serum, but it has not been shown to have a very marked effect in cutting short the disease. The polyvalent serum of Romer has given the best results. Much more favourable results have been obtained from the use of a vaccine. The vaccine pro ducing the best results is autogenous, i.e., prepared from the pa tient's own strain of pneumococcus but in order to save time a "stock" mixture of known pneumococcus strains is employed, at least for a first injection. The value of vaccine treatment seems to depend upon recognition of the particular "type" of pneumo coccus causing the disease.
(Catarrhal or Lobular Pneumonia or Capillary Bronchitis). The term "broncho-pneumonia" is here used to denote a widespread catarrhal inflammation of the smaller bronchi which spreads in places to the alveoli and produces consolidation. All forms of bronchopneumonia depend on the invasion of the lung by micro-organisms. No one organism has however been constantly found which can be said to be specific, as in lobar pneumonia; the influenza bacillus, micrococcus catar rhalis, pneumococcus, Friedlander's bacillus and various staphyl ococci have been found and of ten the infection is mixed. Broncho pneumonia may occur as an acute primary affection in chil dren, but more usually is a secondary extension of the bronchitis found in infectious fevers, measles, diphtheria, whooping cough, scarlet fever and typhoid fever. In these it forms a frequent and often a fatal complication especially in early childhood. In adults it may follow influenza or complicate chronic Bright's disease or various other disorders. Bronchopneumonia also may follow
operations on the mouth or trachea, or the inhalation of foreign bodies into the trachea.
The lung shows numerous prominent dark red patches in con tact with depressed areas of collapsed and airless lung. Under the microscope the air vesicles and finer bronchi are blocked with epithelial cells and leucocytes, but there is no fibrinous exudation as in croupous pneumonia. In favourable cases resolution takes place by fatty degeneration, liquefaction, and absorption of the cells, but in weakly children the foci are liable to be infected by B. tuberculosis and the subsequent changes are those of tuber culosis. Broncho-pneumonia is a serious disease; the death-rate in children under five has been estimated at 3o to so%.
The treatment is mainly symptomatic. In children, should the secretion accumulate in the bronchial tubes an emetic is useful. Inhalations relieve the cough, and circulatory stimulants such as strychnine are valuable, together with belladonna and oxygen.
(Cirrhosis of the Lung) is a fibrosis chiefly around the walls of the bronchi and vessels, and in the intervesicular septa, which proceeds to such an extent as to invade and obliterate the air cells. The lung be comes shrunken, dense in texture and solid, any unaffected portions being emphysematous; the bronchi are dilated (see BRONCHIEC TASIS), the pleura thickened, and the lung substance often deeply pigmented, especially in miners, who are apt to suffer from this disease. This condition is present to some degree in almost all chronic diseases of the lungs and bronchi, but it is specially apt to arise in persons following dusty occupations such as those of colliers, flax-dressers, stonemasons, millers, etc., to which the term pneumonokoniosis is now applied (including anthracosis, siderosis, chalicosis and "grinder's rot"). (See MINERS' Plums's.) The malady is usually of long duration, many cases remaining for years in a stationary condition and even undergoing temporary improvement in mild weather, but the tendency is on the whole downward.