PNEUMONIA, n11-mn'n'fn Neo-La t., from Gk. rvevnovia, disease of the lungs, from pneilmon, lung, from ryas, pectin, to breathe). An inflammation of the substance of the lung. There are three well-defined forms: Acute lobar pneumonia, broncho-pneumonia, and chronic in terstitial pneumonia.
Acute pneumonia is called lobar because it in volves usually an entire lobe or successive lobes of the Imig; croupous from the character of the exudation into the air cells or alveoli. 'l'c dis ease is due to a specific germ, the. Pneuniocomas or Diplocoecus pneumonia', although streptocoeei and staphylococci are always found with it. It is infections and in a measure ouitagious, and sometimes occurs epidemically in institutions and houses. it is apt to attack persons in a de pressed physical or mental condition; it is more in the spring and autumn than at other times, and is a disease of adults up to middle age. Unlike most specific fevers. one attack does not confer immunity, but rather predisposes to others. Pneumonia begins with a chill. high fever, and a severe pain in the side, attributable to the accompanying pleurisy. As the malady progresses. there is a cough. with a viseid. air less, rusty sputum, later becoming yellow. Respi rations are rapid and shallow, 40 or 50 to the min ute: the pulse is also rapid, the cheeks flushed, and the general prostration extreme. There are in addition headache. sleeplessness, and sometimes delirium. These symptoms continue with more or fps. severity until the crisis oevurs, from the fifth to the eleventh day. when the temperature falls quite suddenly. almost to normal. and rapid improvement sets in. In a few eases a crisis does not occur, but the temperature declines gradu ally. Death takes place in fatal cases from heart failure, due to toxemia. During the prog ress of pneumonia, the affected portion of the lung goes through three stages. In the first or stage of by premiss the lung is congested, has a reddish brown color. and there is a slight exuda tion into the air cells. It is heavier than normal and contains less air. This stage lasts from one to three days. and is followed by the stage of exudation or red hepatization. In this the lung is red I resembling, when cut into, a section of livers, sinks in water, and the air sacs are com pletely filled with viscid, fibrinous fluid mixed with blood corpuscles. In from three to seven days the stage of resolution or gray hepatization sets in. The exudate filling the alveoli now un dergoes liquefaction and is partly al sorbed and partly expelled by acts of expectoration. This stage may endure from one to three weeks. Some times resolution is delayed, the exuded material undergoes purulent transformation, and single or multiple abscesses of the lung result. Pneumonia is a self-limited disease, and treatment is there fore not directed toward cutting short an attack, but toward keeping up the patient's strength, supporting the heart. and reducing the tempera
ture. It is particularly in the second stage that the patient is in danger, when the fever is at its height and the heart embarrassed. Alcohol, strychnine, and strophanthus are the most useful cardiac stimulants, and cold sponging and cold packs or haths the usual methods of mincing the fever. During the third stage expectorants are exhibited to assist in bringing up the exudate, and during convalescence tonics are given to build up the strength and restore the wasted tissues.
Bronchopneumonia (catarrhal or lobular pneu monia) attacks principally young children and old people by an extension downward of a bron chitis. It often occurs as a complication of the eruptive fevers, especially measles, and of whoop ing-cough. The disease affects the mucous mem brane lining the finer bronchial tubes (whence it has been called capillary bronchitis) and the air cells. These become blocked up by a yellow ish nmeoid material and larger or smaller por tions of the lung are deprived of air. The symp toms of this variety of pneumonia are similar to those of the croupous form, except that the tem perature rises more gradually and the rapidity of respiration is out of all proportion to the amount of tissue involved. The disease may be acute, subacute, or chronic in its course, and nearly one-half of the cases die. The treatment is designed, as in croupous pneumonia, to keep up the strength, and assist in the expectoration of the toxic material. A steam kettle is kept going in the sick-room, poultices are applied to the chest, and expectorants and a nourishing liquid diet are given throughout the attack.
Chronic interstitial pneumonia (eirrhosis of the lung) is a comparatively rare disease, found in miners. stone-cutters, grinders, and others whose occupation necessitates the inhalation of irri tating particles. It sometimes follows acute pneumonia in which resolution has been delayed, and generally terminates as a tuberculous pro cess. There is an overgrowth of the fibrous framework of the lung at the expense of the re spiratory elements. The organ shrinks some times to half its normal size, and is heavy and tough in consistence. There is always an asso ciated chronic bronchitis, with cough and ex pectoration. The course of the disease is slow, extending over ten or fifteen years. The treat ment of this disease consists in placing the pa tient under the best possible hygienic and cli matic conditions—a warm climate in the winter and a bracing one in the summer, with the ad ministration of tonics, such as cod-liver oil, iron, and quinine.
Among animals the horse perhaps most fre quently exhibits symptoms characteristic of pneumonia. Bail ventilation, improper attention to the needs of the animal. etc., are frequent causes. Remedies are similar to those used for the human subject.