Catarrhal pneumonia never originates primarily in the alveoli, unless it be brought on by an irritant, such as chlorine, for instance, when an inflammation may arise in the alveoli and the bronchi simultaneously; otherwise it is always a secondary morbid process to bronchitis, which compare. For this reason it has received the name of Bronchopneumonia; and as the inflammatory process presents itself at first in isolated nodules, from the size of a pea to that of a hazel-nut within the collapsed portions of the lung tissue which still contains isolated portions accessible to air, it has also been named Lobular pneumonia. This morbid process may diffuse all over the lungs in the form of isolated infiltrations, and usually progresses from behind and below, forwards and upwards.
According to all observations its most frequent occurrence is found in the first three years of life, and those of old age, and as indirect causes we may set down all disturbances that favor the development of bronchial catarrh — such as, measles, whooping-cough, diphtheria, influenza, rotheln, sometimes typhus, variola and scarlatina; also foreign bodies in the bronchi and inhalation of gases.
It presents no regular type of fever; the physical diagnosis is of great difficulty. We must mainly rely on the presence of a capillary bronchitis; on the consolidation of the lung, beginning at its base, arising slowly, at first without any prominent signs and mostly bilateral; on the retraction of the lower ribs seen during inspiration; on the indefinite limitation of the disease, the absence of all critical periods and the fluctuations which occur in general and local symptoms.
THERAPEUTIC HINTS — Compare Bronchitis and Croupous Pneumonia.
Serous pneumonia, see Oedema of the lungs.
Pneumonia from embolism happens only in otherwise diseased persons. The emboli are formed either from clots which have originated in the cavities of the right side of the heart, or in the veins of the systemic circulation. In the first place there is disease of the heart, and in the latter their sources are either large external wounds, venous thrombi of the uterus in puerperal women, or bed sores, ulcerations and suppurations of various kinds. When these plugs are non-infectious. They produce mere hemorrhagic infarction. When they are of an infectious nature, they result in embolic or metastatic abscesses, which may perforate into the bronchi, or into the pleural cavity, or even break through the chest walls. Simple infarctions are often accompanied with an effusion into the pleural sac, and are much oftener found in the right lung than in the left.
Croupous pneumonia, is that form which is commonly meant by the term “pneumonia,” and consists of an acute inflammation of the alveoli and bronchioles in which a fibrinous exudation is poured out upon the free surface of the mucous membrane, and there coagulates. It attacks in preference the inferior lobes of the lungs, especially on the right side; very rarely both lungs at the same time. It very rarely pervades one whole lung, being much oftener confined to limited portions, which may even be too small to be detected by percussion. It is also of rare occurrence that the inflammation remains confined to a central portion of a lobe only, (central pneumonia) but generally spreads to the surface of the lobe which joins the pleura.
In aged persons and cachectic individuals the posterior parts of the lungs are most frequently attacked. When normally progressing, pneumonia offers three distinct stages for consideration:
1. The inflammatory stage or hyperemia of the capillaries in the lung tissue with exudation of coagulable lymph.
2. Hepatization, or infiltration of the lung tissue with coagulable lymph.
3. Its resolution, or purulent infiltration.
The characteristic signs of these different stages are as follows:
First stage : As a general thing the disease sets in with a violent chill, often attended with vomiting and followed by an intense fever, with a temperature of 104 to 105 in the evening and from 0.9° to 2.7° less in the morning; the pulse rises to 100 or 110 and the respiration to 40 or 50 per minute. In other cases the disease sets in with several light chills or chilliness, or the chill is entirely absent and the scene opens with convulsions and complete loss of consciousness. The skin is at first very dry, but becomes moist usually about the third day, though only temporarily. The face is purplish-red, and frequently only on that side which corresponds to the diseased side of the lungs. The lips become covered with hidroa, (fever blisters) arid also very often only on the affected side, or, at least, more marked on that side. The alae nasi make corresponding movements with respiration. The voice of the patient is low and he speaks in broken sentences.
Cough is, in almost all cases, present, although in some less marked than in others. The patient generally tries to suppress it, on account of the pain which it gives. At first it is dry, but after a time it yields a tough, jelly-like, viscid sputum, difficult to expectorate, and adhering to the lips, from which it has to be wiped off; it soon changes to the characteristic color of rust, from an admixture of blood.
When the patient complains during the coughing spells of stitching pain in the chest, it is more or less a sign that the pleura participates in the morbid process; when he complains of dull, heavy pains, they probably originate in the bronchial tubes. In consequence of the disturbed circulation through the lungs, the blood being either not sufficiently oxygenized, or being prevented from or retarded in its return from the brain, different brain symptoms originate, such as delirium, stupor, etc., so that the case may take the appearance of typhoid fever, from which it is easily distinguished by the hidroa on the lips, which are scarcely ever found in typhoid fever.
In rare cases we observe jaundice combining with pneumonia. In such cases the liver appears enlarged on account of the engorgement which is brought about by the impeded circulation. As the hepatic veins cross the gall-ducts the latter become compressed and the gall retained. In other cases it seems that pneumonia is complicated with a parenchymatous inflammation of the liver, or a catarrh of the duodenum, causing in either case, icterus.
The urine is scanty and concentrated, and deposits, on cooling, a sediment of brick-dust urates. The bowels are usually constipated. The Physical Signs at this stage are the following :
Inspection discovers decreased mobility of the diseased side of the thorax. In cases where both the lower lobes are engorged, the patient moves only the upper part of the thorax in breathing, whilst the abdomen remains quiet on account of the impossibility to retract the diaphragm.
Palpation shows an increased vocal fremitus, unless the bronchial tubes should be stopped up by mucus. The impulse of the heart is also increased, but felt in its normal position. Percussion yields generally a short, tympanitic sound over the parts involved, as long as they still contain air. Auscultation reveals the crepitant sound which, according to Wintrich, arises in consequence of the sticking together of the walls of the air-cells, and their separation by inspiration.
Second stage, hepatization. The above-mentioned symptoms — fever heat, dyspnea, cough, pain, and brain symptoms continue. The thorax appears, on inspection, still less movable during respiration ; the vocal fremitus is strong, provided there does not intervene a pleuritic effusion between the hepatized lung and the thoracic wall. Percussion gives forth a dull sound, and the resistance of the thoracic walls to the percussing finger is increased, provided the hepatized portion of the lung have the thickness of about one inch, and a superficial extent of several inches. A central location of the hepatization alters the percussion sound very little, on account of the intervening portion of lung containing air.
Auscultation yields neither the natural vesicular breathing, nor the crepitant sound of the first stage, but bronchial breathing, bronchophony, and even pectoriloquy, provided the bronchial tubes, which are contained in the hepatized portion of the lung, be not stopped by mucus, blood-coagula, etc. There are also heard all sorts of rattling noises, if mucus exists in the bronchial tubes.
Third stage, resolution. This sets in sometimes with a sudden relaxation of all the violent symptoms — the temperature falls in from 12 to 36 hours to the normal, and at times even below the normal; the congested, even purplish face becomes pale, the skin moist, the dyspnoea ceases, the sputa become copious, frothy, yellowish, easily expectorated; the urine increases and becomes natural again.
On inspection, we observe that the thoracic walls regain their natural mobility; the percussion sound again becomes tympanitic, and by means of auscultation we observe the bronchial breathing and bronchophony becoming weaker; the crepitation sound reappears, until, at length, the natural vesicular respiration is re-established. This is the regular progress of simple pneumonia, lasting, on an average, from fourteen to twenty-five days, of which two, three, or five days are consumed by its first development, five to eight days by exudation progressing to perfect hepatization, and seven to fourteen days by the resorption of the exudation and convalescence.