The chronic form of the disease is more common than the acute. It
seems probable that many cases of pulmonary tuberculosis are due to
inhalation of the tubercle bacillus, though no doubt, particularly in
children the bacillus frequently gains entrance to the system through
the intestinal tract from infected milk and food. =Deformities= of the
chest, especially where there is constriction and rigidness of the
upper part, with more or less immobility of the first, second and third
ribs and the junction of the manubrium and gladiolus, associated with
weak muscles and a stooped posture are definite predisposing factors.
This condition may be congenital or acquired. The local innervation,
blood supply and lymphatic drainage is involved, so that the individual
is less resistant and consequently susceptible to infection. The
bronchi are thus weakened, favoring the infectious process so that
the disease may advance and involve the neighboring tissues, or if
infection has gained entrance to the lymph or blood stream elsewhere,
the susceptible pulmonary organs may become diseased.
Owing to the above predisposing factors the =primary lesion= of the
lungs is often in the bronchus a little below the apex near to the
posterior and external borders. A lower lobe may be involved, or
several lesions may occur at the same time, involving one or both
lungs. Frequently the other lung is infected from the lesion or lesions
of the first.
In the acute cases the exudative process involves the lung tissue,
becomes caseous and softened, and later necrotic with cavity formation.
In the =chronic type= the exudative process is slower, with thickening
of the walls of the air vesicles and increase of fibrous tissue.
=Cavities=, the result of caseation, are of various size, ragged,
often coalesce and open into the bronchus. Fibrous tissue forms about
them and frequently arrest the process. In the necrotic involvement
blood vessels are often injured causing hemorrhages. Pleurisy,
empyema, catarrhal bronchitis, and bronchiectasis are often associated
involvements.
In addition to the tubercle bacillus, other micro-organisms,
streptococcus and staphylococcus pyogenes, influenza bacillus, and
diplococcus pneumoniæ, are often found, and no doubt are important
exciting factors.
The =bronchial glands= are swollen, and contain tubercles. They may
undergo purulent disintegration. Tuberculosis of the =larynx= is
common. In severe cases there may be amyloid changes of =liver=,
=kidneys=, spleen, and mucous membrane of the intestines. Tuberculous
lesions are found in the intestines, spleen, kidneys, and brain in
nearly equal proportions; then come the liver and pericardium.
=Symptoms.=—The onset of the disease is either abrupt or gradual.
Frequently it succeeds influenza, measles, or bronchitis. There is
a cough, expectoration, loss of weight, afternoon temperature and
probably night sweats. The disease is likely to develop slowly. In
other cases gastro-intestinal disorders are the first symptoms,
especially with weakness and debility. Again, the disease may follow
pleurisy. When the attack is abrupt, pneumonia is simulated. However,
the apex of the lung, instead of the middle or lower lobe, is involved;
expectoration is considerable and the fever is not so high and
pronounced. Hemoptysis frequently occurs.
The =local symptoms= are important. =Pain= is an early either moderate
or severe, symptom, although there are cases where it is absent. When
associated with pleurisy, it is severe. The pain is usually situated at
the base, anteriorly or laterally, of the scapulæ, but may be between
them. =Cough= is present, in the majority of cases, throughout the
entire course. It usually grows worse, and is dry and hacking at the
beginning but looser and paroxysmal and accompanied by a mucopurulent
expectoration later on. The =expectoration=, at first, is slight and
there may be more or less blood mixed with it, or even hemorrhage may
occur. With the formation of cavities, the expectoration increases
and is of a greenish-gray or greenish yellow color. In some instance
the sputum is more or less fetid. The expectoration is composed of
pus cells, blood, elastic tissue, fat globules and tubercle bacilli.
=Hemoptysis= is present in a majority of cases. Early hemorrhages
are usually slight, due to rupture of weakened vessels. When there is
softening or cavity formation, erosion of vessels may be pronounced
and hemorrhage considerable. Dyspnea is a variable symptom, but is
characteristic of lung changes.
=Fever= is a characteristic symptom. It is probably always present at
the beginning and the afternoon increase of temperature is common.
Where there is softening and formation of cavities, a remittent or
intermittent type is present. The pulse is frequent, regular and
compressible. =Sweats= may occur at any time, but especially during
sleep. They indicate fever activity, and are increased during cavity
formation. =Emaciation= is a prominent symptom. This is due to
gastro-intestinal disorders and prolonged fever. Loss of weight is
gradual, especially if the disease is advancing. Where the lung is
considerably diseased, heart disturbances are common.
Other disorders, as of the gastro-intestinal tract, genito-urinary,
cutaneous, and nervous systems, are frequent, especially in long
standing cases. The =gastro-intestinal disturbances= are gastric
catarrh, vomiting, loss of appetite, coated tongue, constipation, and
later on, diarrhea. Among =genito-urinary symptoms=, albuminuria is
frequent. The kidney involvement may be either of an acute or chronic
character. Pyelitis and cystitis are present in some cases, and amyloid
degenerations are not uncommon. With the =cutaneous symptoms=, the
skin is frequently dry and scaly, and the hair of the head dry. The
hectic flush is common. Upon the chest and back there may be pigmentary
stains. The =nervous symptoms= vary according to the involvement.
Tuberculous meningitis is rare. The mind usually is clear and even in
advanced stages the patient is always hopeful.
=Physical Signs.=—=Inspection= reveals that the shape of the chest
is often characteristic. A phthisical thorax is flat, especially
the thoracic opening with wide intercostal spaces, prominent costal
cartilages, and depressed sternum. Sometimes the lower sternum forms
a deep concavity (funnel breast). Another type of thorax is long
and narrow, with very oblique ribs, and little expansion. In other
instances the chest is of apparently normal build. Defective expansion
is observed early, especially at the apex of the affected side. The
clavicle of the affected side often stands out more prominently.
=Palpation= shows there is decreased expansion and increased fremitus.
Normally, the fremitus is stronger at the right than at the left apex.
If the pleura is thickened, the fremitus is decreased, but increased in
lung involvement.
On =percussion=, if the diseased areas are minute, the percussion
note may not be changed. Always compare the two sides of the chest.
Dullness is first noted, as a rule, above, on or below the clavicle.
As the disease progresses, the dull sound increases. The size of the
cavity, its walls and the amount of secretion modify the note. Large,
thin-walled cavities elicit the “cracked-pot” sound. Consolidation,
thickened pleura, large amount of material in a cavity and a connecting
bronchus impair resonance.
On =auscultation= the breathing is harsh and the expiration is
prolonged and high-pitched (bronchial). Early in the disease crackling
rales may be heard. After consolidation takes place there is bronchial
breathing and crepitant rales. When softening occurs they become moist,
louder and sometimes bubbling. These may be heard upon inspiration and
expiration. Pleuritic friction sounds, as in case of pleurisy, may be
heard at any stage. Vocal resonance is increased.
The =signs= of =cavity= are: =Percussion.=—There is more or less
defective resonance or tympany. Over large cavities a “cracked-pot”
resonance is obtained. This is best obtained when the patient has his
mouth open. There may be normal resonance if the cavities are covered
with a considerable thickness of unaffected air cells.
=Auscultation= may detect cavernous or amphoric breathing, pectoriloquy
and coarse, bubbling rales. Metallic tinkling may be heard over large
cavities. Vocal resonance is increased.
=Complications.=—The larynx and trachea frequently undergo tubercular
inflammation, due to invasion from the lung tissue. Pneumonia is of
common occurrence. Gangrene, pleurisy and endocarditis are other
complications.
=Diagnosis.=—Bacilli may be found in the sputum before the physical
signs are well developed. It may be necessary to examine the sputum
several times before the tubercle bacilli are detected. The presence of
bacilli will set the diagnosis at rest, provided clinical symptoms are
present. Fever, hemoptysis, cough, emaciation and a continuous, local
induration are diagnostic. The X-ray should be employed as an aid in
diagnosis.
=Prognosis.=—The prognosis of pulmonary tuberculosis varies greatly in
different cases. Undoubtedly a number of cases have been cured; many
arrested; even spontaneous cures have occurred. A great deal can be
done to prolong life and to make the patient comfortable. The average
duration is about three years, although by careful treatment this time
is probably being increased.