Causes, pneumonia, extra force of right heart or weakness of left,
insufficiency of mitral valves, deflection of blood by obstruction in
one portion of lung, pressure of tumor on pulmonary veins. Malignant
œdema. Malignant catarrh. Bright’s disease. Anæmia. Parasitism.
Symptoms, abnormal heart sound, or urinary secretion. Parasitism.
Percussion shows flat sound auscultation lowered, respiratory murmur,
heightened blowing. No crepitation. Expectoration serous. Prognosis
grave. Treatment, attacks primary disease. Posture. Elimination. Dry
capping. Heart tonic.
A dropsy of the lung tissue may supervene in weak conditions, in the
course of inflammatory disease of the lungs; it may also depend on an
imperfect balance in the forces of the right and left heart
respectively, which leads to the habitual throwing of blood pressure
back upon the lungs. Still more frequently the congestion and dropsy
depends on insufficiency of the mitral valves by reason of which a
reflux of blood toward the lungs takes place at each heart beat. The
pressure of tumors on the pulmonary veins may have a similar action.
Obstruction of circulation in one portion of lung may cause an extra
blood pressure on an adjacent one, and œdema so caused may be found
especially in cattle and pigs in which the interlobular connective
tissue is specially abundant. This may be seen in miliary tuberculosis
in cattle, and it probably contributes to produce the extraordinary
liquid collections that characterize lung plague. In cattle also
malignant œdema may affect the lung, and an œdematous condition is
sometimes met with in malignant catarrh. Bright’s disease is another
cause, the uræmic dropsy finding a favorite seat of election in the
loose lung tissue unsupported by solid tissues. The anæmia resulting
from parasitism like distomatosis may similarly affect the lung.
The _symptoms_ of pulmonary œdema will usually be complicated by those
of the affection causing it. Thus modification of the first heart sound
or of the urinary secretion, or the existence of parasitism, would
furnish valuable indications.
The _physical signs_ of lung disease vary. If pneumonia is present it is
betrayed by its characteristic symptoms. In the absence of inflammation
there is dullness on percussion over the affected area, and on
auscultation an absence of the respiratory murmur, and perhaps abnormal
clearness of bronchial, cardiac and other sounds from deeper parts. It
differs from pneumonia in the absence of fever and of any crepitation
surrounding the consolidated portion. The expectoration is serous or
watery, rather than rusty or purulent.
The _prognosis_ is always grave in proportion to the incurable nature of
the primary disease. Chronic valvular or Bright’s disease, miliary
tuberculosis or malignant tumors would render the case hopeless, while
in acute pneumonia, or nephritis or parasitism there may be some hope.
The _treatment_ will largely consist in the therapeutics of the primary
disease, yet we may also seek to relieve the dangerous symptoms of
œdema. The frequent change of position may serve to limit hypostatic
accumulation. Diuretics or purgatives in strong patients will favor
absorption. Pilocarpin more than any other agent secures temporary
absorption but cannot be continued owing to its depressing effects.
Digitalis is often valuable in improving the heart’s action, and acting
freely on the kidneys. Dry capping on the chest acts as a derivative.