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See also:PLEURISY, or PLEURITIS (Gr. srXeiipc =ribs)
, inflammation of the pleura, caused by invasion by certain specific micro-organisms
.
(See See also:RESPIRATORY See also:SYSTEM: See also:Pathology.) Secondary pleurisies may occur from See also:extension of inflammation from neighbouring See also:organs
.
The morbid changes which the pleura undergoes when inflamed consist of three See also:chief conditions or stages of progress
.
(I) Inflammatory congestion and infiltration of the pleura, which may spread to the tissues of the See also:lung on the one See also:hand, and to those of the See also:chest See also:wall on the other
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(2) Exudation of See also:lymph on the pleural surfaces
.
This lymph is of variable consistence, some-times composed of thin and easily separated pellicles, or of extensive thick masses or strata, or again showing itself in the See also:form of a tough membrane
.
It is of greyish-yellow See also:colour, and microscopically consists mainly of coagulated See also:fibrin along with See also:epithelial cells and red and See also: (1) Some pleurisies do not reach the See also:stage of effusion, the inflammation terminating in the exudation of lymph . This is termed dry pleurisy . (2) Fibrinous or plastic pleurisy . In this variety the pleura is covered by a thick layer of granular, fibrinous material . Fibrinous pleurisy is usually secondary to acute diseases of the lung such as See also:pneumonia, See also:cancer, See also:abscess or See also:tuberculosis . (3) Sero-fibrinous pleurisy . This is the most See also:common variety, and produces the See also:condition commonly known as pleurisy with effusion . The amount may vary from analmost inappreciable quantity to a See also:gallon or more . When large in quantity it may fill to distension the pleural sac, bulge out the thoracic wall- externally, and compress the Iung, which may in such cases have all its See also:air displaced and be reduced to a See also:mere fraction of its natural bulk . Other organs, such as the See also:heart and See also:liver, may in consequence of the presence of the fluid be shifted away from their normal positicn . In favourable cases the fluid is absorbed more or Iess completely and the pleural surfaces again may unite by adhesions; or, all traces of inflammatory products having disappeared, the pleura may be restored to its normal condition . When the fluid is not speedily absorbed it may remain See also:long in the cavity and compress the lung to such a degree as to render it incapable of re-expansion as the effusion passes slowly away . The consequence is that the chest wall falls in, the ribs become approximated, the See also:shoulder is lowered, the spine becomes curved and See also:internal organs permanently displaced, while the affected See also:side scarcely moves in respiration . Sometimes the unabsorbed fluid becomes purulent, and an See also:empyema is the result . The symptoms of pleurisy vary; the onset is sometimes obscure but usually well marked . It may be ushered in by rigors, See also:fever and a See also:sharp See also:pain in the side, especially on breathing . Pain is See also:felt in the side or See also:breast, of a severe cutting See also:character, referred usually to the neighbourhood of the nipple, but it may be also at some distance from the affected See also:part, such as through the See also:middle of the See also:body or in the abdominal or iliac regions . On See also:auscultation the physician recognizes sooner or later " See also:friction," a superficial rough rubbing See also:sound, occurring only with the respiratory acts and ceasing when the breath is held . It is due to the coming together during respiration of the two pleural surfaces which are roughened by the exuded lymph . The pain is greatest at the outset, and tends to abate as the effusion takes place . A dry cough is almost always See also:present, which is particularly distressing owing to the increased pain the effort excites . At the outset there may be dyspnoea, due to fever and pain; later it may result from See also:compression of the lung . On See also:physical examination of the chest the following are among the chief points observed: (I) On inspection there is more or less bulging of the side affected, should effusion be present, obliteration of the intercostal spaces, and sometimes See also:elevation of the shoulder . (2) On palpation with the hand applied to the side there is diminished expansion of one-See also:half of the See also:thorax, and the normal vocal fremitus is abolished . Should the effusion be on the right side and copious, the liver may be felt to have been pushed downwards, and the heart somewhat displaced to the See also:left; while if the effusion be on the left side the heart is displaced to the right . (3) On percussion there is See also:absolute dullness over the seat of the effusion . If the fluid does not fill the pleural sac the floating lung may yield a hyper-resonant See also:note . (4) On auscultation the natural breath sound is inaudible over the effusion . Should the latter be only partial the breathing is clear and somewhat harsh, with or without friction, and the See also:voice sound is aegophonic . Posteriorly there may be heard tubular breathing with aegophony . These various physical signs render it impossible to See also:mistake the disease for other maladies the symptoms of which may See also:bear a resemblance to it, such as pleurodynia . The absorption or removal of the fluid is marked by the disappearance or diminution of the above-mentioned physical signs, except that of percussion dullness, which may last a long See also:time, and is probably due in part to the thickened pleura . Friction may again be heard as the fluid passes away and the two pleural surfaces come together . The displaced organs are restored to their position, and the compressed lung re-See also:expanded . Frequently this expansion is only partial . In most instances the termination is favourable, the acute symptoms subsiding and the fluid (if not See also:drawn off) becoming absorbed, sometimes after reaccumulation .
On the other hand it may remain long without undergoing much See also:change, and thus a condition of chronic pleurisy becomes established
.
Pleurisy may exist in a latent form, the patient going.about for See also:weeks with a large See also:accumulation of fluid in his thorax, the
See also:ordinary acute symptoms never having been present in any See also:Zealand and See also:Tasmania received it in 1864, but it was eradicated in both countries by the sanitary See also:measures adopted
.
It was carried to See also:Asia See also:Minor, and made its presence felt at See also:Damascus
.
It prevails in various parts of See also:China, See also:India, See also:Africa and See also:Australia, and until quite recently it existed in every See also:country in See also:Europe, except Scandinavia, See also:
The usual seat of inoculation is the extremity of the tail, the See also:virus being introduced beneath the skin by means of a See also:syringe or a worsted See also:thread impregnated with the lymph
.
See also:Protection against infection can also be secured by subcutaneous or intravenous injection of a culture of Arloing's pneumo-bacillus on See also: |
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