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Liquid in a pleural cavity accumulates or owing to damage of the pleura covering it, or in connection with the general disturbances of a water and electrolytic exchange in an organism. The first arises at the inflammations of a pleura caused by causative agents of infectious diseases at defeat by its neoplastic processes, infiltratsiy adenoid or myeloid tissue. The second is quite often observed at an injury, a scurvy, at the diseases which are complicated by heart failure, a nephrotic syndrome and at some other diseases (see the appendix).
The differential diagnosis of the accumulated liquid in a pleural cavity can be subdivided into two stages. In the beginning identification of a syndrome, i.e. its difference from other syndromes with similar clinical signs then its reason becomes clear is made.
Identification of a syndrome of liquid in a pleural cavity
Physical signs of accumulation of liquid in a pleural cavity are well-known. At the expressed its accumulation percussion on a back surface of a thorax reveals three zones on acoustic properties. Over a top of lungs is defined clear pulmonary, and over its basis — a stupid sound. Between them the zone of a tympanic percussion sound is defined. The tympanites is caused by a partial atelectasis of the lung which lost considerably the tension.
Voice trembling over a zone of a stupid percussion sound is weakened or is not defined. Over a zone of absolute dullness respiratory noise are not defined or are weakened. Over a zone of a tympanic percussion sound the weakened bronchial breath is listened, as a rule. Vesicular breath is defined over a zone of a clear pulmonary sound.
Despite considerable number of episemes, the diagnosis of a syndrome of liquid in a pleural cavity quite often causes doubts which most part disappears after X-ray inspection. It is better to make trial (diagnostic) function of a pleural cavity after X-ray inspection. She allows to confirm availability of liquid in a pleural cavity and to define its character. Especially often additional researches should be made for difference of a syndrome of liquid in a pleural cavity from pneumonia, a tumor of the slight and some other diseases and syndromes listed in the appendix.
Share or drain focal pneumonia sometimes is accepted to accumulation of liquid in a pleural cavity. It is especially easy to make this mistake at a bed of patients with the pneumonia which joined flu. The severe damage of a mucous membrane of bronchial tubes at flu and some other infectious diseases of lungs leads sometimes to almost full obturation of the bronchial tube draining the struck segment of lungs. Thereof over the struck segment or a lung lobe the percussion sound becomes stupid, and breath sharply weakened. It some time can sometimes be inaudible.
The correct diagnosis manages to be made, having paid attention to limits of dullness. A zone of a stupid percussion sound at pneumonia: matches a projection of a share and lung lobes to a thorax surface. The upper bound of dullness of a percussion sound at accumulation of liquid in a pleural cavity forms the line of Damuazo which dome is on the axillary line. We had to be convinced of advantage of definition in similar cases of triangles of Garland and Raukhfus more than once. Simultaneous definition of zones stupid, tympanic and clear pulmonary sounds, and also zones of the weakened breath corresponding to them and breath with a bronchial shade considerably facilitated the differential diagnosis of pneumonia from accumulation of liquid in a pleural cavity.
Accumulation of liquid in a pleural cavity sometimes is taken for pneumonia. It is observed when over area of absolute dullness bronchial breath is listened. It occurs quite often at children at the extensive exudates which are completely squeezing a lung. Heart in similar cases is displaced aside, opposite to exudate. At pneumonia heart, as we know, is not displaced. Cough can be observed at both diseases, but cough at pneumonia is followed by expectoration whereas at exudates in a pleural cavity it is dry. The differential diagnosis is considerably facilitated by the analysis of other extra pulmonary symptoms of an illness, such as character of fever, expressiveness of a leukocytosis, order of emergence separate, symptoms of an illness. In comparison to data of X-ray inspection the specified signs allow to make the correct diagnosis of a syndrome.
Extensive shvarta give a dullness and a shadow on the roentgenogram which are sometimes difficult for distinguishing from similar signs at accumulation of liquid in a pleural cavity. It is quite often noted as well disturbance of the normal respiratory excursions of a diaphragm caused by unions and commissures. The compared syndromes differ from each other on character of shift of heart. Heart at extensive exudates is displaced in healthy side of a thorax, and at big pleural unions — in struck. Besides, at shvarta respiratory noise, despite dullness, reach clearly, and at accumulations of liquid in a pleural cavity they are considerably weakened. The zone of a tympanic sound is defined only at a liquid syndrome in a pleural cavity.
The dullness and the weakened breath constantly arise over an atelectasis zone which develops in connection with a stenosis or obturation of a bronchial tube a tumor. Bodies of a mediastinum at an atelectasis are displaced in the struck party whereas liquid in a pleural cavity displaces them to the opposite side. The radiological method of research allows to catch the broken bronchial passability long before emergence of physical signs of an atelectasis. We had to meet big tumors of a mediastinum which squeezed an upper share and, causing its atelectasis, led to emergence of a stupid percussion sound and weakening of respiratory noise. The combination of these signs is observed at big tumors of a lung. The stupid percussion sound and lack of respiratory noise are constant signs of a fibrothorax.
High standing of a diaphragm leads to sharp weakening of respiratory noise and a dullness over the lower lung lobe. The expressed increase of a dome of a diaphragm on the one hand constantly is observed at paresis of a phrenic nerve, primary cancer of a liver, liver abscesses, subphrenic abscess, a considerable gastrectasia, for example at a pyloric stenosis. Bilateral high standing of a diaphragm is among characteristic symptoms of obesity, the expressed meteorism. Results of physical research do not allow to distinguish accumulation of liquid in a pleural cavity from high standing of a diaphragm, but X-ray inspection of a lung distinguishes these syndromes from each other.
In some regions of Russia the echinococcal illness meets. When the echinococcal cyst is located in a thorax, it is found in the lower shares of lungs more often. The back department of the lower share of the right lung appears the favourite place of its localization. If the cyst prilezhit to a chest wall, a diaphragm or a bronchial tree, it is sometimes flattened. The percussion sound over a cyst surface always stupid, and breath either is not defined, or is sharply weakened. X-ray inspection reveals usually characteristic round cyst often with the calcification centers. The puncture of a cyst is contraindicated an ulcer of possible planting of a pleural cavity and lungs.
Availability of liquid in a pleural cavity has to be estimated as the indication to a thoracocentesis which is the most reliable way of clarification of an etiology of a syndrome. Pleural liquid can be divided into transsudata and exudates. To transudate liquid which collects in a pleural cavity in connection with the general disturbances of a water and electrolytic exchange in an organism, but not owing to a pleura inflammation belongs. Trassudata arise at cirrhosis, beriberi (deficit of B1 vitamin), at the hypoproteinemias caused by starvation, the increased losses of protein in a digestive tract gleam at heart failure, a nephrotic syndrome, heavy anemia. It is unconditional that each of the listed syndromes has a reason swap without which clarification the etiological diagnosis of a syndrome cannot be made. It is necessary to highlight that accumulation of transudate in a pleural cavity can be the only symptom of the latent heart or renal failure.
Inflammatory damages of a pleura are followed by formation of exudate which can be subdivided on serous, hemorrhagic, purulent, chyle. Following this traditional division, it must be kept in mind that hemorrhagic exudate differs from serous only in color of liquid and that chyle liquid accumulates in a pleural cavity in most cases out of communication with an inflammation of the pleura covering it. Accumulation of exudate appears sometimes the only symptom of an illness. Of this sort isolated exudates can be distinguished from the isolated transudate by outward, relative density and content of protein in them.
Exudates always opalestsirut, when standing form a clot; relative density exceeds them 1018, and protein content exceeds 30 g/l, often reaching 50 g/l. Transsudata are transparent, are not curtailed when standing, relative density is lower than them 1015, and protein content fluctuates usually from 5 to 15 g/l. Frequent intermediate figures in practical work are explained by coexistence of two processes, for example liquid transudation in a pleural cavity and inflammations of leaves of a pleura as it often occurs at a lung heart attack at the patient with heart failure. A certain diagnostic value has also cytologic composition of exudate, the maintenance in it of neutrophils, lymphocytes, erythrocytes, cells of a mesothelium and tumor cells.