The second point, the prevention of infection, is readily attended to. The external wound must be thoroughly irri gated with boiled water, normal salt lution, or even unboiled, clean water, if nothing else is to be had, and sutured tightly in layers, if small: in any case covered with an aseptic dressing. tio strong antiseptics may be allowed about the wound, lest they leak into the pleura and there prove irritating.
As the case progresses two indications for drawing off the fluid from the chest may arise,—a progressive rise of tem perature, namely, and increasing dysp mea,--the one indicating infection, the other pressure. Paracentesis, the origi nal wound being left undisturbed, is the best way to meet either indication. If the quantity of fluid is large it should be drawn off, a pint at a time, at several sittings. Moreover the operation should be deferred as much as possible, for within the first eight or ten days there is danger of secondary hinmorrhage if the lung is relieved of the pressure upon it. When the fluid withdrawn from the pleura contains bacteria no more than temporary relief from infection may be expected, and as soon as the tempera ture begins to ascend again permanent drainage must be established either by reopening the old wound or making a new one (see EMPYEMA). But when the fluid is aseptic and the fever continues in spite of paracentesis the inflammation is presumably confined to the lung. Yet it must not be forgotten that empyema may occur even after the pleura has been emptied.
If at the end of twenty days there is still fluid in the pleural cavity para centesis should be performed.
Pneumothorax.
—The symptoms are quite the same whether the pneumothorax is traumatic or "spontaneous": i.e., caused by the rupture of a tubercular cavity into the pleura. There is a sudden, sharp pain in the chest, followed by col lapse, more or less severe. Even though the shock be slight, the respiration and pulse are irregular and feeble. The af fected side moves little or not at all with respiration. The heart is displaced toward the sound side. fremitus is diminished or absent, and the per cussion-note usually tympanitic or am phoric. The voice and breathing are cavernous, amphoric, or absent. If the external wound is patent there is "trau matopncea": i.e., breathing through the wound.
pneumotho rax is exceedingly rare. There is usually serum, pus, or blood in the pleura as well as the fluid. In trau matic cases the condition is practically always one of hmmopneumothorax. The signs of hfemothorax may be obtained in the lower part of the pleura, the signs of pneumothorax above, and such spe cial signs as succussion and metallic tinkle between the two (less clearly in hoemopneumothorax than in hydropneu mothorax).
Subcutaneous emphysema is rather an associated condition than a complica tion.
-Pneumothorax, like by drothorax, is produced by the elasticity of the lung, which tends to retract upon itself toward its hilum as the air rushes into the pleura. In traumatic cases the pleura is usually free from adhesions and the pneumothorax a complete one. the empty lung being surrounded on all sides by air. The loss' of the use of one lung and the upset in the equilibrium of thoracic pressure accounts for the marked disturbance of pulse and breath ing.
If the opening into the pleura, whether pulmonary or parietal, heals. the lung expands as the air in the pleu ral cavity is absorbed. If the opening does not heal, the lung expands more slowly by a species of capillary adhesion to the parietal pleura, aided by the vary ing intrapulmonary pressure of respira tion.
—An uncomplicated pneu mothorax usually progresses toward re covery without accident. Death may, however, occur from the initial shock or from the associated haemothorax, and the favorable progress may be inter rupted by the occurrence of subcutane ous emphysema or dyspiacea, indicative of pressure. Suppuration is rare.
-Pneumothorax usually requires no special treatment. To re lieve pressure or to prevent progressive emphysema paracentesis or drainage may be resorted to.
In pneumothorax the importance of respiratory quietude and the advantage of removing the gas under the same cir cumstances as one would a liquid effu sion are insisted upon. Foxwell (Brit. Med. Jour., Apr. 25, '96).
The best treatment of pnemnothorax is by means of a tube or cannula with a valve opening only from within outward. By this means air issues only during ex piration, and none enters the pleural cavity during inspiration; hence the air is gradually removed. This method of treating pneumothorax is not only safer than thoracentesis, but more efficacious. D'Alessandro (G'az. degli Osp. e delle Clin., Feb. 7, '97).
Thirteen cases of empyema and pneu mothorax treated by permanent drain age. Five cases were cured, 6 died, and 2, the latter tuberculous, improved, but subsequently showed amyloid degenera tion. The appearance of foetid pus re quires immediate thoracotomy. Perma nent drainage is most valuable in recent cases, though it is often successful in the latter forms. K. Pitchler (Deut. Arch. f. klin. Med., Dec. 22, '97).
Subcutaneous Emphysema. — Subcu taneous emphysema appears as an ill defined oedematous swelling which pits 'under pressure, imparting to the finger a fine crackling sensation.
After rupture of the lung it rarely ap pears unless there is pneumothorax. The emphysema first appears at the root of the neck about the trachea and great vessels, reaching there along the bron chi, trachea, and vessels from the pleura.
It also infiltrates the tissues about any wround in the parietal pleura.
After wounds of the lung there is often an infiltration of air about the ex ternal wound, and this is especially liable to occur if the wound is small or roughly sutured so that the air may, by the variations of intrathoracic pressure, be forced into the deeper tissues, but not through the skin.
Subcutaneous emphysema is rarely a matter of any moment. It is usually slight in extent and quickly absorbed. It rarely ends in suppuration. But if the laceration in the lung acts in a valvu lar manner, pumping air into the lung with each inspiration and allowing none to escape with expiration, the emphy sema may spread over all the thorax, even over the whole body, in which case the danger is from suffocation. The treatment is multiple incisions. At the same time the intrathoracic pressure must be relieved by paracentesis or drainage.