A system of practical medicine. By American authors. Vol. 3

by Unknown

²⁴³ Loc. cit.

²⁴⁴ Loc. cit.

One of the most pronounced effects constantly observed in pneumothorax is the immediate displacement of the heart to a greater extent than in pleurisy. Gaidy,²⁴⁵ as far back as 1828, described displacement of the heart as an important sign of pneumothorax. He related a case where, at the moment of the perforation, the woman was conscious of the heart's beat having been transferred to the right of the sternum. Powell²⁴⁶ out of 17 cases found the heart displaced in 16: in the seventeenth the unruptured lung was so consolidated that it could not collapse. In pneumothorax of the right side a careful examination is sometimes required to detect the displacement of the heart. The apex can be discovered at a considerable distance to the left of the nipple, with the right ventricle drawn to the left edge of the sternum. It has been generally believed that the cause of this displacement was the intra-pleural pressure of the air, but this does not satisfactorily explain it, for there can be no pressure until the elasticity of the lung has been overcome. In 13 of Powell's cases there was great displacement of the heart with different degrees of intra-pleural pressure. In 3 cases there was great displacement of the heart with no intra-pleural pressure. The same author²⁴⁷ showed, experimentally, that the elastic tension of one lung, when unopposed by that of the other, was sufficient to draw aside the mediastinum, and with it the heart. He thus demonstrated that these displacements are by no means necessarily a sign of intra-pleural pressure, since they may occur to the right of the sternum without there being any pressure. Clinically, we know that the admission of air into the pleural cavity immediately and constantly displaces the heart, unless the opposite lung be consolidated or otherwise injured in its resiliency. This occurs even when the patent orifice of the perforation prevents the accumulation of any quantity of air. There is not enough air to produce direct pressure, but there is enough to impair the elastic traction of the lung, and thus to destroy the equilibrium of traction which keeps the heart in its normal position. The healthy lung by its unimpaired tractile force immediately draws over the heart. Skoda²⁴⁸ maintains that "air does not enter the pleural cavity simply at the cost of the torn and retracted lung, but the sound lung also retracts to such a degree as to move the mediastinum." Garland's experiments²⁴⁹ conclusively demonstrate that the air in pneumothorax is powerless to exert an appreciable lateral displacing force until the lung has completely collapsed; and this does not ordinarily occur. There can be, he says, but one cause of constant and early displacement of the heart—the elastic force of the opposing lung, which draws it over to itself. He adds that "the explanation of the greater displacement of the heart in pneumothorax is that the air, having practically no weight, cannot exert upon the heart the negative pressure which an effusion evidently would."

²⁴⁵ Arch. Gén. de Méd., tome xvii., 1828.

²⁴⁶ Medico-Chirurg. Trans., vol. lix.

²⁴⁷ British Med. Journal and Med. Times and Gazette, July, 1869.

²⁴⁸ Auscultation and Percussion, Eng. trans.

²⁴⁹ Loc. cit.

The fluid in hydro-pneumothorax is very rarely of a serous character. Saussier found but 1 such example in 169 cases. It is almost always purulent pneumothorax, and frequently it has a very offensive fetid odor from putrid decomposition. Mixed with pus there are sometimes found masses of pseudo-membranes, débris of lung, and gangrenous patches, as in purulent pleurisies. The fistulous orifice through which the air has entered is not always easily found, being often hid away among false membranes. It is small and tortuous, and can only be discovered by placing the lung under water and blowing air through the bronchial tubes. Sometimes the orifices close and the air becomes encysted, interlobular, or diaphragmatic. There is sometimes only one opening; again, there may be several. Nolais reports a case where there were six openings. Orifices with lacerated edges are met with, varying in length from one to ten or twelve centimeters. It must be borne in mind that perforation can take place without producing pneumothorax. Saussier found this occurred in 2 out of 74 cases, and in 8 out of 29 resulting from pleurisy. Fériol and Guéneau de Mussey give similar cases.

SYMPTOMS.—The initiatory symptoms of pneumothorax vary according to the cause which produces it. When the effusion of air into the pleural cavity is from perforation of a diseased lung (most frequently tuberculous, more rarely gangrenous or from an abscess), the first symptom is a sudden agonizing pain in the side, accompanied with dyspnoea amounting almost to suffocation. In rare instances, where strong old adhesions limit the pneumothorax, there may be only slight pain, without dyspnoea. The rush of a moderate quantity of air into the cavity causes the lung to collapse; but should the amount of air be excessive, it will render the symptoms of oppression most intense, for it will compress the lung and heart and obstruct the capillary circulation in the lung. Such must be the case, for there is no aspiration of blood from the large veins, and no aëration of blood in the lung. The patient often feels as if the chest were being torn away, and the expression of his countenance betrays distress and alarm. If the orifice be large and valvular, preventing the escape of the air, the air accumulates rapidly and completely forces the air out of the lungs, and death shortly follows, sometimes in a few hours. There is no rise of temperature or fever. On the contrary, the temperature very frequently falls one or two degrees below the normal in consequence of the sudden collapse, the pulse from exhaustion being very frequent and feeble, accompanied by cold sweats. The voice becomes exceedingly feeble and whispering. In many cases the patient does not sink at once from the shock of the perforation, but becomes less oppressed, although he suffers considerably, being unable to lie flat in his bed. Respiration is not only frequent (sometimes 60 per minute), but the dyspnoea is oppressive and distressing to witness. Fever follows invariably, and sometimes with great rapidity, caused by pleuritis. When this occurs, the patient again suffers from dyspnoea as the purulent fluid accumulates in the pleura and gradually dropsy comes on. These cause dyspnoea and cyanosis. The position of the patient, leaning forward, supporting his elbows on his knees, indicates his agony and difficulty in breathing; the pain appears to go through and produce local hyperæsthesia, and the patient dies from the empyema with hectic and oedema of the lungs. The pleurisy excited may be simply serous in its products, even when it is tuberculous in origin. Usually, however, it is purulent, and we must then expect to find the grave symptoms we have enumerated in speaking of empyema with hectic and septicæmia.