Pneumothorax

“ Obstruction of a large bronchus would be followed by absence of health sounds and intense dyspnoea, but we should not have the other physical signs of pneumothorax. Extensive emphysema would produce some of the signs—exaggerated resonance on percussion and enlargement of the side. Emphysema, however, is bilateral, and the resonance over an emphysematous lung has not the same pronounced tympanitic quality as in pneumothorax. The enlargement in emphysema is more under the clavicle; the breathing not amphoric; the normal murmur, although enfeebled, is never completely annulled ”

“ The irritating effects of gas, unless it comes in small quantities through the ribs from wounds in the chest-walls, are very frequently followed in a short time by the production of a quantity of serosity or of pus. If air is introduced into the pleural cavity from perforation of the lung, there is also liquid matter from the lungs of such a character as at once to provoke inflammatory action. Such a condition is then denominated hydro-pneumothorax or pyo-pneumothorax. The latter was, in fact, recognized by Hippocrates by the sign of succussion, though not so designated. ”

“ Traumatic pneumothorax may take place in consequence of an injury to the thoracic walls, of an exterior injury, or of a penetrating wound. The parts may be so bruised that pleural necrosis gives rise to sloughs and resulting openings. Fracture of ribs may tear the lungs, and allow air to enter the connective tissue and produce local emphysema. Violent contusions, as in a case recently observed by the author, produce laceration of the lung without the rib or costal pleura being injured. ”

“ Pneumothorax is the only pathologic condition associated with signs similar to those of expiratory, valve-like bronchial obstruction by a foreign body.
3. Partial bronchial obstruction by an object such as a nail allows air to pass to and fro with some degree of retardation, and impairs the drainage of the subjacent lung. Limitation of expansion will be found on the invaded side. The area below the foreign body will give an impaired percussion note. Breath-sounds are diminished in the area of dullness, and vocal resonance and fremitus are impaired. Rales are of great diagnostic import ”

“ 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. ”

“ Abnormal conditions of the pleuræ are frequent causes of cardiac displacements. In pneumothorax there is collapse of the lung on the affected side, and the elastic traction of the sound lung draws over the mediastinum and heart. It is not that the heart is pushed over, as so often stated, but the tension of the other lung, being unopposed, pulls the mediastinum toward the sound side. Later, when, as usually happens, effusion takes place, the pressure assists in the displacement. ”

“ If the air enters the pleura and takes the place of the pus, the chest remains enlarged. Indeed, it sometimes increases in size to such an extent as to cause suffocation unless the pus and gas are withdrawn. The valve made by the false membrane allowing the air to enter the cavity, but not to escape from it, causes the fluid to accumulate rapidly, and we have pneumothorax to a very painful degree. The diaphragm is pushed down, and, if the disease is on the right side, the liver is forced down, and descends to a level with the umbilicus. ”

“ The two lungs must, therefore, be alternately affected as to their capacity according as the heart occupies space on either side of the thorax. In expiration, the heart, E, is more uncovered by the shelving edges of the lungs than in inspiration. In pneumothorax of either of the pleural sacs the air compresses the lung, pushes the heart from its normal position, and the space which the air occupies in the pleura yields a clear hollow sound on percussion, whilst, by the ear or stethoscope applied to a corresponding part of the thoracic walls, we discover the absence of the respiratory murmur. ”

“ 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." ”

“ Their chests are built for the endurance of the special efforts of great speed, and we have lost those physical characters; and I venture to say that, if acute pneumothorax were suddenly inflicted upon sixty-three healthy adult human beings, death would be the immediate result in the great majority of the experiments.”—Lawson Tait, F.R.C.S., Brit. ”

“ Much depends upon the condition of the other lung and the position of the perforation. If the other lung be healthy and the perforation low down, the chances of recovery are better. The progress is most favorable in the cases where the rupture occurs from emphysema. When from purulent pleurisy the discharge passes through a bronchus, the orifice may heal and in due time plastic material be thrown over it, and the air and fluid be left in the pleura. Cases are reported where the orifice remains open and pneumothorax lasts for a long time. ”

“ In no autopsy has the orifice made by the needle been found, nor has it ever been known to produce pneumothorax. The quantity of albuminous sputa is out of all proportion to the orifice made. In several cases of reported perforation these symptoms did not occur. After the lung has been a long time compressed by an effusion, and when, in consequence of the expulsion of the liquid, it retakes its normal proportions, there occurs a rush of serum which is expelled by the bronchi. ”

“ In bronchial fistula, unless the air is prevented from coming from the lung into the pleura by a valvular opening, we have frequently to resort to pleurotomy. If in empyema necessitatis the orifice partly closes or is not free enough, we must not hesitate to enlarge it or make a counter-opening to enable the matter to flow out. In tubercular pyo-pneumothorax, where the purulent fluid has been the primary lesion and has perforated the lung, the operation is not indicated. ”

“ If, as in pneumonia, air has been displaced by inflammatory product occupying the air space, or if fluid collects in the lower part of the chest, the percussion sound becomes dull. If, as in emphysema, or in pneumothorax, [Pg 19] there is an excess of air in the chest cavity, the percussion sound becomes abnormally loud and clear.
Auscultation consists in the examination of the lungs with the ear applied closely to the chest wall. As the air goes in and out of the lungs a certain soft sound is made which can be heard distinctly, especially upon inspiration. ”

“ Sometimes they are very loud; in other cases they are feeble and seem distant from the ear. The fine metallic tinkling may be heard at one moment and disappear at the next. These amphoric and metallic sounds, heard at different points, are characteristic of pneumothorax with free openings. When, however, the orifice from tubercular perforation is small, oblique, or valvular, the respiratory murmur is inaudible, except perhaps at the very apex of the lung, and we cannot perceive any adventitious auscultatory phenomena beyond a faint, distant, hollow sound. ”

“ In pneumonia or inflammation of the lung-substance the process is different. A portion of one or other lung, sometimes of both, becomes overfilled with blood, or congested, and though the air-tubes themselves are not the special seat of the congestion, yet the air-cells are pressed on by the surrounding swollen substance, and the entrance of air into them is impeded. If the mischief goes further the substance becomes solid and impervious to air, and lastly it becomes softened, its structure destroyed, and infiltrated with matter ”

“ Superficial Examination of Thorax.—Observe the position, color, and degree of distention of the lungs. It should be remembered that healthy lungs, as soon as the chest is opened, owing to their inherent elasticity, will collapse, and when this normal collapse is not seen it is generally due to a loss of elasticity as occurs in emphysema, to inflammatory diseases binding the lung to the chest wall, or to the alveoli being filled with solid or fluid substances or pent-up air. Most complete distention is seen when death is due to drowning or suffocation. ”

“ Though the lungs are closely applied to the costal sides at all times in the healthy state of these organs, still they slide freely within the thorax during the respiratory motions—forwards and backwards—over the serous pericardium, E, and upwards and downwards along the pleura costalis. The length of the adhesions which supervene upon pleuritis gives evidence of the extent of these motions. When the lung becomes in part solidified and impervious to the inspired air, the motions of the thoracic parietes opposite to the part are impeded. ”

“ One of the most remarkable phenomena is the rapidity with which the lung tissue clears up, and its freedom from alteration or from infiltration into the connective tissue as frequently takes place after broncho-pneumonia. When resolution does not take place, death may occur from extension of the disease and subsequent toxaemia, from circulatory failure, from the formation of one or more abscesses or more rarely from gangrene of the lung or from the complication mentioned below. Chronic interstitial pneumonia is infrequent, following on the acute variety. ”

“ In other cases of pneumonia we get a certain amount of serous effusion into the pleura; and sometimes, especially in children, the pneumonia is followed by the development of an empyema. Pleurisy with effusion is also frequently a complication of valvular heart disease and dilatation of the heart, and in such cases is often associated with the formation of superficial pulmonary infarcts. It is also seen in many other diseases of the lungs. For instance, in chronic pulmonary phthisis pleuritic adhesion's over various parts of the lungs are the rule ”

“ In old age the stages rapidly merge into each other, and suppuration of the [p. 313] lung may occur within thirty-six or forty-eight hours from the onset of the pneumonia, while it is not at all infrequent for complete red hepatization to occur within the first six or eight hours.
The changes in the pleura over a pneumonic lung are quite characteristic. An uneven, thin, downy-looking layer of plastic lymph is spread over the pleural surface, which presents a fine arborescent vascularity. At times this plastic layer may partially conceal the liver-brown color of the pneumonic lung. ”

“ The lungs are freely suspended by the windpipe, and are distended by the atmospheric pressure in opposition to their elasticity. Consequently, an opening in the walls of the thorax is liable to produce suffocation, by giving the air a more direct and easy route to the vacuum of the chest than through the trachea and lungs.
A delicate membrane called the pleura closely invests the lungs, and is then reflected to line the cavity of the thorax. By the secretion of a serous fluid, it prevents friction, which would otherwise result from the constant movement. ”

“ When death occurs it is usually directly due to heart failure; in some cases it is caused by asphyxia, owing to the great amount of exudation into the lung tissue, rendering its further function impossible.
Complications.—The pulmonary complications of infectious pneumonia are secondary inflammatory or necrotic changes in the lungs themselves. Suppuration at times takes place in the bronchi and may extend to the lung tissue. In this case mucous râles develop which are most distinctly heard over the trachea and on the sides of the chest directly behind the shoulders. ”

“ The degree of cardiac failure present is to be ascribed rather to nervous exhaustion than, as in many cases of croupous pneumonia, to the action of hyperpyrexia on the muscle of the heart. The extreme interference with respiration in catarrhal pneumonia is readily accounted for, not only by the extent of lung-tissue actually involved in the process, but by the associated bronchitis with swelling of the mucous membrane, by the accumulated bronchial secretions, and by the frequent complication with collapse. ”

“ If the patient is breathing from twenty-five to thirty-five times per minute, the respiration being confined to one lung as indicated by the lack of expansion in the other, and if he lies so as to take the strain off the lung that does not expand, it is almost sure that the patient has pneumonia. In case the lung is fixed rigidly by the muscles and the opposite lung forced to do all the work, then the patient has pleurisy. ”

“ It should always be remembered that the lung undergoes very various and opposite changes as the result of pressure on the bronchi, interrupting the entrance and egress of air from the lobules, and the physical signs of emphysema, infarction, congestion, or consolidation may exist in one or the other side. The ordinary methods of physical examination indicate the existence of pleural effusions, but large growths extending from the mediastinum or originating in the lung may so closely simulate such effusions that a positive diagnosis can be arrived at only by paracentesis. ”