PHYSICAL SIGNS.—These are well distinguished and marked, and lead easily to its diagnosis. Inspection shows the side to be immovable and the dilatation permanent; the spaces between the ribs are obliterated and the shoulder raised. There is no rhythmical expansion and contraction of the walls of the chest, the diaphragm is not elevated, and the liver and stomach are kept down. Air continues to enter the cavity, until the quantity is so great that its tension is equal to the atmospheric pressure. The contrast between this condition and that of the healthy side is very great. In the former the breathing is labored, with painful muscular contraction in the walls and whole side. Percussion over the chest gives a hyper-resonant sound, with a graver-pitched tympanitic resonance. There is but little sense of resistance to the finger, owing to the elasticity of the contained air. When fluid is secreted in the second stage we have absolute flatness at the base over a horizontal level, and tympanitic resonance above. The pitch of this last sound varies according to the tension of the gas contained in the chest and the correlative tension of the thoracic walls. If this tension be feeble, the pitch is higher; if it be extreme, the tone will be drum-like, muffled, acute, and the tympanitic character will be less easily perceptible. It may happen that the pitch will be so high that we may be misled and think there is flatness. It is not true flatness, but a clean and high-pitched sound, very different from the tympanitic sound usually found; it is sometimes remarkably metallic in character. With auscultatory percussion, using a solid pleximeter, we have the prolonged metallic resonance which Trousseau appropriately named the bruit d'airain.
The area of hyper-resonance and flatness on percussion is changed with the altered position of the patient. The fluid, obeying the law of gravitation, takes its hydrostatic level, and when the patient's chest is upright is horizontal. Hyper-resonance is often pronounced over the sternum, and sometimes infringes upon the healthy side. When the disease is on the left side it obliterates the normal dulness over the cardiac area.
Palpation.—Thoracic vibrations of the voice are not felt over the portion of the chest containing air, nor over that containing fluid. This absence of vocal fremitus is very characteristic. The hand detects that the heart has been displaced toward the sound side and that the abdominal viscera are pushed down.
Auscultation.—The auscultatory phenomena vary according to the cause of the pneumothorax and the size and direction of the orifice. In tubercular cases, where perforation has produced a large, free opening, as the air passes in and out of this large pleural cavity with firm walls (the lung having collapsed perhaps to one-third or less of its normal size), we have the physical conditions which give marked amphoric and metallic respiratory sounds, with absence of respiratory murmur. The amphoric breathing is of greatest intensity near the point of perforation, which ordinarily is at the mammary or upper scapular region, and is found in both inspiration and expiration. The cough and the whispered voice give the characteristic metallic quality. There is also metallic tinkling produced by droppings of fluid in the cavity, by the shaking of the body, or by vocalization. Even when the orifice in the lung is closed we may have amphoric echo, from sounds produced in the bronchi, and passing through a cavity filled with air. The intensity of these sounds varies in different cases. 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.
There is, in both kinds of orifices, the well-known splashing Hippocratian succussion sound on shaking the chest. The latter is pathognomonic of hydro-pneumothorax, and is sometimes heard when no other sign is present. The hands applied over the surface of the chest feel the fluctuations of the fluid striking against the interior walls. When pneumothorax follows purulent pleurisy we do not find immediately the pronounced symptoms nor the physical phenomena heretofore described as occurring when it is produced by rupture from the lung into the pleural cavity. The condition of the parts is very different. Pus is present in considerable quantity in the cavity, and the ulceration of the costal pleura and the soft walls of the chest allows the fluid to flow outward and air to enter the cavity. Or there may be necrosis of parietal pleura into a bronchus and consequent discharge of pus through the mouth. The lung is already disabled. The violent pain in the side and the dyspnoea are no longer found. Indeed, the exact time of the rupture and commencement of the discharge is frequently unknown to the patient himself. The symptoms of entrance of air into the pleural cavity may not occur for some time. The patient who has had empyema is made more uncomfortable; the discharge through the mouth is offensive, and its quantity and its character call attention to the chest, in which percussion shows the presence of air; auscultation gives amphoric breathing, and succussion demonstrates the presence of air and fluid in the pleural cavity. Very soon, however, the presence of air produces putridity of the secretion, with loss of appetite, fever, diarrhoea, and the other alarming symptoms of pyo-pneumothorax. In some instances the pleura discharges its contents and heals over. There is another variety of pneumothorax, which is ordinarily attended with only temporary inconvenience, and which may soon disappear, leaving the patient no worse than before the attack. This variety of pyo-pneumothorax may be produced by the sudden rupture of emphysematous vesicles, by coughing, or even without any unusual force in the expiratory effort, the alveoli having become extremely thin and brittle by degeneration of their walls. For the minute the pain is violent and the dyspnoea great, but it soon subsides, and in a few days the gas may be all absorbed, unless it is in large quantity. If the pleura is healthy and the lung not otherwise diseased, the rupture may not cause any inflammatory action, fever, or effusion. The rupture may heal over entirely, or if some inflammatory effusion is produced it will probably be rapidly absorbed. In exceptional cases pleurisy may be excited and the case become prolonged. While the air remains in the pleura we have the physical signs characteristic of pneumothorax—displaced heart, as shown by palpation and auscultation, tympanitic percussion resonance, amphoric breathing, and succussion.
DIAGNOSIS.—Ordinarily, there should be no difficulty in diagnosing pneumothorax, no matter how it is produced. We have simply to consider well the already-mentioned modes of the commencement of the disease, and give due value to the characteristic physical signs, especially displacement of the heart, hyper-resonance on percussion, absence of vocal fremitus, amphoric respiration, succussion, and decided shifting of flatness and resonance on change of position. When all these signs are present, each being in itself almost characteristic, there can be but little question. 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; and the heart is not displaced. Large superficial pulmonary cavities with firm but thin walls give us several of the physical signs of localized pneumothorax, such as amphoric respiration and metallic tinkling; but the succussion sound is never heard over them. The tympanitic percussion is rarely so pronounced in a cavity as in pneumothorax, and in the latter there is never the cracked-jar sound. In phthisical cavities of large size there probably would be depression instead of enlargement of the chest. The situation will ordinarily enable us to make the differential diagnosis, for localized pneumothorax is almost always low down in the thorax, and the pulmonary cavities but rarely below its middle third. The progress of the case and clinical history would clear up the diagnosis. If a circumscribed pneumothorax was present with phthisis, the diagnosis might be difficult. Powell calls attention to the similarity of some of the signs of acute congestion rapidly supervening at the base of a comparatively sound lung to those of pneumothorax. But in the former the resonance, although high-pitched, is not truly tympanitic, and the heart is not displaced. There is no other disease of the chest where we find in such close proximity the two extremes of percussion sounds—flatness from the secondary effused fluid, and the tympanitic resonance above. If delicate, slight percussion is used, the line of demarcation can be clearly defined; if, however, the force of the percussion stroke be even of moderate intensity, the flatness is mingled with the tympanitic quality, as it is in percussing from the left lobe of the liver to the stomach.
PROGNOSIS.—The prognosis is unfavorable and always uncertain. During the first few days after the rupture of the pleura it is especially bad, though it becomes less so as time goes by. There are cases where the perforation and its results appear to prolong life. "If the opposite lung be healthy, we may hope that arrest of the pulmonary disease may convert the case into one of chronic empyema" (Powell). But, unfortunately, the rupture often occurs when the patient is emaciated and dying of chronic lung ulceration. Cases of pyo-pneumothorax produced in advanced phthisis or by gangrene of the lung are almost invariably fatal. The most unpromising cases at first sometimes prove the least serious, and, again, those that appear at the commencement slight, contrary to expectation, die. 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. Laennec reported one case where the patient lived six years. Fuller250 reports another where the orifice was open at the end of eleven months, another nineteen months, and another twenty-seven months. We have mentioned Demarquay and Marotte's experiments of the innocuousness of air injected into the pleura. Air is harmless, as they have shown, in the pleura, unless sulphuretted hydrogen or sulphite of ammonia be developed. Fuller says the prognosis is very unfavorable when the effusion is large, with great displacement of the organs. Flint considers pneumothorax occurring as a complication of phthisis as almost hopeless. It is important to ascertain promptly the nature and direction of the opening, whether it be free or valvular.
250 Diseases of Chest.
TREATMENT.—This is in a great measure palliative. Hypodermics of morphia or opiates relieve the agony and lessen the shock caused by the perforation. Alcoholic and diffusible stimulants may sustain the heart in its struggle against the effects of dislocation and impaired circulation. Care must be taken not to depress the powers of reaction by too much morphia. Hot water in india-rubber bags applied to the chest gives great relief. Alcoholic stimulants must be given to prevent sinking from exhaustion. When the distension from air is excessive, paracentesis gives marked relief, the lives of patients having been prolonged for days by it. If the opening is valvular, to prevent the air from accumulating in excessive quantity Reybard's protected gold-beater's skin trocar may be used and kept in the chest. Otherwise fine aspirators may be employed, which would seem to be harmless, and the operation be repeated whenever necessary. Larger points and the trocar should never be used, as there is danger of making a permanent fistulous orifice, as well as of injuring some blood-vessels or the lung itself. After the excess of air has been removed by aspiration the affected side should be strapped to control the inspiratory movements on renewal of positive pressure. Anstie251 recommends drachm ss doses of ether every three or four hours. Fernet252 recommends inhalation of oxygen. If fluid should compress the chest, some of it must be removed by aspiration, but care must be exercised, for the presence of fluid is conservative in its effects. Its pressure stops up the orifice and promotes its healing. If it becomes fetid, pleurotomy, with detersive washes, ought to be resorted to. Food should be frequently administered, with quinine and cod-liver oil, and good hygienic surroundings prescribed.
251 Reynolds's System of Medicine, vol. iv.