Synonyms.—Sero-Pneumothorax; Pyo-Pneumothorax.

Definition.—A collection of air in the pleural cavity, and, since this is nearly always accompanied by serum or pus, the terms sero-pneumothorax and pyo-pneumothorax are used interchangeably.

Etiology.—This is a condition of adult life, being rarely found in children, and occurs in males more frequently than in females, the ratio being about two to one. The left chest is more frequently the seat of election.

From seventy to ninety per cent of all cases of pneumothorax are due to pulmonary tuberculosis. Thus a tubercular cavity may rupture into the pleural cavity, or a caseous mass, suppurating, may open into the same and allow the entrance of air. The same conditions may result from gangrene of the lungs, from abscesses, from broncho-pneumonia, or a bronchial fistula may be established through emphysema; hydatids or malignant condition of the lung or esophagus may also be responsible for this lesion. Rupture of air-cells, from a severe paroxysm of coughing, as in whooping-cough, is a possible cause.

The condition may arise from perforation of the diaphragm due to perforating ulcer of the stomach, or from cancer of the stomach or colon, and, in very rare cases, from abscesses of the liver.

Penetrating wounds, or the opening of subpleural abscesses in the pleural cavity, is the most direct means of letting air into the pleura.

Pathology.—In some cases, owing to the valve-like action of the tissues at the seat of perforation, the pleural cavity becomes so distended as to displace the heart and spleen, and, if in the right side, the liver, and crowd the atelectatic lung back against the spine. When the pleura is punctured in this condition, the air escapes with a slight whistling sound. Usually there is but little difficulty in finding the rupture, quite often being located in the posterio-lateral region of the lung between the third and sixth ribs.

The pleural surfaces are usually inflamed and covered with a fibrinous exudate of varying consistency. In nearly all cases there is present: more or less sero-fibrinous or purulent fluid. Where tuberculosis exists, the walls are softened, and one or more perforations may be found. There may be a communication with a bronchus. The air is peculiarly effusive.

Symptoms.—There is a wide range of symptoms in pneumothorax. They may be so slight as to escape notice, and the condition only determined during an autopsy, or they may be so severe as to almost terminate the life of the patient, and between these extremes every grade is found.

The onset is generally sudden, the patient not infrequently being alarmed by the sensation of something having given away, and at the same time experiences, with the first rush of air, an intense pain in the side, great difficulty in breathing, being attended by a quick, small, thready pulse, coldness of extremities, and a pallid, anxious, or cyanotic appearance.

The dyspnea varies according to the amount of air and fluid present, and, where the opening is valve-like in character and egress of air is difficult, the pleura may become greatly distended, compressing the lung of the affected side and causing rapid, shallow breathing, which causes extreme distress and a sense of suffocation. Where the fluid is purulent, there is usually some fever of a hectic character.

Physical Signs.—The character of the physical signs vary according to the amount of air present, and whether only air be present. Where both air and fluid are found, the physical signs are distinct from those where fluid is absent.

Inspection.—Inspection reveals the interspaces filled or bulging and the affected side immobile, while the mobility of the healthy side may be exaggerated. Where the communication with the pleura is free, permitting air to enter and escape, there will be little or no distention. The heartseat is seen to be displaced.

Palpation.—The impulse of the heart is feeble and displaced, while tactile fremitus is diminished above, and may be entirely absent below where effusion is present.

Percussion.—The tympanitic quality of the resonance on percussion will depend upon the quantity of air and the degree of tension with which it is confined. Thus, where there is a communication with a bronchus, the pitch is higher when the mouth is closed, and lower when it is open. This is known as the "Wintrich Sign," while the "cracked-pot" sound occurs where the air in the pleural cavity connects with the outside air. Where there is fluid in the pleura, a dull, flat sound is heard as far as the fluid extends. Where there is great distention, the percussion note is high pitched, and when there is great displacement of the heart, resonance may be heard in the cardiac region.

Auscultation.—The natural rhythmic respiratory murmur is very feeble or entirely absent. What breath sounds are heard are feeble and amphoric in character. The respiratory murmur on the well side is exaggerated. If the ear be placed near the spine, bronchial breathing may be heard. A peculiar metallic or tinkling sound is sometimes heard, and is supposed to be due to dropping of fluid from the upper surface into the effused fluid.

The coin test is said to be characteristic and pathognomonic, and is performed by placing a coin flat upon the chest and striking it with another coin while the ear of the auscultator is placed at the back of the chest. The sound thus elicited is a peculiar metallic ringing or bell-like sound, not heard in any other condition.

Hippocratic succussion is also characteristic, and consists of shaking the patient while the ear is applied to the chest, when a splashing sound is heard.

Diagnosis.—The diagnosis is usually not difficult owing to the characteristic physical signs. The bulging of the intercostal spaces; the more or less displacement of the apex beat; the tympanitic percussion noted in the upper part of the chest, with dull or flat sound over the base where the fluid is present; the absent or feeble respiratory murmur; the amphoric breathing; the metallic tinkling sound as the dripping of water; the coin test of Trousseau, and the Hippocratic succussion splash,—make the diagnosis comparatively easy.

Prognosis.—The prognosis depends largely upon the cause. Where it occurs in individuals with good family history, arid where the previous health has been good, favorable prognosis can usually be made; but where it occurs in the advanced stages of phthisis, a fatal termination may be looked for in a few weeks.

Treatment.—The treatment is largely palliative or surgical. Thus, where the pain is severe, we have to resort to a hypodermic of morphia, though codein by mouth is preferable where the pain is less acute. Where the tension is extreme, the chest may be punctured by an aspirating needle, and where pus is present it may be withdrawn as in empyemia. In pyemic conditions, anti-suppurative remedies would be indicated, and where dyspnea is marked, some relief may be obtained from cardiac stimulants and tonics.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.