Synonyms:—Purulent pleurisy; pleuritis with purulent effusion.

Definition:—A condition of sub-acute or chronic pleurisy, in which, from the characteristic micro-organisms present, pus develops in the pleural cavity instead of or in conjunction with the serous or sero-fibrinous effusion.

Etiology:—Various micro-organisms are found present in the purulent fluid of empyema. The condition develops where the system has become reduced and devitalized, or where there have been pronounced blood changes. It is seldom that the condition follows an uncomplicated case of dry pleurisy, but as a sequel of the sub-acute form of pleurisy it occurs in a large per cent of cases which have not had previous good care. It may occur also where aspiration—thoracentesis—has not been aseptically performed. It occurs secondarily to infectious diseases, to other forms of pleuritis, and is especially liable to occur after pyemia or septicemia. In cases of protracted inflammation of the lungs abscesses form, which may open into the pleural sac, or tubercular cavities may perforate the structure of the pleura and discharge their contents, from which pus rapidly develops. Penetrating wounds of the chest walls or external injuries which result in inflammation of the pleura, and extensive burns, may cause this condition.

Symptomatology:—The development of pus in the plural sac is ushered in with symptoms similar to those present from the formation and absorption of pus in any locality. There is a sudden rise of temperature, with a sharp chill, or with persistent chilliness. The pain in the affected side which, in a case of previous pleurisy, may have almost entirely abated, increases rapidly, until it becomes very severe. There is rapidly increasing difficulty in breathing, often with incessant cough, which greatly exaggerates the pain. The fever quickly assumes a hectic form, with night sweats and rapidly increasing prostration. Emaciation follows and paleness to extreme pallor develops.

The physical signs are those of serous effusion. It must be borne in mind that in some few cases the pus forms slowly and may be walled off or separated from the surrounding tissues—ensacculated as it were—under which circumstances the constitutional symptoms may be delayed or may develop slowly. As the emaciation progresses the distention of the intercostal spaces appears much more conspicuous than is apparent in ordinary cases of serous effusion. If gangrene be present with the pyemic condition, or if the empyema is greatly prolonged, symptoms of destruction of the blood corpuscles are apparent, closely resembling those of typhoid fever, with dry mucous membranes, dark red in color, a long, thin, pointed tongue, coated with a dark brown or black coat and sordes.

Diagnosis:—The character of the symptoms named in almost every case, preceded by some other severe disease, render the diagnosis not difficult. The use of the exploratory puncture with a hypodermic needle, described under serous effusion, will confirm the diagnosis.

Treatment:—The treatment of the attendant conditions will be conducted in the line of rational adjustment of specific measures as suggested in the other forms of pleuritis. The free drainage of the pleural sac and its subsequent irrigation are demanded. In children much caution should be used in irrigation and in the character of the fluid used. The warm physiological salt solution is the safest of irrigating fluids. A ten per cent solution of the peroxide of hydrogen, prepared when used, has been very successful with the author. Carbolic acid is useful, but there is much danger of its being used too strong. A 1-to-3000 to a 1-to-5000 solution is as strong as should be used with children. The author has used a solution of the permanganate of potassium in extreme cases, followed by warm sterilized water.

In cases greatly prostrated the evacuation of the chest should be conducted with much care. Stimulants should be used hypodermically before the operation, and hot water bottles and persistent stimulation should follow the operation. The most active measures should be conducted for the restoration of the patient, as the condition is even more severe than is often present after surgical operations, or with profound prostration from other exhausting disease. From the first evidence of infection echinacea or other carefully selected remedy calculated to antagonize the formation of pus and its influence upon the system, should be persistently used.

The Eclectic Practice of Medicine with especial reference to The Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.