The American Thoracic Society divides pleural cavity infection into three phases based on the natural progression of septic chest: (i) exudative phase; (ii) fibrinous and purulent phase; and (iii) mechanized phase. These substages cannot be clearly distinguished, but the difference between the stages can be seen based on serial samples. stage I or the exudative stage, the pleural fluid is a thin exudate with a white blood cell count <1000/mm3, LDH below 500 IU, pH >7.30, and sugar >60 mg/dl. This stage is also known as simple peripulmonary effusion and is usually treated with antimicrobial agents. stage II or the fibrinous and purulent stage, characterized by infectious This stage is also known as complicated peri-pulmonary effusion, in which the pleural fluid becomes cloudy and bacteria and cellular debris may be detected, with sugar levels usually <40 mg/dl, LDH >1000 IU, WBC >5000/mm3, and pH <7.10. This stage is also known as complicated peri-pulmonary effusion, in which fibrin settles on the pleural surface and, as the disease progresses, fibrinopurulent septa separate the pleural cavity into two or more interstitial spaces, which means that a refractory peri-pulmonary effusion develops. As the effusion thickens, gel-like masses adhere to the pleural surface, limiting lung expansion, and without pleural cavity drainage, the bacterial content increases and the pleural fluid becomes purulent and becomes a true septic chest. In this stage, it is very difficult to remove the pleural fluid and stop the spread of infection by non-surgical means. Pleural fluid with marginal sugar, pH and LDH does not necessarily require immediate drainage, but after 12 to 24 hours of treatment, repeat pleurodesis is indicated for pleural cavity drainage if pathogenic bacteria are found or if biochemical parameters show deterioration. stage III, chronic or mechanized, fibroblasts implant in the pleural cavity, producing inelastic fibrous membranes (or fibrous plates), which encircle the lungs and affect lung function . Treatment with chest tube drainage alone is not sufficient in this stage and additional treatment is required to eliminate the pleural cavity infection. Wang Cheng, Department of Thoracic Surgery, Shandong Provincial Chest Hospital
Tuberculous abscess chest may have cheese like material to calcification. Due to the accumulation of pus in the pleural cavity, the lung is restricted by the mechanized fibrous scar wrapping, which affects the respiratory movement of the lung. The diaphragm is also immobilized by the thickened fibrous plates. The mediastinum is displaced to the affected side by the scar pull, the chest wall is invaginated, the ribs are clustered, the rib space is narrowed, and the spine is scoliosis. Due to long-term chronic hypoxia, pestle-like fingers (toes) may occur. In patients with chronic abscess chest, due to long-term infection poisoning, amyloidosis may occur in liver, kidney, spleen and other organs, and clinically liver and spleen enlargement and dysfunction may occur. Some chronic abscess chests, directly penetrate the pleura, through the intercostal space, forming dumbbell-shaped abscesses, called external penetrating abscess chest.