What type of pleural effusion is associated with exudative criteria?

Exudative pleural effusion is characterized by the presence of high levels of protein and other substances in the pleural fluid, indicating that the effusion results from inflammation, infection, or malignancy. This type of effusion occurs when there is an increase in permeability of the pleural membranes, allowing larger molecules such as proteins or cells to leak into the pleural space.

Criteria for diagnosing exudative pleural effusions are based on specific laboratory findings from the pleural fluid, including elevated levels of protein, lactate dehydrogenase (LDH), and other inflammatory markers. Common causes include pneumonia, cancer, and pulmonary embolism, all of which prompt an inflammatory response leading to exudation of fluid.

In contrast, transudative pleural effusions arise from systemic processes that do not involve inflammation, such as congestive heart failure or cirrhosis, where the pleural fluid tends to have lower protein content. Malignant pleural effusions, while a specific type, still fit the criteria for exudative effusions due to the underlying malignancy causing enhanced vascular permeability. Chylothorax, although also associated with pleural effusions, is specifically related to the leakage of lymphatic fluid and is