<unk>  Transudative The most common causes of transudative<unk>  in the United States are heart failure and cirrhosis. Nephrotic syndrome, leading to the loss of large amounts of albumin in urine and resultant low albumin levels in the blood and reduced colloid osmotic pressure, is another less common cause of<unk> . Pulmonary emboli were once thought to cause transudative<unk> s, but have been recently shown to be exudative. The mechanism for the exudative<unk>  in pulmonary thromboembolism is probably related to increased<unk> rmeability of the capillaries in the lung, which results from the release of cytokines or inflammatory mediators (e.g. vascular endothelial growth factor) from the platelet-rich blood clots. The excessive interstitial lung fluid traverses the visceral pleura and accumulates in the pleural space. Conditions associated with transudative<unk> s include: * Congestive heart failure * Liver cirrhosis * Severe hypoalbuminemia * Nephrotic syndrome * Acute atelectasis * Myxedema *<unk> ritoneal dialysis * Meigs's syndrome * Obstructive uropathy * End-stage kidney disease Exudative<unk>  Anteroposterior Chest X-ray of a<unk> . The A arrow shows fluid layering in the right pleural cavity. The B arrow shows the normal width of the lung in the cavity When a<unk>  has been determined to be exudative, additional evaluation is needed to determine its cause, and amylase, glucose, pH and cell counts should be measured. * Red blood cell counts are elevated in cases of bloody<unk> s (for example after heart surgery or hemothorax from incomplete evacuation of blood). * Amylase levels are elevated in cases of esophageal rupture, pancreatic<unk> , or cancer. * Glucose is decreased with cancer, bacterial infections, or rheumatoid pleuritis. * pH is low in empyema (<7.2) and maybe low in cancer. * If cancer is suspected, the pleural fluid is sent for cytology. If cytology is negative, and cancer is still suspected, either a thoracoscopy, or needle biopsy of the pleura may be<unk> rformed. * Gram staining and culture should also be done. * If tuberculosis is possible, examination for Mycobacterium tuberculosis (either a Ziehl–Neelsen or Kinyoun stain, and mycobacterial cultures) should be done. A polymerase chain reaction for tuberculous DNA may be done, or adenosine deaminase or interferon gamma levels may also be checked. The most common causes of exudative<unk> s are bacterial pneumonia, cancer (with lung cancer, breast cancer, and lymphoma causing approximately 75% of all malignant<unk> s), viral infection, and pulmonary embolism. Another common cause is after heart surgery when incompletely drained blood can lead to an inflammatory response that causes exudative pleural fluid. Conditions associated with exudative<unk> s: * Parapneumonic<unk>  due to pneumonia * Malignancy (either lung cancer or metastases to the pleura from elsewhere) * Infection (empyema due to bacterial pneumonia) * Trauma * Pulmonary infarction * Pulmonary embolism * Autoimmune disorders * Pancreatitis * Ruptured esophagus (Boerhaave's syndrome) * Rheumatoid pleurisy * Drug-induced lupus Other/ungrouped Other causes of<unk>  include tuberculosis (though stains of pleural fluid are only rarely positive for acid-fast bacilli, this is the most common cause of<unk> s in some developing countries), autoimmune disease such as systemic lupus erythematosus, bleeding (often due to chest trauma), chylothorax (most commonly caused by trauma), and accidental infusion of fluids. Less common causes include esophageal rupture or pancreatic disease, intra-abdominal abscesses, rheumatoid arthritis, asbestos<unk> , mesothelioma, Meigs's syndrome (ascites and<unk>  due to a benign ovarian tumor), and ovarian hyperstimulation syndrome.<unk> s may also occur through medical or surgical interventions, including the use of medications (pleural fluid is usually eosinophilic), coronary artery bypass surgery, abdominal surgery, endoscopic variceal sclerotherapy, radiation therapy, liver or lung transplantation, insertion of ventricular shunt as a treatment method of hydrocephalus, and intra- or extravascular insertion of central lines.
Pleural effusion
Pleural empyema
Pleurisy
Parapneumonic effusion
Hydrothorax
Pneumothorax
Malignant pleural effusion
Hemothorax