Normally a very small amount of fluid in the pleural cavity are present in the pleural fluid is not detectable by conventional methods. When there are disruptions, excess pleural fluid may accumulate and cause pulmonary symptoms. In short, a pleural effusion occurs when fluid is higher than the rate of construction of liquids. After symptomatic pleural effusion is not clear, the determination of diagnostic needs.
figure via intensivecare
Signs and Symptoms
chest pain, chest tightness, shortness of breath and cough are common symptoms of pleural effusion. The pain may occur with little formation fluid that the symptom is associated with intense inflammation of the pleural surface. pressure in the chest does not generally occur in the pleura in a moderate (500-1500 mL) to large (> 1500 ml) category. Dyspnea is rarely small, unless a large pleural effusion is present, and often the patient complains of shortness of breath, pleural is the most a quarter of the mediastinum in the chest x-ray opposite. The cough is usually associated with associated atelectasis, which to some extent, pleural effusion accompanied by all. Classic physical conditions in the pleural effusion can occur during the startup of more than 500 ml and it reduces breathing sounds, boring drums, decreased tactile and vocal tremor, and sometimes pleural rub. In contrast, pneumonia and atelectasis, itch with isolated pleural effusion.
In the presence of pleural effusion is suspected by physical examination, confirmation of the chest radiograph is not necessary. Some of the pleural effusion, especially subpulmonic location (the lower lung, but most of the hemidiaphragm), lateral decubitus film is generally confirms the presence of liquid. pleural ultrasonography is useful to locate a small quantity or single compartmentalized pockets of liquid. Chest can be performed simultaneously using ultrasound guidance. The CT scan is very useful in distinguishing disease of the pleura and parenchyma and thickening of the pleura may show calcification of the pleura, or pleural based masses partitioned fluid collections.
Thoracic and Pleural Fluid Analysis
To determine the etiology of chest should usually be made. Fifty to 100 ml of fluid are usually removed and sent for analysis (see Table 14). Everybody should be used in outpouring, but if the patient has no obvious cause of clinical effusion is a fever, or pulmonary compromise, eliminating the liquid. The first step is to determine if the fluid is a transudate or exudate. transudative effusion occurs when systemic factors that influence the creation and absorption of pleural fluid are the changes (eg, low serum proteins and increased pulmonary venous pressure). exudative effusions occur when local factors that influence the creation and absorption change of fluid (such as infections and cancers). Lactate dehydrogenase (LDH), protein concentration or density of liquid able to distinguish between these two. Most agree that states must meet one or more of the following criteria, but do not meet transudates:
Pleural Fluid Serum Proteins /> 0.5 or Absolute Value & gt; 3 g / dl.
pleural fluid / serum LDH> 0.6 or absolute value> 0.45 upper limit of normal serum
Pleural fluid density> 1.018
When effusion is classified as transudative or exudative narrow etiological considerations. pleural fluid in additional studies that help establish a diagnosis is glucose, amylase, WBC with differential, testing and cytology and microbiology.
Transudate: Causes of transudative pleural effusion are listed in Table 15th
Congestive Heart Failure:
This is the most common cause of pleural effusion. Often effusions are bilateral (approximately 75% of the time), but can occur on both sides of the line is more frequent. The fluid is usually straw-colored, with low white blood cell count (<500 cells / mm 3) and the predominance of mononuclear cells. In cases of severe congestive heart failure, fluid may persist despite vigorous diuresis. liver cirrhosis, nephrotic syndrome, lung and liver: In disorders associated with low serum proteins and ascites, bilateral effusions are common. blood cells are low and dominated by lymphocytes. Glucose is normal (> 60 mg / dl). Hepatic hydrothorax occurs in about 5% of patients with cirrhosis and ascites. Effusion occurs (usually on the right side) because of the direct flow of peritoneal fluid through messages in the hemidiaphragm.
Causes of exudative pleural effusion are listed in Table 16 The most common causes of exudative pleural effusions are parapneumonic (associated pneumonia), malignancy, pulmonary embolism, trauma (including perforation esophagus and hemothorax), a systemic inflammatory disease (rheumatoid arthritis in particular), after cardiac injury (including surgery), tuberculosis, trapped lung atelectasis. Pleural fluid properties are listed in Table 17
Bacterial pneumonia is often associated with pleural effusion (as often as 50% of the time), and when they become complex and require drainage. Is a complex parapneumonic effusions empyema (crude oil found in the pleural cavity), these positive culture of pleural fluid or Gram, and those in which microbiology is negative but the patient continues to show signs of infection by fever, pleural pain, and leukocytosis. In the latter category of pleural fluid usually shows a high number of polymorphonuclear leukocytes with advantage, glucose <30 mg / dl, and high LDH (> 500 U / dl). Complicated parapneumonic effusions require drainage tube thoracoscopy. Pneumonia patients with a small amount of fluid in the pleura and is currently a clinical response to treatment with antibiotics (currently afebrile pleural pain is not a normal number of white blood cells), does not require the chest. However, the rapid accumulation of fluid in the pleura in a patient with pneumonia is an indication for an immediate chest.
Malignant tumor is the second most common cause of exudative pleural effusion of lung (36%), breast (25%) and lymphomas (10%) is the most common cause. Typical features include fluid in the pleural effusion mononuclear main (approximately 2500 cells / mm 3), with an average number of red blood cells 40,000 / mm 3, normal glucose (> 60mg/dl) and a positive cytology. At the time of diagnosis one third of patients with low pleural fluid glucose (<60mg/dl), which is associated with more advanced disease and poor prognosis. School effusion of pulmonary embolism: bleeding generally leaky, and associated with pleurisy, and dyspnea. Effusion may increase the size of the first 24-48 hours after initial anticoagulation. Unless there is significant compromise pulmonary effusion is still increasing, the effusion can be observed. There are reports of transudative effusion associated with pulmonary embolism, but atelectasis secondary to splinting of the pleura is a more likely cause. Tuberculous Effusion: Exudate Usually mainly lymphocyte is devoid of mesothelial cells and can occur without any apparent involvement of the flesh. Glucose may be low (<60 mg / dl) and the concentration of adenosine deaminase is generally high (> 70 IU / l). Historically, in the absence of host resistance, pleural fluid smears are rarely positive, but the pleural fluid cultures were positive in 25%. However, thoracoscopic pleural biopsy and culture positive for more than 80% of the time. Originally a tuberculin skin test (TST) may be negative, but after 6 to 8 weeks of observation time is usually converted into a positive. tuberculous pleurisy, although developed in the context of primary infection of the disease spontaneously, without treatment removes up to 65% of these patients, pulmonary tuberculosis or other diseases develop within 5 years. If all the tests, including the Mantoux test is negative, but a pleural tuberculosis is suspected, repeat the TST and should be done if the patient needs a period of six months of multidrug therapy positive.
Effusions secondary collagen vascular disease: effusion secondary to rheumatoid arthritis are mainly extracted from mononuclear cells, usually from a very low level of glucose (<10mg/dl), titers of rheumatoid factor (> 640) and Poor appearance (cholesterol or effusion pseudochylous). They are usually of moderate size and biased. In lupus erythematosus effusions are usually small, two-and neutrophils are extracted. Determination of ANA securities exceeding the serum diagnosis. severe inflammation of the pleura is common.
Atelectasis is a common cause of low to moderate exudate. Often seen after surgery or prolonged bed rest and inactivity. There is no unique diagnostic and exudations exudative, they are usually classified according to the criteria, have normal blood sugar levels and white blood cell count of 1000-2000 cells / mm 3 with predominance of mononuclear cells. Transudate may occur from atelectasis. As this is a diagnosis of exclusion of other causes of pleural effusion should be eliminated. rupture of the esophagus and pancreas to produce predominantly polymorphonuclear pleural effusion with high amylase activity and glucose levels normal or low (<30 mg / dl) values. Chylothorax occurs when the thoracic duct is disrupted and characterized by the presence of chylomicrons and triglyceride values> 110 mg / dl in the pleural fluid. Lymphoma, trauma, thoracic surgery and are the most common cause of chylothorax. Dressler's syndrome may occur as a complication of myocardial infarction or open heart surgery, the fluid in the pleura effusion exhibits a predominantly neutrophils without definite conclusions. The trapped lung (which can not fully develop secondary visceral pleural peel), and pleural effusion fluid fills the pleural cavity and the fluid properties depend on the etiology (eg, cancer and parapneumonic, trauma) .
The Diagnostic Thoracoscopy and Pleural Biopsy
Thoracoscopy is an excellent technique to determine the etiology of exudative pleural effusion undiagnosed. This procedure is better than the old techniques of closed pleural biopsy because of high diagnostic yield. rigid thoracoscope with a cold light source is used and the second entry point is required to provide access to the biopsy forceps in the pleural cavity. This technique is still the most useful in the diagnosis of malignant effusions (including disease), pulmonary tuberculosis and imprisoned.
When I ask
According to local medical practice, a reference to determine if the chest is needed and the breast may be most appropriate. Because some imaging techniques, including ultrasound and CT scan may be necessary for the coordination and implementation of chest tubes in the chest, refer to connect these efforts is shown. In patients with persistent and undiagnosed pleural effusion, pleural or terminally ill with pneumonia, the call is to facilitate early diagnosis and therapeutic measures are recommended. This includes evaluation of thoracoscopy, the thoracic drain and pleurodesis.
The cases most forensic about the disease of the pleura are usually associated with complications that arise in the following situations: 1) lack of proper monitoring (eg, complicated parapneumonic effusion fibrothorax reason), 2) the absence of a system where doctors do not receive valid data (eg., a positive culture of tuberculosis in eight weeks), 3) loss to identify life-threatening events such as pulmonary embolism. Always, always keep track of pleural fluid cultures and cytology.