Thoracentesis is a procedure to remove
fluid from the space between the lungs and the chest wall called the pleural
space. Results from a lab are usually available in 1 to 2 working days. If the
fluid is being tested for an infection, such as
tuberculosis, results may not be available for several
A small amount of clear,
colorless, or pale yellow pleural fluid, usually less than
20 mL (0.7 fl oz), is normally
present. No infection, inflammation, or cancer is found.
A large amount of pleural
fluid is present.
Fluid may be labeled as either
a transudate or an exudate. The difference between these two types of fluid has
to do with the amount of protein and other substances found in the
Heart failure or
enlargement of the right side of the heart (cor pulmonale).
biopsy may be done at the same time as a thoracentesis
to collect a sample of tissue from the inner lining of the chest
Thoracentesis may be done before another procedure called
pleurodesis. During this procedure, a chemical or medicine (talc or
doxycycline) is put into the pleural space, which triggers an inflammatory
reaction over the surface of the lung and inside the pleural space. This in
turn causes the layer of pleura attached to the lung to stick to the layer of
pleura on the inside of the chest wall. This takes away the space between the
pleura and prevents or reduces the collection of more pleural fluid.
Pleurodesis may be done when fluid collects in the chest more than one
time and the reason for the fluid buildup cannot be corrected.