The process of draining fluid from the lungs is called thoracentesis. The thoracentesis procedure takes 10 to 15 minutes, from administration of local anesthetic in the chest wall to removal of the lung fluid, says WebMD.
The thoracentesis procedure is performed at a doctor's office or hospital. Before the procedure, the doctor confirms the presence of the fluid via a chest X-ray, an ultrasound or a chest-computed tomography. During the thoracentesis procedure, the doctor inserts a needle or tube into the pleural space, which is the space between the lungs and the chest wall, and draws out the excess fluid around the lungs and into a bag, as stated by the National Heart, Lung and Blood Institute.
Thoracentesis is performed for diagnostic and therapeutic reasons. When fluid accumulates in the pleural space, it often indicates underlying abnormalities. The diagnostic use of thoracentesis involves removing the fluid to confirm or rule out infections and diseases such as cancer, systemic lupus, pulmonary embolism or congestive heart failure. The therapeutic use of thoracentesis is to relieve discomfort from shortness of breath, according to Johns Hopkins Medicine.
Doctors may also perform a pleural biopsy at the same time as the thoracentesis procedure to retrieve a piece of tissue from the inner chest lining for further diagnostic testing, according to Healthline.