Since my dad died of complications and hospital acquired infections, after a triple bypass, I am well aware of the things that can occur, following surgery. He developed very serious pneumonia, that he could never recover from, in spite of the continual use of antibiotics.
Pleural effusion occurs when excess fluid accumulates in the pleural cavity. While there is normally some fluid present in the pleural cavity, a healthy person will have less than 15 ml of fluid in each space. Lymphatics will usually absorb this fluid, but when they cannot, because of an overabundance, a pleural effusion occurs. The excess fluid can be thin or very thick. This is quite common after cardiac surgery, and occurs in up to 90% of bypass patients. Pleural effusion may occur during the first 30 days after surgery, or it can also occur later.
The pleural spaces are small spaces between the lungs and the rib cage, and they are covered by a thin membrane called the pleura. When pleural effusion occurs, the lungs cannot fully expand.
Diagnosis can be made through the use of chest x-rays and CT scans, as well as analyzing apparent symptoms, such as decreased breath sounds, and movement of the chest, on the affected side. In some cases, there is shortness of breath, chest pain, and occasionally fever, though not always. Determination of the cause can be obtained by a procedure in which a needle is placed through the chest wall, into the pleural space, allowing fluid to be withdrawn. This is called thoracentesis.
There are 2 types of pleural effusion, (transudative and exudative), and depending on the type, the causes can include bacterial pneumonia (which my father had), cancers such as lung, breast, and lymphoma, viral infections, pulmonary embolism, cirrhosis, tuberculosis, lupus, bleeding, trauma to the chest, rupture of the esophagus, asbestos exposure, abdominal abscesses, and rheumatoid arthritis, as well as other causes.
One of the other major causes is through medical procedures, such as bypass surgery. My dad frequently had to have copious amounts of fluid drained from his lungs, and pleural cavities, after triple bypass surgery. But it just kept building up again. Of course, he also had extreme pneumonia. Pleural effusion occurs in about 30-40% of people with bacterial pneumonia, and the complication factor is much higher, than in those without pneumonia.
Treatment can involve removing excess fluid with chest tubes or suction. Therapeutic aspiration is sometimes effective, but a drain may also, at times, be required. This is known as an intercostal drain. If the effusions continue to occur, then a different procedure may be required chemically or surgically, in which the pleural surfaces are bound together to stop the accumulation of fluid. This is called chemical or surgical pleurodesis.
Sometimes after bypass surgery there can be a small amount of blood in the pleural cavity. This can cause a lung to collapse. However, in most cases, the pleural effusions are small, and will disappear. Often, even large pleural effusions, will resolve spontaneously over time. Sadly, most pleural effusions cannot be prevented.
Sources:http://en.wikipedia.org/wiki/Pleural_effusion
http://www.bio-medicine.org/medicine-news/Bypass-Surgery-26-Pleural-Effusion-1719-1/
http://sci.tech-archive.net/Archive/sci.med.cardiology/2008-04/msg00392.html
http://www.med.umich.edu/1libr/aha/aha_pleffu_crs.htm
