Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
A pleural effusion is a collection of fluid in the space between the two
linings (pleura) of the lung.
When we breathe, it is like a bellows. We inhale air into our lungs and the ribs move out and the diaphragm moves down. For the lung to expand, its lining has to slide along with the chest wall
movement. For this to happen, both the lungs and the ribs are covered with a
slippery lining called the pleura. A small amount of fluid acts as a lubricant
for these two surfaces to slide easily against each other.
Too much fluid impairs the ability of the lung to expand and move.
What causes pleural effusion?
A pleural effusion is not normal. It is not a disease but rather a
complication of an underlying illness. Extra fluid (effusion) can occur for a
variety of reasons. Common classification systems divide pleural effusions based
on the chemistry composition of the fluid and what causes the effusion to be
formed. Two classifications are 1) transudate pleural effusions; and 2) exudate
pleural effusions. Sometimes the pleural effusion can have characteristics of
both a transudate and an exudate.
1. Transudate pleural effusions are formed when fluid leaks from blood
vessels into the pleural space. Chemically, transudate pleural effusions contain
less protein and LDH (lactate dehydrogenase) than exudate pleural effusions. If
both the pleural fluid–to–serum total protein ratio is less than or equal to
0.50 and the pleural fluid–to–serum LDH ratios are less than or equal to 0.67,
the fluid is usually considered to be a transudate while exudates ratios are
above 0.50 and above 0.67.
The most common symptom of pleural effusion is shortness of breath or
difficulty breathing. As the
effusion grows larger the more difficult it is for the person to breathe.
Chest pain is also a symptom of pleural effusion and occurs because the pleural lining of the lung is irritated. The
pain is usually described as a sharp pain, worsening with
a deep breath.
As the pleural effusion increases in size, the pain also may increase.
Other associated symptoms of pleural effusion are due to the underlying
disease. For example, a person with congestive heart failure may have signs and
symptoms of feet swelling and shortness of breath while laying flat. Someone
with pneumonia may have a fever, chills, and a cough that produces colored
sputum and pleural pain.
There are many causes of chest pain, and while many are not serious, it may be difficult to distinguish among heart attack, pulmonary embolus or aortic dissection, and another diagnosis that is not life-threateni"...