2. Introduction
Pleural effusion, sometimes referred to
as “water on the lungs,” is the build-up of
excess fluid between the layers of the
pleura outside the lungs.
The pleura are thin membranes that line
the lungs and the inside of the chest
cavity and act to lubricate and facilitate
breathing
The space between the visceral and
parietal pleura (i.e., the pleural space) is
a potential space normally containing
only about 2 to 5 mL of pleural fluid.
3. Types of
effusion
tend to form when there is increased
capillary hydrostatic pressure or
decreased osmotic pressure. Their
causes include: Congestive heart
failure, hypoalbuminemia, cirrhosis,
nephrotic syndrome
Transudates
tend to be the result of inflammation.
Their causes include: Malignancy,
empyema, hemothorax, chylothorax.
Exudates
Pleural effusions are divided
into transudates or exudates
depending on their protein
content and their lactate
dehydrogenase concentrations.
4. Causes
The most common causes of transudative (watery fluid)
pleural effusions include:
◦ Heart failure
◦ Pulmonary embolism
◦ Cirrhosis
◦ Post open heart surgery
Exudative (protein-rich fluid) pleural effusions are most
commonly caused by:
◦ Pneumonia
◦ Cancer
◦ Pulmonary embolism
◦ Kidney disease
◦ Inflammatory disease
Fluid accumulates in the pleural
space when the rate at which the
fluid forms exceeds the rate of by
which it is cleared. Pleural
effusions can also form when there
is transport of peritoneal fluid
from the abdominal cavity
5. Symptoms
Chest pain
Dry, nonproductive cough
Dyspnea (shortness of breath, or difficult, labored
breathing)
Orthopnea (the inability to breathe easily unless
the person is sitting up straight or standing erect)
6. Diagnose & Radiograph
Conventional radiography is usually the first step in the detection of a
pleural effusion. Other modalities used include computed tomography
(CT) and ultrasonography (US). CT and US are both sensitive in detecting
small amounts of fluid.
Chest radiographs in the lateral decubitus position (with the patient lying on
the side of the pleural effusion) are more sensitive and can detect as little as
50 mL of fluid.
Ultrasound is also used to diagnose
Pleural fluid analysis (an examination of the fluid removed from the pleura
space)
7. Management
Once a pleural effusion is diagnosed, its cause must be determined. Pleural fluid is drawn out of the pleural space in a
process called thoracentesis
After removal, the fluid may then be evaluated for:
1. Chemical composition including protein, lactate dehydrogenase(LDH), albumin, amylase, pH, and glucose
2. Gram stain and culture to identify possible bacterial infections
3. bcounts and differential white blood cell counts
4. Cytopathology to identify cancer cells, but may also identify some infective organisms
5. Other tests as suggested by the clinical situation – lipids, fungal culture, viral culture, tuberculosis cultures, lupus cell
prep, specific immunoglobulins
8. Treatment
Diuretics and other heart failure
medications are used to treat
pleural effusion caused by
congestive heart failure or other
medical causes
Video-assisted thoracoscopic
surgery (VATS)
A minimally-invasive approach that
is completed through 1 to 3 small
(approximately ½ -inch) incisions in
the chest. Also known as
thoracoscopic surgery, this
procedure is effective in managing
pleural effusions that are difficult
to drain or recur due to malignancy.
Sterile talc or an antibiotic may be
inserted at the time of surgery to
prevent the recurrence of fluid
build-up.
A thoracotomy is performed
through a 6- to 8-inch incision in
the chest and is recommended for
pleural effusions when infection is
present.
