Pleural Effusion

When excess fluid builds up in the pleural space, this is called a pleural effusion.

The buildup of fluid usually forces the two layers of the pleura apart so they don't rub against each other when you breathe. This can relieve pleuritic pain (pain when taking a breath) caused by pleurisy (inflammation of the pleura).

However, a large amount of extra fluid can push the pleura against your lung until the lung, or a part of it, collapses. This can make it hard for you to breathe.

In some cases of pleural effusion, the extra fluid gets infected and turns into an abscess. This is called an empyema.

You can develop a pleural effusion if you don't have pleurisy. For example, pneumonia, heart failure, cancer, or a pulmonary embolism can lead to a pleural effusion.

What Causes Pleural Effusion?

The most common cause of pleural effusion, or fluid in the pleural space, is congestive heart failure. Lung cancer, pneumonia, tuberculosis, and other lung infections also can cause swelling of the pleura and lead to a pleural effusion. Asbestosis, sarcoidosis, and reactions to some medicines also can lead to pleural swelling and pleural effusion.

What Are the Signs and Symptoms of Pleural Effusion?

Pleural effusion often has no symptoms.

How Is Pleural Effusion Diagnosed?

Your doctor will find out if you have a pleural disorder by taking a detailed medical history and doing a physical exam and several tests. The purpose is to:

• Rule out other causes of your symptoms
• Find the cause of the pleurisy or other pleural disorder so it can be treated

Medical History

Your doctor will ask you for a detailed medical history. He or she is likely to ask you to describe the pain, especially:

• What it feels like
• Where it's located and whether you can feel it in your arms, jaw, or shoulder
• When it started and how long you've had it
• What makes it better or worse
• Whether it goes away and then comes back

Your doctor will probably also want to know about any other symptoms that you may have, like shortness of breath, cough, or palpitations (a feeling that your heart has skipped a beat or is beating too hard).

Other things your doctor is likely to ask about include whether you've ever:

• Had heart disease
• Smoked
• Traveled to places where you may have been exposed to tuberculosis
• Had a job that exposed you to asbestos
• Taken nitrofurantoin or amiodarone or a medicine that can cause a condition that's similar to systemic lupus erythematosus (an autoimmune disorder)

Physical Exam

Your doctor will listen to your breathing with a stethoscope to find out whether your lungs are making any strange sounds.

When you have pleurisy, the inflamed layers of the pleura make a rough, scratchy sound as they rub against each other when you breathe. Doctors call this a pleural friction rub. If your doctor hears the friction rub, he or she will know that you have pleurisy.

If you have a pleural effusion, fluid has built up in the pleural space and pushed the two layers of the pleura apart so that they don't produce a friction rub. But if you have a lot of fluid, your doctor may hear a dull sound when he or she taps on your chest. Or the doctor may have trouble hearing any breathing sounds.

Reduced breathing sounds also can be a sign of pneumothorax.

Diagnostic Tests

Depending on the results of your physical exam, your doctor may recommend other diagnostic tests.

Chest X Ray

A chest x ray takes a picture of your heart and lungs. It may show air or fluid in the pleural space. It also may show what's causing the condition—for example, pneumonia, a fractured rib, or a lung tumour.

Sometimes an x ray is taken while you lie on the side where the pain is. This may show fluid that didn't appear on the standard x ray taken while you were standing.

Computerized Tomography (CT) Scan

This test provides a computer-generated picture of your lungs that can show pockets of fluid. It also may show signs of pneumonia, a lung abscess, or a tumour.

Ultrasound

This test uses sound waves to create pictures of your lungs. It may show where fluid is located in your chest. It also can show some tumours.

Magnetic Resonance (MR) Scan

This test also is called nuclear magnetic resonance (NMR) scanning or magnetic resonance imaging (MRI). It uses powerful magnets and radio waves to show pleural effusions and tumours.

Blood Tests

Blood tests can show whether you have a bacterial or viral infection, pneumonia, rheumatic fever, a pulmonary embolism, or lupus.

Arterial Blood Gas Tests

In this test, a small amount of blood is taken from an artery in your wrist. It's then checked for oxygen and carbon dioxide levels. This test shows how well your lungs are taking in oxygen.

Thoracentesis

Once your doctor knows whether fluid has built up in the pleural space and where it is, he or she can remove a sample for testing. This test is called thoracentesis. The doctor inserts a small needle or a thin, hollow, plastic tube through the ribs in the back of your chest into your chest wall and draws fluid out of your chest.

Thoracentesis usually doesn't take long. Most of the time, it can be done in your doctor's office or at your hospital bed. Many doctors use ultrasound to guide the needle to the fluid that's trapped in small pockets around your lungs.

Thoracentesis usually doesn't cause serious complications, but your doctor may do a chest x ray after the procedure to be sure. Most of the complications are minor and will get better on their own, or they're easily treated.

Possible complications of thoracentesis include:

• Pneumothorax, or buildup of air in the pleural space, with a collapsed or partially collapsed lung. Sometimes air comes in through the needle or the needle makes a hole in your lung. Usually, a hole will seal itself. But sometimes air can build up around the lung and make it collapse. The doctor may need to use a chest tube to remove the air and let the lung expand again.
• Pain.
• Bleeding and bruising where the needle went in. In rare cases, bleeding may occur in or around the lung. The doctor may need to use a chest tube to drain the blood. In some cases, surgery may be needed.
• Infection where the needle went in.
• Liver or spleen injury. This is very rare.

Fluid Analysis

Doctors look at the fluid removed by thoracentesis under a microscope. They look at the chemicals in it and its color, texture, and clearness for signs of infection, cancer, or other conditions that may be causing the buildup of fluid or blood in the pleural space.

Biopsy

If your doctor thinks that tuberculosis or cancer may have caused the fluid buildup, he or she may want to look at a small piece of the pleura under a microscope.

To take a tissue sample, the doctor may:

• Insert a needle through the skin on your chest to remove a small sample of the outer layer of the pleura.
• Insert a small tube with a light on the end (endoscope) into tiny cuts in your chest wall so that the doctor can see the pleura. He or she can then snip out small pieces of tissue. This procedure must be done in the hospital under general anesthesia.
• Snip out a sample of the pleura through a small cut in your chest wall. This is called an open pleural biopsy. It's usually done if the sample from the needle biopsy is too small for an accurate diagnosis. This procedure must be done in the hospital under general anesthesia.

How Are Disorders of the Pleura Treated?

Goals of Treatment

The goals of treatment are to:

• Remove the fluid, air, or blood from the pleural space
• Relieve symptoms
• Treat the underlying condition

Remove Fluid, Air, or Blood From the Pleural Space

If large amounts of fluid, air, or blood aren't removed from the pleural space, they may put pressure on your lung and cause it to collapse.

The procedures used to drain fluid, air, or blood from the pleural space are similar.

• During thoracentesis, the doctor inserts a needle or a thin, hollow, plastic tube through the ribs in the back of your chest into your chest wall. A syringe is attached to draw fluid out of your chest. This procedure can remove more than 6 cups of fluid at a time.
• When larger amounts of fluid must be removed, a chest tube may be inserted through your chest wall. The doctor injects a local painkiller into the area of your chest wall outside where the fluid is. He or she will then insert a plastic tube into your chest between two ribs. The tube is connected to a box that suctions the fluid out. A chest x ray is taken to check the tube's position.
• A chest tube also is used to drain blood and air from the pleural space. This can take several days. The tube is left in place, and you usually stay in the hospital during this time.
• Sometimes the fluid contains pus that is very thick or blood clots. Or it may have formed a hard skin or peel. This makes it harder to drain the fluid. To help break up the pus or blood clots, the doctor may use the chest tube to put certain medicines into the pleural space. These medicines are called fibrinolytics. If the pus or blood clots still don't drain out, you may need surgery.

Relieve Symptoms

For relief of pleurisy symptoms, your doctor may recommend:

• Paracetamol or anti-inflammatory agents, such as ibuprofen, to control pain.
• Codeine-based cough syrups to control a cough.
• Lying on the painful side. This may make you more comfortable.
• Breathing deeply and coughing to clear mucus as the pain eases. Otherwise, you may develop pneumonia.
• Getting plenty of rest.

Treating the Underlying Condition

Looking at the fluid under a microscope can often tell the doctor what's causing the fluid buildup. Then treatment of the underlying condition can begin.

If the fluid is infected, treatment involves antibiotics and draining the fluid. If the infection is tuberculosis or from a fungus, treatment involves long-term use of antibiotics or antifungal medicines.

If the fluid is caused by tumours of the pleura, it may build up again quickly after it's drained. Sometimes antitumour medicines will prevent further fluid buildup. If they don't, the doctor may seal the pleural space. This is called pleurodesis.

In pleurodesis, the doctor drains all the fluid out of the chest through a chest tube. Then he or she pushes a substance through the chest tube into the pleural space. This substance irritates the surface of the pleura. This causes the two layers of the pleura to squeeze shut so there is no room for more fluid to build up.

Chemotherapy or radiation treatment also may be used to reduce the size of the tumours.

If congestive heart failure is causing the fluid build-up, treatment usually includes diuretics and other medicines.

Key Points

• Pleurisy is inflammation (swelling) of the pleura. The pleura is a large, thin sheet of tissue (membrane) that wraps around the outside of your lungs and lines the inside of your chest cavity.
• Pleurisy occurs when the two layers of the pleura become red and inflamed. Then they rub against each other every time your lungs expand to breathe air in. A pleural effusion is a buildup of fluid in the pleural space.
• The most common cause of pleural effusion is congestive heart failure.
• Pleural effusion often has no symptoms.
• Your doctor will find out if you have a pleural disorder by taking a detailed medical history and doing a physical exam and several tests.
• Treatment for pleurisy is designed to remove the fluid, air, or blood from the pleural space, relieve symptoms, and treat the underlying condition.
• If the condition that caused pleurisy isn't too serious and is diagnosed and treated early, you can expect a full recovery.