Patient Information

Pleural Aspiration and Drainage


Information for patients who are having a pleural aspiration or drainage.

Lung diagram

A pleural effusion is when fluid develops between the two layers of tissue that surround the lung known as the pleura. If the effusion is large, it can put pressure on the lung leading to difficulty in breathing, cough and sometimes pain.

Pleural effusions can occur around one lung (unilateral) or both lungs (bilateral).

What causes pleural effusions?

There are many causes of pleural effusions, but the causes tend to be different if the effusion is unilateral or bilateral. Some common causes are:

  • Unilateral pleural effusion: often caused by a problem within the lung itself e.g. infection, inflammation, or cancer.
  • Bilateral pleural effusion: often caused when the heart, liver or kidneys are not working normally. Bilateral effusions often improve with treatment of the underlying cause.

What does pleural aspiration and drainage involve?

Pleural aspiration and drainage are diagnostic procedures. They are similar but drainage involves an additional step to allow more fluid to be removed. You will be informed whether you are having an aspiration or drainage before the procedure.

Pleural Aspiration

Local anaesthetic will be used to numb your skin. A small needle is then passed into your chest to remove a sample of fluid. The procedure often takes about 30 minutes.

Pleural Drainage

Local anaesthetic will be used to numb your skin. A small plastic chest tube is then passed into your chest and connected to a drainage bag to allow a large amount of fluid to be removed. The chest tube is then removed and a dressing is applied. Pleural drainage usually takes about 45 minutes.

Depending upon the cause of the effusion you may need other treatments to stop the effusion returning. This can also include further pleural drainage.

What are the advantages?

A pleural aspiration allows a small amount of fluid (20 to 100mls) to be sent for tests to help work out what caused the effusion. This will also help us to understand if the fluid is likely to return.

Pleural drainage allows fluid to be sent for tests and also allows fluid (up to 1500mls) to be removed to help improve your breathing.

What are the risks?

Pleural aspiration and drainage are generally considered very safe procedures. However, as with all medical procedures, there are risks. These include:

Bleeding: the risk of serious bleeding is low. We minimise this through asking you to have blood tests before, stopping certain medications and the use of an ultrasound machine to locate the fluid.

Infection: we use anti-septic techniques to try and minimise the risk of infection. Air into the pleural cavity (pneumothorax): the risk of this is low. If a small amount of air enters the pleural cavity you may need to return to the Medical Day Unit after 1 – 2 days to have a repeat chest x-ray. If a large amount of air is present, then you may need to be admitted to the hospital and have a chest tube inserted.

Internal organ injury: there is a small risk of injury to the lung or other internal organs, including the heart, liver, and spleen. This risk of this is reduced using ultrasound.

Pain: the local anaesthetic can sting, and you might feel a ‘catch’ as the needle enters the pleura. However, this will last less than one minute, and most people do not find the procedure very painful.

Before the procedure

  1. You will need to have a blood test to check that you blood clots normally. This will usually be completed before the day of the procedure
  2. Some medications increase the risk of bleeding, for example Aspirin, Clopidogrel, Heparin, Apixaban, Rivaroxaban, Dabigatran and Warfarin

Please inform the doctor if you are taking any of these medications as soon as possible as they may need to be stopped beforehand.

On the day

  • You can eat and drink as normal and take all your regular medications (unless you have been advised by your doctor to stop certain medications)
  • Come to the Medical Day Unit, which is on the 6th Floor Esher Wing (see map)
  • The procedure will be explained to you, and you will be asked to sign a consent form
  • The doctor will use cold gel and an ultrasound machine to mark a site to remove the fluid
  • The doctor will then confirm if you are having a pleural aspiration or drainage.

What are the alternatives?

A pleural aspiration gives your doctor very specific information about the nature of the fluid and what may have caused it. However, if you decide not to have a pleural aspiration, the effusion can also be monitored with the use of chest x-rays and CT scans, but the cause may not be known.

In some cases, your doctor may instead recommend you have a more invasive procedure using keyhole surgery.

If you cannot make your appointment or decide not to have the procedure please contact the Respiratory Department as soon as possible.

After the procedure

A small dressing will be applied which can be removed after 24 hours. You do not need to be escorted home and most people feel well enough to return to their usual activities by the following day.

The results of the pleural aspiration may not be available for several days. The results will be available to the doctor who asked you to have the pleural aspiration and they will usually contact you and your GP with the results. If you are under the Respiratory clinic, the results may be discussed with you at your next appointment.

If you have discomfort after the procedure it is safe to take a simple pain killer such as Paracetamol as long as you have not been asked to avoid this.

If you feel unwell, or if you develop difficulty with your breathing please either come to the following areas:

  • Medical Day Unit (between 09:00 – 16: 00) or
  • Emergency Department (other times)

The Medical Day Unit is on the 6th Floor Esher Wing. A map of the hospital can be found at:

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