This involves drainage of fluid from around the lung through a needle or plastic tube. This is guided into place using an ultrasound, CT or X-Ray machine.


In ultrasound you will usually be seated on a bed, resting on a pillow or table. The ultrasound will be used to identify a suitable position for drainage. Your skin will be cleaned with antiseptic and local anaesthetic will be given.

For a diagnostic tap the radiologist will insert a fine needle to obtain a sample of fluid. When the needle is removed a small dressing is placed on the skin.

For a pleural drain a small incision is made in the skin. A needle is usually inserted first and then a wire and a plastic tube which can be left in to drain the fluid. It may be necessary to make more than one pass of the needle to achieve adequate placement.

The tube will be held in position by a dressing on the skin.

Most commonly a short stay hospital admission is arranged to allow fluid to drain over several hours.

The drain may stay in overnight if you are an inpatient. Rarely, the tube is left in for longer periods.

The drain can be removed easily on the ward and a small dressing applied.

Risks / Side Effects

Potential risks include infection, bleeding and air leak.

  • Aseptic technique is used to minimise the risk of infection as much as possible.
  • The needle may puncture a blood vessel. Rarely, excessive bleeding can occur and may require drainage, transfusion or surgery.
  • The needle may puncture the lung, allowing air to leak out into the surrounding space. If small, this will be followed up without treatment. If large, a chest drain may need to be inserted.

Before your Scan

It is essential that your previous x-ray, CT or ultrasound films are available at the time of the drainage. If you have them, please bring these with you to your examination.

Please inform us if you are on medication to thin your blood (eg. Warfarin, Aspirin or Clopidogrel). You may need to stop this prior to the procedure after discussion with your doctor.

It is important that you have someone to drive you home after the procedure.

Other Information

Once the drain is removed a dressing will be applied. There may be a small ooze from the site which should stop after a few hours.

You should avoid strenuous activity for 24 hours following the drainage.

You may experience some discomfort.

  • If required, a simple analgesic such as paracetamol (Panadol), NOT Aspirin, should be sufficient.

Potential complications include infection and air leak. If you notice any increasing redness, swelling, fever or pain around the drainage site, or increasing shortness of breath or pain on breathing, notify your referring doctor or call the clinic where the drainage was performed immediately.

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