Patient information from BMJ

Ascitic tap and ascitic drain procedures

Last published:Dec 09, 2022

These two procedures are similar, but there are a few differences. They both involve taking fluid from your abdomen when extra fluid has built up.

You can use the information in this leaflet to discuss these procedures with your doctor.

What is an ascitic tap and an ascitic drain?

Your.abdominal cavity is the space between the skin, muscle, and other tissues of your abdomen, and your internal organs, such as your intestines (bowels).

Your abdominal cavity is hollow. But there is always a little fluid in there. Some medical problems can cause a lot of fluid to collect, causing swelling and pain. This fluid is called ascites.

Ascitic tap

If your doctor needs a sample of the fluid in your abdominal cavity for testing, you may have a procedure called an ascitic tap.

This involves taking fluid using a needle - a bit like when you have a blood test.

Ascitic drain

If a lot of fluid has built up in your abdominal cavity, and it is causing you to become uncomfortable, you may have a procedure called an ascitic drain.

You may also hear both of these procedures called paracentesis.

What happens in an ascitic tap procedure?

• You start by putting on a gown and lying on your back.

• The doctor or nurse finds a good spot on your abdomen to take the fluid. This will be on your right or left side, about halfway in towards your navel (belly button), but lower down. You may have an ultrasound scan first, to find the right place. An ultrasound is a quick, painless scan, just like pregnant women have to show images of their baby.

• You will be awake during the procedure. But your doctor or nurse will give you two injections of local anaesthetic to numb the area: one near the skin surface, and one in the deeper tissue. These injections should stop you from feeling any pain during the procedure.

• The doctor or nurse will then use a needle to draw out a small amount of fluid for testing.

• They will then apply a dressing over the injection site, and the procedure is over.

What happens in an ascitic drain procedure?

The first steps of this procedure are the same as with an ascitic tap. The procedure is done in the same spot, and you have two injections of local anaesthetic. After that:

• The doctor or nurse makes a small cut with a scalpel, just big enough to carefully insert a thin tube into your abdomen. This is the drain

• Inserting the drain through the muscle and other tissues in your abdomen can take several minutes

• The doctor or nurse will attach a collection pot or bag to the drainage tube and secure it in place. The drain may need to stay in for several hours

• Once the fluid has stopped draining, the doctor or nurse will remove the drain. They will and apply a dressing over the cut. They may also close the cut with a stitch.

Why may I need these procedures?

An ascitic tap procedure is often done to find the cause of the fluid building up in your abdomen. For example, testing a sample of the fluid may show you have an infection called peritonitis. This is an infection of the lining of your abdomen, usually caused by damage to the bowel.

Other things that can cause a build-up of fluid in the abdomen include problems with the heart, kidneys, and liver, and some cancers. Testing the ascites can help to identify the cause.

An ascitic drain procedure is used to remove the excess fluid if it is causing pain, discomfort, or breathing problems.

Not everyone is able to have these procedures. For example, you may not be able to have them if you:

• Are pregnant

• Have a bowel obstruction or other intestinal problems

• Have a skin infection such as cellulitis near where you would need to have the injection or cut, or

• Have a condition that affects how easily your blood clots. The medical term for this is coagulopathy.

What are the risks?

These procedures are considered safe for most people. But problems can sometimes happen. These can include:

• Bleeding

• Fluid leaking from the tap/drain site

• Infection

• Damage to your internal organs during the procedures

• Low blood pressure from large amounts of fluid being removed

• Fluid building up again so that you need to have another ascitic drain a few weeks or months later.

If you have problems such as bleeding, infection, or low blood pressure, you may need to have treatment.

What can I expect afterwards?

You will need to have some blood tests repeated the day after the procedure. You will probably also have your fluid levels checked again.

If the fluid drained from your abdomen was sent for testing, your doctor will use the results to work out the cause of your ascites (if it wasn’t known already). You may then receive treatment for the underlying cause.

You should recover from an ascitic tap procedure fairly quickly. You can take painkillers such as paracetamol if you need to.

It will probably take a few days to fully recover from an ascitic drain procedure, as the wound will take a little longer to heal.