Venepuncture and blood tests

Introduction

Venepuncture is when blood is taken out of your child’s vein with a needle for testing. Your child’s treatment team might just call this a blood test.

In a blood test, blood is removed from your child and is sent to a lab for testing. It is tested by a specialist doctor called a pathologist.

Blood tests are used to check for:

• different diseases
• infections
• check levels of things like vitamins and hormones.

Some things can only be checked by a blood test.

Your child’s doctor or nurse will explain why the test is needed and what it is checking for.

Some children do not like needles, this is normal.

Ask your child’s doctor or nurse whether they can use a special cream to lower any pain from the needle. This cream can take about 30 minutes to work, so it can only be used if the blood test is not urgent. Special creams might not be available from your local blood testing centre, so it’s important to call beforehand to check.

Generally, the steps of venepuncture for a blood test are:

1. you or your child, depending on their age, will be asked to check the details on some stickers that will be used to label the blood samples
2. an elastic belt called a tourniquet is put around your child’s arm and is pulled tight to help show where a good vein is
3. the skin over the vein is cleaned with a small alcohol swab
4. a needle is put into the vein and blood is taken quickly into several vials.
5. Once the blood is collected, the needle is removed and a cotton ball is pressed on top to stop the blood from flowing.

Your child will need to try and sit still while their blood is being taken. A nurse may need to hold your child’s arm to stop the needle from moving or coming out. This is for your child’s safety and to avoid having to do a second venepuncture.

A second venepuncture might need to be done if:

• a vein can't be found
• not enough blood can be obtained
• your child moves and the needle comes out of the vein.

Veins can be difficult to find in small children, and those who are very young or very chubby, like babies and toddlers.

Parents and carers can stay with their children to support and distract them during the venepuncture. If a parent or carer isn’t available, a member of your child’s treatment team will be there for support.

There can be some soreness and bruising after the venepuncture, depending on how easy the vein was to find and whether there was any movement. This should go away quickly.