Outpatients - Blood Tests: What you need to know

Blood Tests

Your hospital doctor or specialist nurse may have asked for you to have a blood test to help them in the treatment and monitoring of your illness.

Important Points to Note:

• If your blood sample request card or online request is not fully completed by the clinician, the blood test may not be able to be carried out and you will be asked to return to the clinician to have this information included. This is a legal requirement
• Please note that the waiting time in the Blood Sampling/ Venepuncture Room may vary and can, on occasion, be lengthy due to demand for this service
• The service is available Monday to Friday 8:30am to 3:30pm
• Closed Weekends and Bank Holidays

Who will take my blood?

Your blood test will be undertaken by a phlebotomist, who is specially trained in this procedure, or a nurse who has had similar training.

The procedure is called venepuncture.

Things I need to do

Please:

• Tell the person taking your blood sample if you take any medication that thins the blood (such as Warfarin or Aspirin)
• Advise the phlebotomist if you have experienced difficulty in obtaining blood previously
• Say if you have a preference for which arm is used
• Tell the phlebotomist if you are afraid of needles or the sight of blood
• Advise the phlebotomist if you have felt faint or actually fainted when having blood tests previously
• Keep your arm straight throughout the procedure and immediately afterwards
• State immediately if you feel intense pain or burning
• Apply pressure to the puncture site and keep the pressure applied for 20 – 30 minutes
• Keep the dressing on for at least one hour

Things I need to know before I have a blood test

Venepuncture is a mildly invasive procedure that involves puncturing a vein to obtain blood and is not without risk.

It is common to have a small amount of bruising after the procedure, due to bleeding under the skin. This is normal and should resolve after a few days. However, if the area becomes red or swollen seek advice from your GP.

Occasionally the arm may have a large area of bruising. This is usually due to insufficient pressure having been applied once the needle has been removed or through damage to the vein when the needle has been inserted due to fragile veins.

Although this can be painful, it usually resolves itself within a few days. Patients taking anticoagulants will bruise more easily.

Another complication of the procedure can be tendon or nerve damage, when access to the vein has been compromised.

Please advise the phlebotomist if you feel any exceptional pain at the time of needle insertion as the procedure will be stopped immediately.

Medical advice may be required as damage to nerves and tendons can take weeks to resolve.

How will my sample be taken?

• You will be asked to sit in a chair and expose the inner side of the elbow. This is the only area where phlebotomists will attempt to take your blood
• The phlebotomist taking your blood sample will confirm your name, date of birth and address and will cross check these with the details on the card
• It is important that the phlebotomist confirms your identity. However, if you are a carer/parent of the person who requires the blood test you may be asked to confirm their details, if they are unable to do so themselves
• The phlebotomist will examine your arms to see if you have a suitable vein from which they can obtain the sample
• A tight band called a tourniquet will be put around the upper part of the arm. This temporarily slows the blood flow and causes the vein to swell so that the sample can be obtained
• The phlebotomist will cleanse their hands and apply gloves
• The skin area is then cleansed with an alcohol based wipe to reduce the risk of infection and allowed to dry
• As the needle is inserted you should feel a slight pricking or stinging feeling. The blood is drawn back slowly. It may be that more than one bottle will be required, however only one needle will be inserted if the procedure is problem free
• If you feel faint at any stage of the procedure you must tell the phlebotomist, who will take action to make you more comfortable or will stop the procedure
• When all the samples are obtained, the needle is removed and a gauze pad is applied with a little pressure to stop the bleeding and to prevent bruising. Your arm should be kept straight whilst the pressure is applied. Bending the arm can cause bruising. The phlebotomist may ask you to apply the pressure whilst they transfer your details onto the sample bottles before that are sent to the laboratory
• The phlebotomist will check the site again and apply tape over the gauze dressing which must be kept in place for an hour before you remove it