Haematology
This information leaflet is about a procedure called a venesection which may be required as part of your treatment for a blood condition.
Please speak to your doctor or clinical nurse specialist if you have any questions or concerns, or would like more information about the condition you have and how it is treated.
What is a therapeutic venesection?
Therapeutic venesection is the removal of a quantity of blood from a vein (usually 450mls) and is used as a treatment for certain blood conditions.
What are the benefits of therapeutic venesection?
A venesection is a simple and effective way of reducing the number of red blood cells in your blood. This may be needed to reduce iron levels or the thickness of the blood to safe levels.
What conditions are treated with therapeutic venesection?
Therapeutic venesection is commonly used to treat:
- Haemochromatosis
This is a genetic condition where your body absorbs too much iron. Excess iron is stored in various organs around your body such as the heart and liver which can lead to problems or damage to the organs. As large amounts of iron are contained within red blood cells the simplest way to remove iron is to take blood from you at regular intervals. - Polycythaemia vera, erythrocytosis and high haemoglobins
With these conditions your body has an increased number of red blood cells which thicken your blood and make the blood flow ‘sluggish’. This can then increase the chance of developing problems such as a thrombosis (blood clot).Removing the extra red blood cells reduces the risks.
Are there any alternatives to venesection?
Your doctor has recommended venesection as the best way to treat you. If you would like more information on possible alternative treatments please do not hesitate to speak to your doctor or specialist nurse.
How many venesections will I need?
This will be different for each person and is dependant on your condition and your blood counts. You may need therapeutic venesections on a short term basis or over a period of many years. At first you may need the treatment every week. Once your condition is under control you may need to come less often.
Unfortunately, there is no way of predicting at the outset how often you will need a venesection as this will depend on how you respond. Your blood tests will monitor your response and your nurse will explain when and where your blood tests will be monitored.
Where does the procedure take place?
The venesection is usually carried out in the haematology day unit at The James Cook University Hospital or in the Mowbray suite at the Friarage Hospital.
You may be at the hospital for approximately an hour. The actual venesection takes about 15 minutes but you will need to stay in the day unit for a short while afterwards. This is so that we can make sure your blood pressure is stable and you feel well.
Is there anything I need to do to prepare for the venesection?
No special preparation is needed prior to this test, although we recommend that you have something to eat and drink before coming for your venesection.
You do not need to bring anything in particular with you. There is no reason why you should not drive, or continue with normal activities before, and after, the test. We would however recommend that you do not drive when you come to hospital for your first venesection treatment. You may feel light-headed or dizzy afterwards.
As with any hospital visit you may feel anxious and may like to bring someone with you to keep you company.
How is a venesection performed?
Before your first venesection is carried out, the procedure will be explained to you by your doctor or specialist nurse. The venesection procedure is similar to that of donating blood.
A nurse, or trained practitioner, remains with you throughout the procedure. Following the procedure most people carry on as normal after they have left the unit. Some people, however, do feel a little ‘washed out’ for a couple of days afterwards.
You should :
- Drink extra fluids for the rest of the day
- Try to not smoke for at least two hours following your venesection
- Avoid drinking alcohol
- Avoid strenuous exercise
- Try to rest
Some patients may need to be given extra fluids whilst having a venesection. This will be given by an intravenous drip in a vein in the opposite arm. This is usually requested by your doctor if you have a history of low blood pressure or have felt light-headed or faint during or after a previous venesection.
Is it painful?
You may feel some discomfort when the needle is inserted but it should not be painful. If it feels too uncomfortable please tell the nurse performing the venesection.
How long does it take?
The collection takes about 15 minutes. When it is completed the needle is removed, pressure is applied for a few minutes and a small dressing put on. You will be offered a drink and asked to remain in the unit for about a further 20 minutes. However you may need to stay longer if any problems occur.
Are there any risks or side-effects associated with venesection?
Light-headedness or fainting
Sometimes people can feel light-headed, dizzy or have blurred vision during, or shortly after a venesection. If this happens it is important that you tell your nurse immediately.
Resting for a short while following the venesection and making sure you have something to eat and drink before the venesection can help to prevent this.
Bruising
You may have a bruise where the needle has been inserted and this will disappear after a few days. You should avoid lifting heavy objects with this arm for 24 hours following your venesection.
Bleeding from the needle insertion site
After removing the needle the nurse will apply pressure to the site and a dry dressing will be applied. Occasionally the site can start to bleed after you have left the day unit. If this happens please apply pressure directly over the insertion site for several minutes until this has stopped.
If a person is taking tablets that thin the blood, for example;. Warfarin, we may ask you to stay a little longer to check there is no bleeding before you leave the unit.
Anaemia
If you are having venesections you may become anaemic. Anaemia is when you have less haemoglobin than normal in your red blood cells and when this happens your blood cannot carry the full amount of oxygen around your body. This can make you feel tired or faint causing headaches and breathlessness. If you do develop anaemia this can be easily treated and we will reduce the frequency of your venesections.
Scarring from long-term needle insertions
We will try and use alternative veins to reduce the risk of long-term scarring but this is often unavoidable. Your nurse will discuss which veins are suitable for use when having your venesections.
Can I return to work after the venesection?
You can return to work as long as you feel well and do not feel faint or light- headed. Please discuss this with your doctor or specialist nurse. You should inform your employer that you are returning to work following venesection treatment.
Can I drink alcohol?
Alcohol can cause dehydration and it is important to avoid becoming dehydrated, particularly prior to your venesection.
Alcohol can also increase your risk of bruising or bleeding following your venesection. We therefore recommend that you avoid alcohol the day before and on the day of your venesection.
Can my blood be donated?
Although the venesection procedure is similar to that of a blood donation we cannot use your blood for this purpose and it is always disposed of. If you would like to be a volunteer blood donor details can be found on the Give Blood website.
You can discuss this with your doctor or specialist nurse. If you do donate blood, please inform us at your next clinic visit as we need to keep a record of how much blood is being taken.
Further advice or information
If you are worried or concerned following the procedure or if you would like any further advice or information please do not hesitate to ask – we will be more than happy to help. It may help to make a note of any questions you want to ask.
Contact us
You can contact the haematology nurses on the following numbers:
The Chemotherapy Day Unit
Sir Robert Ogden Macmillan Cancer Centre
Friarage Hospital
Telephone: 01609 764532
(Monday to Thursday, 8.30am-4.30pm)
Haematology Day Unit
The James Cook University Hospital
Telephone: 01642 854273
(Monday to Friday, 9am-5pm)
Sources of information
Patient experience
South Tees Hospitals NHS Foundation Trust would like your feedback. If you wish to share your experience about your care and treatment or on behalf of a patient, please contact The Patient Experience Department who will advise you on how best to do this.
This service is based at The James Cook University Hospital but also covers the Friarage Hospital in Northallerton, our community hospitals and community health services.
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T: 01642 835964
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