Summary

• When you have a blood transfusion, it is important that you are given donor blood that is compatible with your own blood.
• A sample of your blood will be tested to identify your blood group (A, B, AB, or O and Rh factor (positive or negative)) and to see if you have any unusual red cell antibodies.
• These tests are important in avoiding any possible reactions that could make you ill.
• Once these test results are known, the laboratory will mix a small amount of your blood with the donor blood to see if there is any reaction. This ensures that the blood you receive is compatible with your own so that it can be safely transfused.

Why get tested?

If you need to have a blood transfusion it is important that you are given donor blood that is compatible with your own to avoid reactions to the blood you are receiving and possible severe illness. The laboratory will identify your blood group and look to see if you have any additional red cell antibodies. With this information they will select the blood most compatible with your own. Selecting the right blood is known as a crossmatch.

You can find out how blood is classified or grouped in blood group test and about testing for additional red blood cell antigens in red cell antibody screening.

After your blood group is identified and it has been checked for other antibodies, the laboratory will perform a third test to ensure that the blood that is going to be transfused is compatible with your own.

This final test is the crossmatch and involves taking a sample of the blood that has been selected for your transfusion and checking that there is no reaction with any antibodies that have been found in your blood.

Having the test

Sample

A blood sample drawn from a vein in the arm.

Any preparation?

None

Your results

The crossmatch test is the final check to ensure that any blood transfused to you is compatible with your own. if there is no reaction between your blood and the donor blood during the crossmatch, then this means the blood is safe to be transfused to you.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record. You and your healthcare provider can now access your results whenever and wherever needed.

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