The crossmatch is defined as a procedure to exclude incompatibility between donor red cells and the patient’s plasma
For babies < 4 months old, a maternal sample is required to check for red cell antibodies
- If the maternal sample does not contain any red cell antibodies, then Group O Rh D negative red cells can be issued electronically without serological crossmatch.
- If maternal red cell antibodies are present, then the red cells selected must be compatible with the maternal allo antibodies and a crossmatch using maternal plasma must be performed.
- For non-urgent cases, samples should be sent to the laboratory at least 24 hours before any transfusion requirement
- If blood is required urgently, and there is no valid group and save in the laboratory, a full serological crossmatch will take approximately 40 minutes on following receipt of sample in the laboratory.
- If a patient has been transfused or pregnant within the last 3 months, then the sample is only valid for 3 days, which is from the time the sample is taken to the subsequent transfusion.
- If a patient has NOT been transfused or pregnant within the last 3 months, then the sample is only valid for 7 days.
- Where difficulties arise in the provision of blood, the Transfusion laboratory will contact the clinician to discuss further
- The Transfusion IT system will inform you if there is a valid sample in the laboratory and if the patient is eligible for electronic issue or not, or if a new sample is required.
- Samples may need referral to NHSBT Filton, Bristol for further investigation
- This test is performed at GRH and CGH
Sample and request form must be labelled correctly with 4 points of patient identification reference:
- First name
- Date of Birth
- NHS or Hospital Number
Unlabelled, wrongly labelled or inadequately labelled specimens will not be accepted. No specimen is considered unrepeatable.
Immediate Emergency Group O negative (females) and O positive (males only)
5 mins Electronic issue (providing eligibility criteria met)
15 mins ABO compatible blood
40 mins Fully crossmatched blood
Author: Stuart Lord, Transfusion Practitioner
Reviewed date: 14/03/2023
Next review date: 14/03/2025