One of the complications of blood transfusion is that the patient may develop a new red cell antibody. Red cell antibodies may cause a serious transfusion reaction if incompatible blood is given to the patient. If there is a gap between transfusions then a new sample is required to check whether a new antibody has developed.

For repeat transfusions the following applies:

Patients Transfused Within the Last 3 Months

Samples collected no more than 72 hours prior to the actual transfusion when the patient has been transfused or pregnant within the preceding 3 months.

ROH, QEHB and Pre Assessment Clinics

The samples from patients attending QEHB and ROH pre-op assessment clinic are stored for 4 weeks. It is important that pre-operative assessment clinic nursing staff inform patients that a condition of keeping the transfusion sample for 4 weeks is that patients must inform the ward upon admission that they have had a transfusion elsewhere or are or have been pregnant. In these cases, a new transfusion sample must be taken. Samples which contain antibodies require a FRESH sample for crossmatch.

Renal

If a patient attending the dialysis unit as an out-patient has a sample taken during the visit, providing no transfusion was given at the same visit, this sample can be used. If a transfusion was given then a fresh sample MUST be taken no more than 72 hours before the next transfusion episode.

Cardiac Clinic

The samples from patients attending cardiac pre-op assessment clinic are stored for 4 weeks during which time some patients may have received top up transfusions pre–op. As a precaution when the cardiac list arrives check each transfusion history.

Haematology Day Unit

The requests for cross-match from patients attending Haematology Clinics are for in-patient treatment during the next few days and providing the patient has not been transfused for 3 months prior the sample being taken then this sample is safe to use. If the patient has been transfused during the last 3 months then a fresh sample MUST be taken no more than 72 hours before the next transfusion episode unless the consultant concerned authorises the use of the sample.

Liver

Liver samples are kept for seven days in the specimen fridge. Treat as a routine group and save sample.

IF IN DOUBT IT IS SAFER TO REQUEST A FRESH SAMPLE