Group & Screen

Emergency cases – Blood Transfusion Department MUST be informed by telephone – these requests will be given priority.

• Routine group and screen results will be available within 24 hours.
• Group and screens for antenatal cases will be available within 72 hours.

Cross-Match

Urgent crossmatch – Blood Transfusion Department must be informed by phone – blood should be available within 45 minutes unless; atypical red cell antibodies are detected, special requirements are identified or patient has been identified not to have any transfusion history therefore 2 sample rule would need to be fulfilled.

Non – urgent crossmatch – blood will be available for the date and time required if sufficient notice is given. If this is not possible Blood Bank will inform the ward.

Please note that some patients are serologically complicated and testing or cross-matching may have to be referred to NHS Blood and Transplant in Barnsley. In these cases, a specific turnaround time can range from 3 to 8 hours depending on the complexity of the investigation and additional samples may be requested. If blood is required more urgently contact the Blood Bank immediately.

Direct Antiglobulin Test

A Direct Antiglobulin Test (DAT) will be available within 24 hours

N.B Outside core non urgent tests will be batched to maintain efficient working practices so turn around times may be extended in these cases.

Kleihauer Test

A Kleihauer result will be available within 24 hours if the sample is received between Sunday and Friday. The results from a sample received on a Saturday will not normally be available until Monday afternoon. If the result is required urgently or the 72-hour period will be exceeded, please contact the Blood Bank.

Note – Anti-D may be issued prior to the Kleihauer test being performed. Correct samples must be received prior to issue and the patient must be contactable and made aware that if FMH result is positive, further anti-D may be required.

Cell Free Fetal DNA Testing

Requests for this test from the Antenatal Clinic are referred to The International Blood Group Reference Laboratory (IBGRL) in Bristol with a turnaround time of 14 days upon receipt in the Blood Bank.

Cold Agglutinins

Cold Agglutinins tests are not performed at Barnsley Hospital. All samples are referred to the NHS Blood & Transplant Red Cell Immunohaematology Laboratory NHSBT, Barnsley

Histocompatibility & Immunogenetic Testing

H&I laboratories at NHSBT provide services related to solid organ and stem cell transplantation, platelet immunology, the provision of HLA/HPA selected products, transfusion reactions, the investigation of HLA related disease associations and granulocyte immunology.

Group and Screen

A sample for ‘Group and Screen’ means that the patient is ABO and Rh (D) typed, screened for the presence of clinically significant antibodies and then the sample is stored at 4°C for a maximum of 7 days. During this period the sample can be used for compatibility testing at the request of the medical practitioner providing no transfusions have taken place in the previous 3-month period (for further details on sample viability see Transfusion Guidelines).

Transfusion and pregnancy may cause an immune response and units selected for crossmatching or antibody screening must take account of this. In situations in which patients are repeatedly or previously transfused, they should be screened for the development of irregular antibodies at regular intervals. Please contact Blood bank staff for further advice for these patients.

Cross-Match

Patients for crossmatch, must follow the 2 sample rule. Please see web page for 2 sample rule.

Electronic Issue of Blood – following group and antibody screen and providing that the rules for electronic issue are satisfied, blood will be issued without the need for compatibility testing (crossmatching). In these situations blood is available almost immediately.

Compatibility testing – when electronic issue criteria cannot be satisfied, compatibility testing (crossmatching) must be performed in order to provide blood. If no antibodies are identified and there are no special product requirements blood may be available within the hour for urgent requests. If an antibody is identified or the patient requires non random units i.e. irradiated, CMV Negative, the timescale for blood availability will be extend – blood bank staff will be available to determine and inform medical staff in each situation.

Transfusion and pregnancy may cause an immune response and units selected for crossmatching or antibody screening must take account of this. In situations in which patients are repeatedly or previously transfused, they should be screened for the development of irregular antibodies at regular intervals. Please contact Blood bank staff for further advice for these patients.

Please inform the Blood Bank if the need for blood changes, in order that wastage is kept to an absolute minimum.

Non-urgent requests when no problems or special requirements are identified should be available for the time and date stated on the request form. Please allow 4 hours for in-patient crossmatches and 24 hours for cold surgery.

Please contact Blood bank for advice regarding sample requirements/collection times if:

• • • an antibody has been previously identified
    • the patient has been transfused within the last 3 months

If there is a problem in provision of blood for any reason the Blood Bank will notify the ward and/or requesting clinician as soon as possible. The blood provided will normally be of the same ABO and Rh (D) type as the patient, but blood of a different type may occasionally be provided in the interests of efficient stock management.

Medical practitioners may telephone the department or send a fully completed request form to add requests for blood or blood products to an existing group and screen sample. A full audit trail must be provided in either case.

Emergency Blood

Emergency blood will only be supplied at the request of MEDICAL STAFF who should liaise with the Blood Bank and accept full responsibility for un-crossmatched blood issued. Blood will either be group O Rh D Negative or Positive or type specific depending upon degree of urgency. Also see ‘Major Haemorrhage’

Emergency Group O Flying squad blood can be found on the top shelf of the cross-match fridge.

Decision to Transfuse

The decision to transfuse must be based on a thorough clinical assessment of the patient and their individual requirements and this should be documented in the patient’s case notes.

All requests for transfusion must provide a clear, unambiguous reason for transfusion. Terms such as ‘Pre-op’, ‘Anaemia’ or ‘Low Hb’ alone are not acceptable and provide inadequate information for audit purpose.

Maximum Blood Order Schedule (MBOS)

A summary of the MAXIMUM BLOOD ORDER SCHEDULE (MBOS) can be found in the Hospital Transfusion Guidelines.

This is a guide to blood ordering for some surgical procedures. The guidelines have been approved by the Transfusion Committee and the surgical directorates.

Patient Consent

Wherever possible, a trained and knowledgeable practitioner should inform the patient or for a paediatric patient the person with parental responsibility, in a timely manner and in a way they can understand, of the reason for and also the risks, benefits and any alternatives to the transfusion. Informed consent, either verbal or written, should be obtained wherever possible and documented in the patient’s case notes.

Blood Retention

Cross-matched blood is held for 24 hours from the time and date stated on the request form and is then returned to stock and may be used for other cases. Should a transfusion regimen take longer than 72 hours, a further sample is required in order to identify those patients who may have been stimulated into producing antibodies. This will then allow further compatible units to be provided safely.

Requests for blood to surgical lists should be requested in good time (a minimum of 24 hours in advance) and during the core working day if possible.

Cold Agglutinins

Cold agglutinins testing is not performed on site and is referred to NHSBT Barnsley

The purpose of this test is to detect antibodies active at 4 ^o C. The two relevant cold antibodies most generally tested for are Anti-I and anti-i.

Cold agglutinins seem to be produced at their highest levels in individuals between 11 and 25 years of age and may be found in cases of atypical pneumonia especially where Mycoplasma pneumonia is present.

Anti-i has been reported in patients with infectious mononucleosis, alcoholic cirrhosis and myeloid leukaemia.

If the antibody is able to bind to the red cells at 37^o C, then haemolysis may result, giving rise to CHAD i.e. Cold Haemagglutinin disease.

Direct Antiglobulin Test (DAT).

The Direct Antiglobulin Test (DAT) is used to detect sensitised red cells i.e. coated with antibody. This indicates that there are circulating antibodies directed against the patient’s red cells. These antibodies can cause a haemolytic anaemia and may indicate Auto Immune Haemolytic Anaemia (AIHA) where the patient has autoantibodies or in infants, Haemolytic Disease of the Newborn (HDN) where maternal antibody (ies) have crossed the placenta.

A positive DAT post transfusion indicates that the transfused red cells are coated with antibody from the patient and will require further investigation.  The DAT is therefore an important test in the investigation of transfusion reactions, HDN and AIHA. To differentiate the reaction, monospecific AHG reagents are used. These are IgG, IgA, IgM, C3c and C3d. For infants an IgG DAT is performed.

Kleihauer Test – Fetomaternal Haemorrhage (FMH) Testing

The Kleihauer test, is a blood test used to measure the amount of fetal haemoglobin transferred from a fetus to a mother’s bloodstream.^] It is usually performed on RhD Negative mothers to determine the required dose anti-D immunoglobulin to inhibit formation of Rh antibodies in the mother and prevent Rh disease in future Rh-positive children. It is performed when the gestation period is greater than 20 weeks.

Fetomaternal Haemorrhage can occur with intrauterine death, stillbirths, abortion (including therapeutic abortion), threatened abortion, amniocentesis, cordocentesis, chorionic villus sampling, external cephalic version, abdominal trauma, antepartum haemorrhage, PV bleeding, in-utero therapeutic interventions (transfusion, surgery) and during delivery.

An anti-D immunoglobulin injection is given in specific clinical situations in a standard dose. The Kleihauer test is performed to determine whether an additional dose is required.

The kleihauer test may also be performed to detect if any foetal red cells are present in maternal circulation and thus can also help to determine whether a FMH is involved when an intra-uterine death has occurred regardless of the maternal blood group.

Cell Free Fetal DNA Testing

During pregnancy a small amount of cell-free fetal DNA is present in maternal blood. This DNA can be analysed to predict the baby’s Rh D blood group (Positive or Negative) as it assesses whether it differs from that of the mother. The test is highly accurate and can be performed from 11+2 weeks’ gestation (crown rump length > 45mm). However, owing to the sensitivity of the test, there is a small chance (0.1%) that a fetus predicted to be D negative will be D positive at birth.

This test is referred to The International Blood Group Reference Laboratory (IBGRL) in Bristol with a turnaround time of 14 days upon receipt in the Blood Bank.

Histocompatibility & Immunogenetic Testing

HLA Typing:
There are many thousands of different tissue types as a result of the differences in our HLA genes. Some of these tissue types are associated with disease including ankylosing spondylitis, Behcet’s disease, birdshot chorioretinopathy, coeliac disease, narcolepsy, rheumatoid arthritis and selective IgA deficiency. Please contact the laboratory for sample requirements.