Crossmatch

Keywords: Compatibility test, Xmatch, CXM, Xm, Pre-transfusion compatibility testing

Specimen:

10 mL blood in plain tube; for some methods, blood in EDTA is preferred.

Patient's identity must be positively confirmed at time of sample collection (that is, asking the patient to state surname, given names and date of birth and check ID labels are fastened to the patient's wrist). Three approved patient identifiers (eg, surname, given names (in full), record number or date of birth) and date and time of collection, and signature or initials of collector are required.

Method:

Blood group and serum antibody screen performed; ABO and Rh(D) matched donor blood selected.

Recipient serum tested against donor red cells by indirect antiglobulin test and one other technique (eg, saline, Polybrene, enzyme).

Crossmatch may be replaced by an immediate spin compatibility test if the recent blood group antibody screen is negative.

See also Blood group and Blood group and antibody screen.

Application:

Selection of compatible blood for transfusion.

Details of specific transfusion requirements, including date of procedure, urgency of requirement and patient location is required for the laboratory.

Refer to the laboratory for details of the duration of validity of the routine cross-match specimen.

Interpretation:

Compatibility confirms matching of blood donor and recipient and excludes the possibility of immediate haemolytic transfusion reactions. Delayed haemolytic transfusion reactions and febrile (non-haemolytic) reactions may still occur.

Uncrossmatched, or even incompatible, blood may be issued in life-threatening emergencies, even when alloantibodies are known to be present, if there is no compatible blood available. Consultation with haematologist is recommended.

Reference:

Napier JA. 1991; 78: 1-4.

Guidelines for Pre-transfusion Testing. 4th ed. Australasian Society of Blood Transfusion 2002.

Australian Commission on Safety and Quality in Health Care (ACSQHC) National Safety and Quality Health Service Standards. ACSQHC, Sydney, 2011.