Pre‐transfusion testing

Abstract

The first step in successful pre‐transfusion testing is receipt of timely requests for blood with adequate clinical details and correctly labelled samples, to enable the laboratory to provide compatible blood components, that meet any special requirements for the patient, e.g. irradiated, phenotyped. Establishing compatibility and suitability of blood for a patient is a complex process including: sample acceptance; checking historical records; testing for ABO/D; antibody screening and identification; serological or electronic crossmatching; selecting appropriate blood components; labelling and issue.The specifications for routine serological testing and final method of establishing compatibility will depend on the resources available, and on national policy and guidelines. Variability in resources includes: access to historical records; standard of reagents available for serological testing; level of IT; use of automation; and availability of staff with specialist transfusion training. Different testing protocols may be required for specific groups of patients such as neonates, transfusion dependent patients and transplant recipients.Quality assurance is essential throughout the process. The risk of error in pre‐transfusion testing varies considerably depending on the combination of tests and procedures selected together, and a risk assessment of the overall process is advisable. A higher proportion of errors occur ‘out of hours’, where staff are working under pressure, and may be using non‐routine techniques. Safety can be improved by managing emergency and ‘out of hours’ requests, and applying ‘maximum blood ordering schedules’ to reduce unnecessary crossmatching. Well designed procedures and policies can do as much to improve safety as accurate and sensitive techniques.