Historically, from the invention of the antiglobulin test in 1945 to approximately 1980, antibody detection methods emphasized detecting all possible antibodies, with little or no regard for clinical significance. Similarly, elaborate investigations involving adsorptions and elutions were often done whether or not the results would influence patient care.
Since the 1980s and particularly in the 1990s, one trend has been to decrease testing consistent with patient safety by doing only those tests that will have a clinical impact. This means, for example, that pretransfusion tests are designed to detect only clinically significant antibodies; that testing for weak D in the Rh system (Du testing) is inappropriate for transfusion recipients; that doing elutions on healthy newborns who have positive direct antiglobulin tests likely due to antibodies in the ABO system is of little value; and that doing antiglobulin crossmatches for patients who lack unexpected antibodies has limited clinical utility. See, for example, this Medline abstract of a 1992 paper by Heddle et al. on the safety of omitting the antiglobulin crossmatch.
Similarly, methods for antibody screening that tend to detect cold antibodies have decreased in use. These include using polyspecific antiglobulin serum; protease-treated red cells; and immediate-spin phases at RT.
Another trend has been to select methods for pretransfusion testing that have a decreased incubation period and thus a better turn-around time (TAT). For this reason, antibody screening methods using low ionic strength saline (LISS), gel, ReACT, SPAA, and PEG (all of which have a 10-15 minute incubation) have become popular.
To reduce TATs further, pretransfusion tests have become streamlined. Streamlining encompasses using a maximum surgical blood order schedule (MSBOS) to enhance efficiency of pretransfusion testing . It also often involves replacing the indirect antiglobulin crossmatch with donors (for patients who lack unexpected antibodies) with an immediate-spin RT crossmatch or a computer-assisted crossmatch.
See electronic crossmatch for a brief review.
There is also a move to methods that can be automated or semi-automated (e.g., SPAA, gel) and that facilitate streamlining and batch testing (e.g., the computer-assisted crossmatch). By decreasing staff requirements, these methods are seen as contributing to cost-effectiveness in an era of severe budget cutbacks. In general, to make automation cost-effective in the blood bank, large-scale testing is required; this in turn requires transfusion services to regionalize and to centralize.
Cost restraint and cut backs have motivated transfusion services to regionalize and to centralize. Typically, a centralized transfusion service performs all routine and complex testing; satellite labs are restricted to STAT tests that require rapid turn-around times.
An example of a centralized transfusion service is the Institute for Transfusion Medicine in Pittsburgh.
Centralized testing has further led to wired transfusion services, in which centralized laboratories communicate with satellite "rapid response labs" via a shared laboratory information system and intranet. In this scenario, serological pretransfusion testing is done at the central lab and the rapid response lab performs electronic crossmatches on-site.
E-mail responses to Questions #-#3 to Pat.
Visit this MSBOS used by the transfusion service at the London Health Sciences Centre in Ontario, Canada. Note that London uses the term "G & R" (group & reserve) as a synonym for type and screen. Based on the information, answer the following questions:
(a) Total hip replacement
(b) Cholecystectomy & cholangiogram
(c) Hiatus hernia
(d) Abdominal hysterectomy & appendectomy
E-mail responses to the following questions to the class mailing list.
(b) If no, briefly explain some of the reasons why they have not been adopted.
(b) If an MSBOS is not used, briefly indicate some of the reasons why it has not been adopted.
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