Normal Ranges for Blood Bank tests

[tricore]

Has anyone ever seen "normal" ranges published for blood bank results?

[SMILLER]

No, but I suppose you could have a reference range for things like a DAT (negative) or even a crossmatch result (compatible).

 

Scott

[kate murphy]

I'd be careful defining a "normal" range for even those tests.  You might have to adhere to critical alerts and call back workflows, as well as ranges for different age groups, racial groups, male/female, etc.

I know I'm a dinosaur, but I always thought a normal range refers to results that may vary in a normal population and  what you would compare patient results against - numeric values.  There really isn't a "range" of values that we compare BB results against.  Even an atypical antibody, while atypical, is not "abnormal".  Kind of gives the impression that eventually, the result will revert to "normal".

[tricore]

Has anyone ever been cited by CAP for not having "Reference intervals" for BB results? I have not. Personally I don't think there should be published reference Intervals for BB tests. I was asked this question. Someone told our BB computer vendor that "CAP was expecting" these. I guess they wanted to put the "normals" into the BB reports from the LIS.

COM.29950 Reference Intervals Phase II

All patient/client results are reported with reference (normal) intervals or interpretations

as appropriate.

NOTE: The laboratory must report reference intervals or interpretations with patient/client results,

where such exist. This is important to allow proper interpretation of patient/client data. Ageand/

or sex-specific reference intervals or interpretive ranges must be reported with patient

test results, as applicable. In addition, the use of high and low flags (generally available with

a computerized laboratory information system) is recommended. It is not necessary to include

reference intervals when test results are reported as part of a treatment protocol that includes

clinical actions, which are based on the test result.

Under some circumstances it may be appropriate to distribute lists or tables of reference intervals

to all users and sites where reports are received. This system is usually fraught with difficulties,

but if in place and rigidly controlled, it is acceptable.

Edited February 9, 2017 by tricore
added information

[John C. Staley]

It's been years since I have heard this discussion come up.  My answer has always been that there is nothing normal about blood banking so how on earth can we have normal values!   Sorry, sometimes my fingers get carried away.

 From my perspective the concept of normal values does not apply to the blood bank world.  I agree fully with what Kate Murphy said above.

[MOBB]

I think the qualifier "as appropriate" covers the blood bank's lack of normal ranges.

[exlimey]

Oh, my. I can't even begin to imagine what such a document would look like. There is so much grey/gray in transfusion medicine, especially in the testing realm, that any document would be as complicated and of as little use as the US Tax Code.

For example:

Positive DAT - abnormal; except when one or more of the following conditions exist: [add your list of 50+ reasons for a positive DAT]

You would be listing so many ifs, ands, or buts, that any document would be practically useless.

My vote echoes MOBB: Use the "get-of-jail" phrases like "as appropriate" and "where such exist".

[Marianne]

or interpretations as appropriate

the back half is what would apply for Transfusion.  You have interps, Pos, Neg, A, B........................as applicable.