Forum

Discontined PT for screening test of Pb blood levels

3 posts • Page 1 of 1
Discontined PT for screening test of Pb blood levels Posted: Fri Feb 27, 2015 9:51 am
I am the only one at my workplace with formal training in laboratory science. I do almost all of the work in the laboratory though my immediate supervisor, the Laboratory Director and Office Manager, fills in when I go on vacation. My lab tests almost exclusively for the presence of lead (Pb) in mostly pediatric specimens. We use three Atomic Absorption Spectrometers and one Hematofluorometer (for the rare ZPP). The overwhelming majority of our specimens are submitted on filter paper which constitutes a screening method although we report out quantitative results in as many as three signifcant figures. We also do testing on whole blood. Proficiency testing has been discontinued for the filter paper method so I am left with only indirect means of confirming our accuracy using the whole blood proficiency specimens. I have tried to start a interlaboratory proficiency program but with no support from my superiors have gotten nowhere with it. We still do a lot of QA and QC on each run but there is no formal oversight of our primary testing method through proficiency testing.

What can anyone recommend for a proficiency program for the filter paper method? We have since had a lab inspection but the inspector's advice has not been adequately communicated to me nor has anything been done about this other than to make plans for my supervisor and myself to test the same batch of 'unknowns' as a comparison study twice a year.
Thank you for your attention,
User avatar
Cynthia J.
 
Posts: 3
Joined: Fri Feb 27, 2015 7:21 am

Although this type of testing (atomic absorption) is not typically performed in the POL setting for lead and is not my expertise, I will attempt to respond to your questions.

I would suggest that you attempt to speak with your office manager or laboratory director once more to get a full explanation as to what was recommended by the inspector at your most recent inspection. I would also try to contact every commercial PT vendor to see if they offer proficiency testing samples for lead testing on filter paper. If you still cannot find an equitable solution at this point, you could either find a reference laboratory that would take filter paper specimens for your atomic absorption methodology and follow CLIA's recommendations for inter-laboratory PT testing or perform your own testing as outlined below.

Is it possible to utilize the liquid PT samples you are currently using for whole blood and place the samples on the filter paper and then perform testing on them? If so, you would be able to prove to an inspector that both sample types are being checked in a blind sample environment. If you decide to go this route, you must be careful to not perform the testing on the filter paper until after you have submitted your whole blood results to your PT program and the submission date has been closed. I would suggest that you check with your regulatory body to make sure that this is an acceptable method for PT testing.

The testing that you and your supervisor are doing on the same samples will not suffice for PT testing. It can be used though to prove competence for your annual competency reviews.
User avatar
todd.proud
 
Posts: 129
Joined: Mon Nov 10, 2014 1:07 pm

Thank you. I'll try to apply that.
Cynthia Johnson MT(ASCP)
User avatar
Cynthia J.
 
Posts: 3
Joined: Fri Feb 27, 2015 7:21 am


3 posts • Page 1 of 1

Return to Regulatory

Who is online
Users browsing this forum: No registered users and 1 guest
cron