A colleague at a Transfusion Service in Tennessee reports that her hospital does not draw its own blood donors. Consequently they obtain all of their platelets from a regional blood supplier who provides them with a mix of both pheresis and random platelets. The supplier performs cultures on the pheresis platelets, but not the random platelets. In order to comply with AABB and CAP accreditation requirements to detect bacterial contamination in all platelet components, her hospital has chosen to use urine dipsticks to measure the pH and glucose of the random platelets before pooling them for transfusion. If the pH of a random platelet unit is less than 7.0 or if the glucose is less than 250 mg/dL, they return the platelets to the supplier.

Recently, one of their supervisors attended a CAP inspector training class in which the question was raised as to how one should perform proficiency testing for urine dipstick testing of platelets. They were told that an applicable proficiency testing module was not available, but that they should perform split sample testing to document proficiency. While this sounds easy, the Tennessee colleague laments that the devil is in the details. She would like to know if other institutions are performing split sample testing for in house proficiency testing of bacterial detection using urine dipsticks, and if so, exactly what is their procedure?

ADDENDA Mar. 14, 2005

The following comments have been received.

1. The Editor provides this CAP reference:

The CAP Laboratory Accreditation Checklist, item GEN.10500 (Phase II) asks "For tests for which CAP does not require enrollment in PT (proficiency testing), does the laboratory at least semiannually:

1. participate in external PT, or
2. exercise an alternative performance assessment system for determining the reliability of analytic testing?"

The NOTE that corresponds to this question (item #2) states: "Appropriate alternative performance assessment procedures may include: participation in ungraded/educational proficiency testing programs, split sample analysis with reference or other laboratories, split samples with an established in-house method, assayed material, regional pools, clinical validation by chart review, or other suitable and documented means. It is the responsibility of the Laboratory Director to define such alternative performance assessment procedures, as applicable, in accordance with good clinical and scientific laboratory practice. As an example, the biannual CAP CED educational challenge in esoteric coagulation testing offers an opportunity to compare test results with other participants."

Here is the link to the above (MS Word).

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator