College of American Pathologists
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  Queries and comments


October 2002
Originally published in CAP TODAY

Hundreds of questions roll in each year about Laboratory Accreditation Program requirements. CAP TODAY continues to publish a sampling of those questions and their answers, written by LAP checklist commissioner Albert Rabinovitch, MD, PhD, of Marina Del Rey, Calif. As head of all LAP checklist activity since 1993, Dr. Rabinovitch has years of experience and insight we're pleased to share.

Q: It was with interest that I read question GEN. 40530 in the 2001 laboratory general checklist, which reads, "Is there a documented tracking system to ensure that all specimens submitted to the laboratory are actually received?" Was the need to maintain specimen quality your primary motivation for including this question? Does this inclusion signal an expansion of the CAP's focus to include good business practices in outreach support operations? If so, will the CAP provide resource information to laboratories found deficient in this area?

A: The new question relates to the expansion of pre- and postanalytic arenas for clinical laboratories. Our traditional focus has been on issues within the physical laboratories, but this does represent expansion because more specimens are traveling short and long distances to and from laboratories. Clearly, there are valid concerns about specimen quality in the preanalytic milieu. So, I suppose we are expanding outside the traditional laboratory walls, given the realities of changes in the health care environment. The CAP would never direct laboratories to any specific commercial source for resource information, if that is the thrust of your last question. Conversely, if you can provide specific citations from the peer-reviewed literature that speak to this checklist question, I would be pleased to consider including them in a future edition.

Q: I am a point-of-care testing coordinator and have questions about the responsibility of competency testing of nonlaboratory personnel for phlebotomy technique. If the phlebotomy is not performed by laboratory personnel and the samples are sent to the laboratory for testing, who is responsible for competency and training?

A: Accreditation is limited to the laboratory accredited by the CAP, which obviously includes all laboratory employees. Each organization has its own administrative structure, with various reporting relationships involving nonlaboratory phlebotomists. In the latter case, it is clearly beneficial for knowledgeable laboratory personnel to participate in the training and competency assessment of such individuals, but that is not required for purposes of CAP accreditation. However, if poor sample quality results from collections by phlebotomists, then a CAP-accredited laboratory has a quality improvement basis on which to address any such problems in the preanalytic arena.

Q: Is the Allen's test still required for performing an arterial blood gas puncture—and, if so, does it have to be documented anywhere that the Allen's test was performed?

A: Question AGC.22400 was modified for the current edition of the automated-general chemistry checklist to read, "For radial artery sampling, is a test for collateral circulation performed before arterial puncture, as applicable? Note: The various technologies available have been evaluated in the published literature. Consensus should be established between the laboratory and involved clinicians to define in which patients and under what circumstances such a test is medically useful in averting potential patient injury."

The references provided in the checklist are:

  1. Vaghadia H, et al. Evaluation of a postocclusive circulatory hyperaemia (PORCH) test for the assessment of ulnar collateral circulation. Can J Anaesth. 1988;35:591–598.2
  2. Cheng EY, et al. Evaluation of the palmer circulation by pulse oximetry. J Clin Monit. 1989;5:1-3
  3. Levinsohn DG, et al. The Allen's test: analysis of four methods. J Hand Surg. 1991;16:279–282.
  4. Fuhrman TM, et al. Evaluation of collateral circulation of the hand. J Clin Monit. 1992;8:28–32.
  5. Fuhrman TM, et al. Evaluation of digital blood pressure, plethysmography, and the modified Allen's test as a means of evaluating the collateral circulation to the hand. Anaesthesia. 1992;47:959–961.
  6. Fuhrman TM, McSweeney E. Noninvasive evaluation of the collateral circulation to the hand. Acad Emerg Med. 1995;2:195–199.
  7. O'Mara K, Sullivan B. A simple bedside test to identify ulnar collateral flow. Ann Intern Med. 1995;123:637.
  8. Starnes SL, et al. Noninvasive evaluation of hand circulation before radial artery harvest for coronary artery bypass grafting. J Thorac Cardiovasc Surg. 1999;117:261–266.
  9. Cable DG, et al. The Allen test. Ann Thorac Surg. 1999;67:876–877.

With the recent practice of harvesting radial arteries for coronary artery bypass grafts, the literature has been reactivated on the test described by Edgar Allen in 1929 but subsequently modified in various ways and with adoption of technologies beyond the examiner's fingers. A variety of articles show that the classic 1929 Allen's test may have a high error rate, but other techniques with newer instrumentation and modifications are effective. Our question does not specify the exact nature of the test employed (that is, we do not say "Allen's test"). Also, from a medicolegal perspective, we probably would not want to eliminate this existing field question, only to have a patient lose a hand down the road and the hospital state that it used to test for collateral circulation but stopped doing so when the CAP removed the item from the checklist.

However, since all of these tests are somewhat controversial in the literature, we have added the aforementioned note. That permits opting out of the test under defined clinical circumstances, which should be documented. From the CAP's perspective, there is no specific reason for documenting each time that a collateral circulation test is performed if that is a routine part of the arterial blood gas protocol; however, some institutions have that as a local requirement.