Garbage In; Garbage Out: Part VI

Over the last few months, Phlebotomy Today-STAT! has been exploring the many ways those who draw and process specimens can unknowingly alter test results. Last month we discussed how clots in anticoagulant tubes can wreak havoc on specimens, test results and instrumentation as well as how underfilling tubes and blood culture bottles cheat the patient out of accurate results. (To access this and other archived issues, visit www.phlebotomy.com/PTSTAT.html) This month we will continue with delays in processing.

Serum/cell contact
From the moment the blood enters the tube, its cellular and chemical components are subject to fluctuations due to the exchange of analytes between red and white blood cells and the serum or plasma they are suspended in. Those with specimen collection responsibilities who don’t take this dramatic potential into consideration when they transport and handle specimens risk being party to medical mismanagement.
       Allow a blood specimen to sit with the serum/plasma remaining in contact with the cells longer than two hours and you allow the specimen’s chemical composition to change significantly. Most texts and standards are in agreement that you should remove serum or plasma from the cells within two hours of collection in order to preserve the concentration of many analytes to be tested by the laboratory’s chemistry department.
       But in the case of red-top tubes, make sure complete clotting occurs first, a process that can take up to 30 minutes even with a clot activator tube. (Tubes with anticoagulants can be centrifuged immediately.) Centrifugation forces all the cellular components of the blood to the bottom of the tube with the cell-free liquid to be tested remaining at the top. If the tube does not contain a gel barrier, separating the serum or plasma from the cells can be done by removing the stopper, and transferring an aliquot to a transfer tube with a pipette.
       Most tubes destined for centrifugation now have a gel-type separator to facilitate processing. The gel is designed to position itself between the serum or plasma and the cells during centrifugation, negating the need to physically access the specimen. It serves as an effective barrier to prevent ions and compounds from changing in their concentration. However, not all gel tubes are created equal. The gel tubes of some manufacturers have storage limitations for certain therapeutic drugs. Therefore, it is prudent to verify the tube’s acceptability before collecting any therapeutic drug level into a gel-separator tube.

Green-top tubes
Whole blood specimens in green-top tubes (heparinized) are not to be chilled while awaiting transportation to the testing facility unless it is documented that immediate chilling is necessary to preserve values. In general, tubes anticoagulated with heparin for routine chemistry analysis should be handled with the same processing precautions red-top tubes require. Unless whole blood will be tested, separate the plasma from the cells as soon as possible and do not refrigerate before centrifugation. Green-top tubes that require immediate chilling (e.g., renin) should not be used for potassium testing since its concentration skyrockets in the plasma of refrigerated tubes whenever the cells remain in contact with the plasma.

Blue-top tubes
Some clotting factors in the blood deteriorate rapidly once collected. Because blue-top tubes (sodium citrate) are used to test for such factors, they should be processed as soon as possible. Even though a prothrombin time (PT) is stable in an uncentrifuged, unrefrigerated tube for up to 24 hours, an activated partial thromboplastin time (aPTT) deteriorates significantly after four hours regardless of the storage and/or transportation temperature. If testing is delayed beyond four hours, aPTT results will be unreliable unless the specimen is centrifuged and the plasma frozen.
      Because of this instability, aPTT and some factor assays not processed and tested within four hours of collection can present misleading information about the patient’s clotting ability and/or anticoagulant dosage. If coagulation tests are not performed with strict compliance with the limitations of time, the patient can be overmedicated, which risks hemorrhage.

Lavender-top tubes
Tubes collected for hematological studies (EDTA tubes for CBC, retic count, sedimentation rate, platelet count, etc.) may be transported to the laboratory testing area at room temperature. But specimens for sedimentation rates and reticulocyte counts should be refrigerated if testing is not anticipated to occur within four and six hours respectively. As with heparinized tubes, some analytes drawn in EDTA tubes are required to be immediately chilled. When collection requirements suggest immediate chilling, specimens should be transported on ice or in ice water promptly after collection and labeling.
      Adherence to basic specimen-handling guidelines is the only way to avoid becoming an expert in waste management: drawing and delivering to the laboratory specimens that are as good as garbage. Garbage in; garbage out.  Kick processing errors to the curb through proper training and continuing education.  Then the only delivery you’ll be making is that of a quality sample that accurately reflects the patient’s condition at the time of collection.

Gray-top tubes
Specimens to be tested for glucose are often drawn under circumstances that prevent centrifugation and separation within two hours of collection (e.g., long term care facilities, patient homes, etc.). When centrifugation is delayed, glycolysis threatens to consume the glucose within the tube, resulting in a falsely decreased result once the blood is tested. Gray-top (sodium fluoride) tubes prevent glycolysis, stabilizing glucose levels for as long as 1 week prior to centrifugation.
       Adherence to basic specimen-handling guidelines is the only way to avoid becoming an expert in waste management: drawing and delivering to the laboratory specimens that are as good as garbage. Garbage in; garbage out. Kick processing errors to the curb through proper training and continuing education. Then the only delivery you’ll be making is that of a quality sample that accurately reflects the patient’s condition at the time of collection.

Next month: Improper centrifugation

This Month in Phlebotomy Today

Here’s what subscribers to Phlebotomy Today, the Center for Phlebotomy Education’s paid-subscription newsletter currently in its 9^th year of publication, are reading about this month:

• The Pediatric Bandaging Dilemma: One Laboratory’s Solution
• Effects of Fist Pumping Underestimated
• Ask the Lab Guy: Answers to your questions on customer service:
• How do I handle patient's teasing?
  
• Phlebotomy in the News: a round-up of articles on phlebotomy and phlebotomists who made Internet headlines in October including these stories:
• Article Warns of Inappropriate Footwear in Healthcare
• Hospital Privacy Curtains Found to be Contaminated with Pathogens
• Hospital Staff Found Reusing Syringes on Multiple Patients
• More Facilities Eliminating Latex Gloves
• New Survey Rates Customer Satisfaction for 2400 Healthcare Facilities
• According to the Standards: Earlobes and Skin Punctures
• Tip of the Month: A Tangled Web
• CEU questions (institutional version only).

Buy this issue for only $9.95.

For subscription rates and to subscribe to Phlebotomy Today, visit www.phlebotomy.com/PhlebotomyToday.html. The current month’s issue will be emailed to you immediately upon subscribing.

Featured FAQ: Blood From Lines

Q: Our neurovascular intensive care nurses request phlebotomists learn to take blood from lines. What do you think of this idea? Have you ever heard of other hospitals actually doing this?

A: Unless you are in a state that regulates who can and can’t manage infusions, it’s not likely that there are any restrictions on training phlebotomists to do line draws. Generally, any employer can train any employee to perform the procedure as long as they provide adequate training. The onus is on the employer to develop a training regimen that protects the patient from complications. It’s rare in the industry for phlebotomists to be trained to draw blood from lines without nursing supervision.

Each month, PT--STAT! will publish one of the hundreds of phlebotomy FAQs in the growing database of questions and answers available in Phlebotomy Central, the members-only section of the Center for Phlebotomy Education's web site. For information on joining Phlebotomy Central, visit www.phlebotomy.com/PhlebotomyCentral.html.

Survey Says: Who’s Drawing ABGs?

For the last two months, visitors to phlebotomy.com were asked to complete an online survey as to which profession in their facility draws arterial blood gases (ABGs). As expected, the lion’s share is collected by respiratory therapists (RTs). In fact, 66% of those responding said RTs draw at least 90 percent of the ABGs at their hospital. Fifty-eight percent of respondents said RT draws them all. By contrast, 11 percent of those responding said phlebotomists draw 90 percent or more of their ABGs. Two percent of those responding indicated the laboratory testing personnel drew all the gases in their facilities, while only one facility reported that physicians draw all of their ABGs.

In this month’s survey, phlebotomy.com asks if your facility has a mechanism in place for monitoring the volume of blood drawn from newborns. Click here to participate in the survey.

ASCP, NCA Announce Unification

The American Society for Clinical Pathology and the National Credentialing Agency announced their agreement to unify as one certifying body. According to an article in Clinical Laboratory News, the merging bodies hope to simplify certification for employers, managers and applicants by their unification, which minimizes the number of competing agencies.

Although many details still need to be worked out, officials on both sides are continuing operations as normal. Those who are credentialed by either organization prior to the merger will be recognized by the unified organization. NCA posts regular statements on association activities at http://communicators.typepad.com/nca/.

What Would You Do?

Each month, What Would You Do? presents a different case study, then asks readers to contribute their ideas as to how each situation would best be handled. The following month, selected responses will be chosen by the editor and published (sender will be identified by first name and state only). The most accurate, well written response will receive a free "Accurate Results Begin With Me!^® t-shirt. The exercise will conclude with a review of the selected submissions and a discussion of the standards pertinent to the case study

As with past WWYD case studies, this one proved to be commonplace with our respondents. The most frequent suggestion, which came from seventy-two percent of those responding, was for frustrated applicants to volunteer, participate in an externship program, or work for reduced pay and benefits while they gain the valuable experience employers want. These are excellent ways for “green” applicants to get their foot in the door for a permanent position. Some (27%) suggested applying to a reference lab or physician’s office where the requirements may be less stringent, while others suggested applying at a blood donor center or plasma center.

But our favorite answer came from Elesha of South Dakota who told how she found her way out of this Catch 22:

“I recently went through this very scenario. My plan of action was to do a shadow program or do an internship! Instead I got hired at a hospital doing “fee biases” to gain more experience, which is working with out the benefits and less pay. After six months I finally get hired! So I would have to tell the next person straight out of school to try either of these great ideas!”

]Nothing works better than a tried and true solution. For her willingness to share her success so articulately, Elesha will receive an Accurate Results Begins With Me!™ t-shirt. Thanks, Elesha!