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Quick Question: Blood Collection

Here is a summary of our Feb-Apr, 2011 Quick Question:

What is your most frequent specimen collection error?

a. Short draw: 82 (49%)
b. Patient misidentified: 5 (3%)
c. Wrong test orders: 10 (6%)
d. Specimen clotted: 17 (10%)
e. Specimen hemolyzed: 54 (32%)

These results are self-explanatory except perhaps “patient misidentified,” which was reported less often than published studies would contend, which is somewhere around 1–3%. This probably means our respondents are doing a good job of communicating with their blood collectors about specimen ID. I’m sure it does not mean that we are missing some incorrectly labeled specimens.

The issue of underfilled tubes (short draw) is a little larger than I expected. This is addressed in Dennis Ernst’s. Blood Specimen Collections FAQs, Center for Phlebotomy Education, Inc, 208 on pages 348–349, a book I recommend for its authoritative practical tips. Does anyone have a scheme that motivates their blood collectors to fill the collection tubes?

On the subject of hemolysis, I heard Paul Epner speak in Knoxville, TN last month about the CDC/Batelle Memorial Institute Laboratory Medicine Best Practices project, which has published some data on the causes of hemolysis. Hemolysis seems to be often attributed to line draw techniques, and I invite anyone who has been successful at reducing the number of hemolyzed specimens to provide us with your approach.

Comments (2)
Dennis Ernst
May 25, 2011 2:35pm

There have been quite a lot of studies done on hemolysis. Th
There have been quite a lot of studies done on hemolysis. The most common cause is usually draws during IV starts. Some studies show 25% of samples drawn this way will be hemolyzed. Teflon and vialon catheters are the worst with 42% and 55% hemolysis rates respectively. Aside from vascular access devices, the common causes are vigorous mixing, temperature extremes, prolonged tourniquet application (beyond one minute), needle occlusion, forcefully evacuating a syringe into a tube, forcefully pulling on the plunger of a syringe, and using 25-gauge needles. Unless the patient has a disorder that leads to red cell fragility, all hemolysis is preventable by technique, which goes back to education. Do a search for “hemolysis” at and many articles on hemolysis are readily accessible.

Dennis Ernst, Center For Phlebotomy Education
May 4, 2011 2:03pm

My recommendation to avoid underfilling is to make sure one
My recommendation to avoid underfilling is to make sure one has a wide variety of lesser-volume tubes within reach. When the draw doesn’t produce the volume of blood required to fill an adult tube, then pediatric-sized tubes might be filled to full capacity. Without smaller tubes available, people are tempted to combine the contents of tubes, which is problematic. Even if two partially filled tubes have the same additive, the final concentration will be much higher than it should be and could alter test results.

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