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Avoid Sample Rejections

Avoid Sample Rejections Due to Hemolysis


Hemolysis involves breakage of red blood cell (RBC) membrane which causes the release of hemoglobin and other internal components into the surrounding fluid (Plasma).

  • Hemolysis is a widely documented issue for blood samples collected in emergency departments and other high risk departments where nurses are obtaining specimens while managing multiple aspects of patient care
  • Hemolysis is a serious issue because it may compromise the laboratory’s test parameters and lead to erroneous result reports


Factors that may contribute to hemolysis of blood samples can range from physiologic characteristics of the patient (e.g., dehydration) to the method and/or equipment used during phlebotomy, such as:

  • not allowing the alcohol to dry when prepping the skin
  • intravenous catheter gauge that is too big or small o pulling a syringe plunger back too fast and/or forcefully
  • forcefully expelling the blood from a syringe into the blood tube
  • vigorously shaking the tubes
  • under filled tubes, causing improper blood-to-additive ratios
  • increased tourniquet time and manipulation of the extremity


Patient test results can be affected by hemolysis and this is especially true in chemistry. The amount of result interference will depend on the degree of hemolysis and on the specific test methods being used. Accurate patient test results require accurate specimen collection and handling.

Accurate specimen collection techniques:

  • Ensure all blood collection assemblies are fitted securely to avoid frothing
  • Choose a needle gauge size based on the patient’s physical characteristics and amount of blood to be drawn. Most commonly used sizes are 19 through 23 gauge.
  • Release tourniquet after no more than one minute
  • Avoid fist clenching (it is associated with hyperkalemia)
  • After cleansing the skin allow the venipuncture site to air dry without touching it
  • Avoid drawing syringe plunger back too forcefully, this creates turbulence and physical forces that can rupture RBCs
  • Avoid pushing plunger when transferring to a tube
  • Gently invert the blood collection tube and mix additive specimens thoroughly

Medical Technologists in the lab are advocating for safe patient care when they reject a hemolyzed specimen. Nurses should recognize that accurate patient test results require accurate specimen collection and handling. Experience and proper technique are key to preventing hemolysis.


    1. Arzoumanian, L. Tech Talk 2003; 2(2)
    2. Dugan, L et al. J Emerg Nursing 2005; 31(4)
    3. Bush, V. et al. Lab Notes 2003;13(1)
    4. Bailey IR et al. Annals of Clinical Biochemistry 2008; 45(Pt 3)
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