Question 75

Moving the tubes in a figure eight motion 4 to 8 times after collection is the method a phlebotomist should use to invert tubes to prevent clotting.

Inverting tubes using a figure eight motion helps ensure that the anticoagulant is properly mixed with the blood specimen, which is crucial in preventing clotting.

A) Shaking the tubes 4 to 8 times after collection

Shaking the tubes can create bubbles and may cause hemolysis of the sample, which can affect test results. This method is not recommended as it does not provide the gentle mixing needed to uniformly distribute the anticoagulant.

B) Moving the tubes in a figure eight motion 4 to 8 times after collection

This method is effective because it allows for thorough mixing of the blood with the anticoagulant while minimizing turbulence. The figure eight motion is gentle and helps to prevent clot formation, making it the correct method for inverting tubes.

C) Rolling the tubes between the palms of the hands 4 to 8 times after collection

While rolling may mix the contents, it is less effective than the figure eight motion because it does not ensure that the anticoagulant is evenly distributed throughout the blood. This method could also potentially lead to uneven mixing.

D) Passing the tubes from hand to hand 4 to 8 times after collection

Passing tubes from hand to hand may not adequately mix the blood with the anticoagulant, as it does not involve a consistent motion that promotes thorough mixing. This method is less effective and could increase the risk of clotting.

Conclusion

The figure eight motion is the preferred technique for inverting tubes as it effectively prevents clotting by ensuring adequate mixing of the anticoagulant with the blood sample. Other methods, such as shaking or rolling, are either ineffective or may compromise the sample quality, making them unsuitable for this purpose.