4 Order of Draw and Tube Selection Free Online FlashCards

What is the standard venous order of draw?

Collect in this order: cultures or sterile specimens, citrate, serum, heparin, EDTA, then glycolysis-inhibitor tubes.

What additive and common tests are associated with light-blue tubes?

Light-blue tubes typically contain sodium citrate and are used for coagulation tests such as PT/INR and aPTT.

Why must a light-blue tube be filled to its marked volume?

Fill it to the marked volume to maintain the required blood-to-citrate ratio; underfilling can distort results.

How is serum prepared from a blood specimen?

Allow the blood to clot, then centrifuge as instructed to separate the serum from the cells.

What happens to a whole-blood specimen for a test that requires blood cells?

Whole blood remains uncentrifuged when the test requires blood cells, as many CBCs do.

Why should tube selection not rely on color alone?

Color conventions are only examples; verify the tube label and manufacturer information because contents can vary.

When should a clot-activator serum tube precede a coagulation tube?

A clot-activator serum tube should not precede a coagulation tube unless the laboratory specifically directs otherwise.

What can cause the first light-blue tube in a winged collection to be underfilled?

Air in the tubing can underfill the first light-blue tube. Follow laboratory procedure for using a discard tube when needed.

How should additive tubes be mixed after collection?

Invert additive tubes gently the number of times specified by the manufacturer or laboratory; do not shake them.

What can improper mixing do to a blood specimen?

Vigorous shaking can damage blood cells, while failing to mix anticoagulant tubes can allow clots to form.

When should collection tubes be labeled?

Label each tube at the patient’s side immediately after collection; never prelabel tubes or leave them unlabeled for later identification.

How should blood be transferred from a syringe into collection tubes?

Use an approved safety transfer device. Do not force blood from a syringe or push its plunger into a tube, which can cause hemolysis and a needlestick hazard.