Order of Draw Chapter 7 Flashcards
Order of Draw (color stoppers in order)
- Blood culture or yellow
- Light blue
- Red
- Gold or tiger top
- Light green
- Green
- Lavender
- Grey
Why is the blood culture tube first?
Minimizes the chance of microbial contamination.
What does SST stand for?
Serum separator tube
-red/grey molted (tiger top) or gold tube
What does PST stand for?
Plasma separator tube
-light green/molted grey/green tube
What does EDTA stand for?
Ethylenediaminetetraacetic acid
-lavender tube, pink, tan, some in gray
What does CPD stand for?
Citrate phosphate dextrose
What does SPS stand for?
Sodium polyanethol sulfonate
What does RST stand for?
Rapid serum tube
-Orange tube
What does PPT stand for?
Plasma preparation tube
-white/pearl colored tube
Why is the light blue tube (coagulation tube) second in the order of draw - after BC tubes?
The first additive tube in the order of draw because all other additive tubes affect coagulation tests
Why is the red (plastic) tube and SSTs (red/gray (tiger top) and gold) third and fourth in the order of draw- after the coagulation tubes and before the anticoagulant tubes?
Filled after coagulation tube because silica particles activate clotting and affect coagulation tests (carryover of silica into subsequent tubes can be overridden by anticoagulant in them)
Why are the heparin tubes and heparin PSTs fifth and sixth in the order of draw - after the serum separator tubes and before the other anticoagulant tubes?
Heparin affects coagulation tests and interferes in collection of serum specimens; it causes the least interference in tests other than coagulation tests. It occurs naturally in blood
Why are EDTA tubes (lavender) and EDTA PPTs (pearl/white) used second to last in the order of draw?
Responsible for more carryover problems than any other additives. Elevates Na (sodium) and K (potassium) levels, chelates (bonding of ions and molecules to metal ions) and decreases calcium and iron levels, elevates PT and PTT results.
Why are oxalate/fluoride tubes (gray) used last in the order of draw?
Sodium fluoride and potassium oxalate affect sodium and potassium levels. Filled after hematology tubes because oxalate damages cell membranes and causes abnormal RBC morphology. Oxalate interferes in enzyme reactions.
