NCMA Phlebotomy Procedures and Order of Draw 2

Question 1

What is the correct order of draw when collecting multiple tubes during a single venipuncture?

Accepted Answer

Blood culture bottles → Yellow SPS → Light blue (sodium citrate) → Red/gold SST → Green (heparin) → Lavender (EDTA) → Gray (fluoride)

Answer

CLSI-recommended order of draw prevents additive carryover between tubes: blood cultures first (sterile technique), then light blue (citrate, critical to fill exactly), then additives in sequence — SST, heparin, EDTA, fluoride.

Question 2

What is the purpose of inverting blood collection tubes immediately after drawing?

Accepted Answer

To mix the blood with the tube's additive (anticoagulant or clot activator) to achieve the intended preservation or anticoagulation effect

Answer

Inverting collection tubes gently (3–8 times depending on the additive) mixes blood with the additive — EDTA, heparin, sodium citrate, or clot activator — ensuring proper anticoagulation or activation and preventing clotting in anticoagulant tubes or incomplete clot formation in SST tubes.

Question 3

Where is the antecubital fossa located, and why is it the preferred venipuncture site?

Accepted Answer

The inner surface of the elbow joint; preferred because it has large, accessible veins (cephalic, basilic, median cubital) with minimal underlying nerve and artery risk

Answer

The antecubital fossa (AC fossa) is the triangular area on the anterior (inner) surface of the elbow; it is the primary venipuncture site because the median cubital, cephalic, and basilic veins are superficial, large, and anchored, making them accessible and stable for needle insertion.

Question 4

What is the purpose of releasing the tourniquet before withdrawing the needle during venipuncture?

Accepted Answer

To restore normal blood flow and prevent hematoma formation and excessive bleeding at the puncture site upon needle removal

Answer

Releasing the tourniquet before withdrawing the needle restores normal venous pressure; removing the needle while the tourniquet is still applied causes increased venous back-pressure that promotes hematoma formation (blood leaking into surrounding tissue).

Question 5

What is the maximum recommended time a tourniquet should remain applied during venipuncture?

Accepted Answer

No more than 1 minute (60 seconds)

Answer

CLSI guidelines recommend tourniquet application not exceed 1 minute to prevent stasis and hemoconcentration, which falsely elevate protein, potassium, calcium, hemoglobin, and hematocrit levels.

NCMA - National Certified Medical Assistant Practice Test

NCMA - National Certified Medical Assistant Practice Test

NCMA Phlebotomy Procedures and Order of Draw 2