Phlebotomy Procedures and Order of Draw Flashcards
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Read the first 6 Phlebotomy Procedures and Order of Draw flashcards as text
What is the correct order of draw when collecting multiple tubes during a single venipuncture?
Answer: Blood culture bottles → Yellow SPS → Light blue (sodium citrate) → Red/gold SST → Green (heparin) → Lavender (EDTA) → Gray (fluoride)
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.
What is the purpose of inverting blood collection tubes immediately after drawing?
Answer: To mix the blood with the tube's additive (anticoagulant or clot activator) to achieve the intended preservation or anticoagulation effect
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.
Where is the antecubital fossa located, and why is it the preferred venipuncture site?
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
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.
What is the purpose of releasing the tourniquet before withdrawing the needle during venipuncture?
Answer: To restore normal blood flow and prevent hematoma formation and excessive bleeding at the puncture site upon needle removal
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).
What is the maximum recommended time a tourniquet should remain applied during venipuncture?
Answer: No more than 1 minute (60 seconds)
CLSI guidelines recommend tourniquet application not exceed 1 minute to prevent stasis and hemoconcentration, which falsely elevate protein, potassium, calcium, hemoglobin, and hematocrit levels.
A medical assistant accidentally punctures a patient's brachial artery during a venipuncture attempt. What is the IMMEDIATE appropriate action?
Answer: Remove the needle immediately, apply firm continuous pressure for at least 5 minutes, and notify the provider
Arterial puncture is recognized by bright red, pulsatile blood flow; the needle must be removed immediately and firm, sustained pressure (5–10 minutes minimum) applied directly over the site to achieve hemostasis and prevent significant hematoma or compartment syndrome.