3.6 Phlebotomy
Key Takeaways
- The order of draw for vacuum tubes is: blood cultures (yellow), light blue (coagulation), red (no additive), gold/SST (serum separator), green (heparin), lavender/purple (EDTA), gray (oxalate/fluoride)
- The median cubital vein in the antecubital fossa is the preferred venipuncture site; the cephalic and basilic veins are alternatives
- A tourniquet should not remain on the arm for more than 1 minute to prevent hemoconcentration and inaccurate results
- Venipuncture complications include hematoma, nerve injury, syncope (fainting), infection, and hemolysis of the specimen
- Capillary puncture (dermal puncture) is used for infants, elderly patients with fragile veins, and when only small amounts of blood are needed
- Specimens must be labeled at the bedside/chairside immediately after collection with patient name, DOB, date/time, collector initials, and test ordered
Last updated: March 2026
Phlebotomy
Phlebotomy (blood collection) is a core clinical skill for medical assistants. The CCMA exam tests your knowledge of venipuncture technique, order of draw, site selection, specimen handling, and complication management.
Venipuncture Equipment
| Equipment | Purpose |
|---|---|
| Evacuated tubes (Vacutainer) | Collect blood into color-coded tubes with specific additives |
| Multi-sample needle | Allows collection of multiple tubes from one venipuncture |
| Tube holder/adapter | Holds the needle and tube during collection |
| Tourniquet | Restricts venous blood flow to engorge veins |
| Alcohol prep pad | Cleans the puncture site (70% isopropyl alcohol) |
| Gauze pads | Apply pressure after needle removal |
| Bandage/tape | Cover the puncture site post-procedure |
| Needle disposal | Sharps container for used needles |
| Butterfly (winged infusion) set | Used for difficult veins, hand veins, and pediatric patients |
| Syringe | Alternative for fragile veins; prevents vacuum from collapsing the vein |
Order of Draw (Evacuated Tube System)
The order of draw prevents cross-contamination of additives between tubes:
| Order | Tube Color | Additive | Common Tests |
|---|---|---|---|
| 1 | Yellow (SPS) or blood culture bottles | SPS or none | Blood cultures (aerobic first, then anaerobic) |
| 2 | Light blue | Sodium citrate | Coagulation studies (PT/INR, PTT, D-dimer) |
| 3 | Red | None (no additive) | Blood bank, serology, some chemistry |
| 4 | Gold/red-gray (SST) | Clot activator + gel separator | Chemistry panels, thyroid, lipids |
| 5 | Green | Lithium heparin or sodium heparin | STAT chemistry, ammonia |
| 6 | Lavender/purple (EDTA) | EDTA | CBC, hemoglobin A1C, ESR, blood typing |
| 7 | Gray | Potassium oxalate + sodium fluoride | Glucose, blood alcohol |
Memory Aid for Order of Draw: "Stop Light Red, Go Low Gray" or "Boys Love Red Gold, Girls Love Gray"
- Blood cultures → Light blue → Red → Gold → Green → Lavender → Gray
Why order matters:
- Light blue tubes MUST be the first additive tube (or second if blood cultures are drawn) because citrate contamination from other tubes affects coagulation results
- EDTA contamination (lavender tube) can falsely elevate potassium levels if it gets into chemistry tubes
Venipuncture Site Selection
Preferred site: Median cubital vein — located in the antecubital fossa (inner elbow area)
- Largest, most stable vein
- Closest to the surface
- Least painful
- Least likely to cause complications
Alternative sites (if median cubital is unavailable):
- Cephalic vein — lateral (thumb) side of the antecubital fossa
- Basilic vein — medial (pinky) side; closest to brachial artery and median nerve — higher risk of injury
Sites to AVOID:
- Arms with IV infusions (results will be diluted/contaminated)
- Arm on the side of a mastectomy (lymphedema risk)
- Scarred or burned areas
- Arms with AV fistulas or grafts (dialysis patients)
- Edematous (swollen) areas
- Areas with hematomas from previous attempts
Venipuncture Procedure
- Verify the order and identify the patient (two identifiers)
- Assemble equipment; check tube expiration dates
- Explain the procedure to the patient; obtain consent
- Position the patient's arm extended and supported, palm up
- Apply the tourniquet 3-4 inches above the intended puncture site
- Select the vein by palpation (feel for a spongy, bouncy vessel)
- Clean the site with 70% alcohol in a circular motion; allow to air dry
- Anchor the vein by pulling the skin taut below the puncture site
- Insert the needle at a 15-30 degree angle, bevel up
- Collect tubes in the correct order of draw; invert additive tubes gently
- Release the tourniquet BEFORE removing the needle (within 1 minute of application)
- Remove the needle; apply gauze with pressure
- Activate the needle safety device; dispose in sharps container
- Label tubes at the bedside/chairside immediately
- Apply bandage after bleeding stops (2-5 minutes of pressure)
Tourniquet Rules:
- Apply 3-4 inches above the site
- Do NOT leave on for more than 1 minute (causes hemoconcentration, falsely elevated results)
- Release the tourniquet BEFORE removing the needle to prevent hematoma
- If a vein is not found within 1 minute, release for 2 minutes before reapplying
Capillary (Dermal) Puncture
Used when venipuncture is not feasible or for small-volume tests:
Indications:
- Infants and neonates (heel stick)
- Elderly patients with fragile veins
- Patients with burns or severe scarring on arms
- When small blood volume is sufficient (glucose, hemoglobin)
- Home monitoring (e.g., glucose self-testing)
Puncture Sites:
- Adults/children: Lateral sides of fingertips (ring or middle finger preferred)
- Infants (<12 months): Lateral or medial plantar surface of the heel (NEVER the arch or center)
Capillary Puncture Order of Draw:
- EDTA tubes (lavender microcontainer) — to prevent platelet clumping
- Other additive tubes
- Non-additive tubes (red microcontainer)
Note: The order of draw for capillary puncture differs from venipuncture because EDTA tubes are collected FIRST.
Phlebotomy Complications
| Complication | Cause | Prevention/Response |
|---|---|---|
| Hematoma | Blood leaking into tissue around the vein | Apply firm pressure for 2-5 minutes; release tourniquet before removing needle |
| Syncope (fainting) | Vasovagal response | Observe patient for signs; lower head; have ammonia inhalant available |
| Nerve injury | Needle contacts a nerve | Immediately withdraw if patient reports sharp, shooting pain; do NOT probe |
| Hemolysis | RBCs rupture, releasing hemoglobin | Use correct gauge needle; avoid fist pumping; gently invert tubes |
| Hemoconcentration | Tourniquet left on too long (>1 min) | Release tourniquet within 1 minute |
| Infection | Non-sterile technique | Proper skin antisepsis; do not palpate after cleaning |
| Petechiae | Tourniquet too tight | Adjust tourniquet pressure |
| Collapsed vein | Too much vacuum (fragile vein) | Use butterfly or syringe technique for fragile veins |
If unsuccessful after 2 attempts: Stop and have another qualified phlebotomist try. Never make more than 2 attempts on one patient.
Test Your Knowledge
What is the CORRECT order of draw for evacuated tubes?
A
B
C
D
Test Your Knowledge
The PREFERRED vein for routine venipuncture is the:
A
B
C
D
Test Your Knowledge
How long can a tourniquet remain on the patient's arm during venipuncture?
A
B
C
D
Test Your Knowledge
When performing a capillary puncture on an infant, the correct site is the:
A
B
C
D
Test Your KnowledgeOrdering
Arrange the venipuncture steps in the correct order.
Arrange the items in the correct order
1
Apply tourniquet 3-4 inches above the site
2
Verify the order and identify the patient
3
Insert the needle at 15-30 degrees, bevel up
4
Clean the site with alcohol and allow to air dry
5
Release the tourniquet before removing the needle
6
Label tubes at the bedside immediately