Section III: Phlebotomy & Point-of-Care Testing

• Order of Draw (Color Tubes, Additives, Tests) • Venipuncture Step-by-Step • Capillary Collection Guidelines • CLIA-Waived Tests List • Chain of Custody Procedures

Yellow (SPS)

Sodium polyanethol sulfonate

Blood cultures

Light Blue

Sodium citrate

PT, PTT, INR

Red

No additive or clot activator

Drug levels, serum

Gold/Tiger (SST)

Gel separator & clot activator

CMP, BMP, Lipids

Green

Heparin

Electrolytes, troponin

Lavender/Purple

EDTA
CBC, HgbA1c, ESR

Gray

Potassium oxalate & sodium fluoride

Glucose, GTT, lactic acid

Vacutainer (Straight Needle)

21G, Standard venipuncture, Most common

Syringe

21– 23G, Fragile veins or small draws, Requires transfer

Butterfly (Winged Set)

23– 25G, Small rolling veins, Used for peds or elderly

Capillary Puncture (Fingerstick/Heelstick)

Lancet, Small blood volume, Heel used for infants <12 months

Median Cubital Vein

First choice (center of antecubital area)

Cephalic Vein

Lateral side; good for obese patients

Basilic Vein

Medial side; last resort due to artery proximity

AVOID

• Veins near IVs

• Same side as a mastectomy

• Bruised, burned, or scarred areas

Tourniquet Rules

• Place 3–4 inches above puncture site

• Do NOT leave on >1 minute

• Causes hemoconcentration if left too long

• Remove before needle is withdrawn I

• f it’s been on too long → remove, wait 2 minutes, then reapply

Hemolysis

• What it is: Destruction of RBCs

• Causes: Too small a needle (e.g., 25G), Shaking tubes instead of inverting, Not letting alcohol dry, Pulling plunger too fast

• Appearance: Pink/red serum → sample must be rejected

Hematoma

• What it is: Blood leak under skin (bruise)

• Causes: Missed vein or needle pushed through, Not enough pressure after draw

• Prevention: Anchor vein properly, Use correct angle (15–30°), Apply pressure for at least 1 minute

Hemoconcentration

• What it is: Excessive concentration of cells/solutes in the blood

• Main Cause: Tourniquet on too long → falsely elevated labs (glucose, K⁺, protein)

Capillary Collection

>1 year (child/adult) Fingerstick (3rd or 4th finger, side of tip)

<1 year (infant) Lateral heel

*Wipe away first drop, it may contain tissue fluid and skew results.

CLIA Waived Tests (Point-of-Care)

Urinalysis, Glucose, Pregnancy tests, rapid strep/flu tests, hemoglobin

Urinalysis (dipstick)

Urine, Check pH, glucose, protein, etc.

Glucose

Capillary blood, Fingerstick, glucometer

Pregnancy Test

Urine, hCG detection

Rapid strep/flu test

Swab Quick pathogen ID

Hemoglobin

Capillary, Hemocue device

Chain of Custody

Used in legal cases: drug testing, paternity, forensic testing.

Steps:

• Label at bedside

• Seal and secure specimen

• Document every handoff

• Signature required at each stage

Any break in the chain = test is invalid

BIG Mistakes

• Shaking tubes → Hemolysis

• Leaving tourniquet >1 minute → Hemoconcentration

• Incorrect tube order → Contaminated sample

• Not labeling in front of patient → Rejection

• Improper pressure after draw → Hematoma

• Using alcohol for blood alcohol test → Invalid result

Blood Glucose

• Normal (fasting): 70–99 mg/dL

• Random: <140 mg/dL

• Pre-diabetes (fasting): 100–125 mg/dL

• Diabetes (fasting): ≥126 mg/dL

If glucose is high → retest, report to provider

Hemoglobin (Hgb) Ranges

Normal (Adult Female): 12–16 g/dL

Normal (Adult Male): 13–18 g/dL

Low Hgb = Anemia

Urine hCG (Pregnancy Test)

• Positive = Detected hCG in urine

• Best sample: First-morning urine

Read results within time window to avoid false positives/evaporation lines

Rapid Strep Test

• Uses throat swab

• Detects group A streptococcus

• Positive = notify provider, initiate antibiotics

Rapid Influenza A/B Test

• Uses nasal or nasopharyngeal swab

• Detects influenza viral antigens

• Helps provider start antivirals quickly

Venipuncture Procedure

1. Verify order & ID patient (name + DOB)

2. Wash hands & apply gloves

3. Gather supplies → tourniquet, tubes, needle, gauze, etc.

4. Apply tourniquet (max 1 min)

5. Palpate, then cleanse site (let dry!)

6. Insert needle → collect in proper order

7. Release tourniquet → withdraw needle

8. Apply gauze with pressure

9. Invert tubes gently

10. Label tubes in front of patient

11. Dispose of sharps