Key Takeaways

  • Verify fasting status for tests that require it — most fasting tests require 8-12 hours without food or drink (water is usually allowed)
  • Common fasting tests include glucose (fasting), lipid panel, and basic/comprehensive metabolic panels
  • Ask about latex allergy before applying a tourniquet — use non-latex alternatives (nitrile gloves, non-latex tourniquets) if positive
  • The preferred patient position for routine venipuncture is seated upright in a phlebotomy chair with the arm supported and slightly downward
  • Patients who have a history of syncope (fainting) should be positioned supine (lying down) during the draw
  • For pediatric patients, the parent may hold the child in their lap — a papoose board may be used for very young or uncooperative children
  • Verify the order of draw against the requisition form BEFORE beginning the collection to ensure proper tube selection
  • Ask about anticoagulant medications (warfarin, heparin, aspirin) as these patients may bleed longer and require extended pressure after the draw
Last updated: February 2026

Patient Preparation & Positioning

Proper patient preparation ensures specimen integrity and patient safety. Skipping preparation steps can lead to inaccurate test results, patient injury, and specimen rejection by the laboratory.


Fasting Requirements

Some laboratory tests require the patient to fast (abstain from food and caloric beverages) for a specified period before specimen collection:

TestFasting RequiredDuration
Fasting glucoseYes8-12 hours
Lipid panel (cholesterol, triglycerides, LDL, HDL)Yes (recommended)9-12 hours
Basic metabolic panel (BMP)Fasting preferred8-12 hours
Comprehensive metabolic panel (CMP)Fasting preferred8-12 hours
Iron studiesYes8-12 hours (best collected in morning)
Complete blood count (CBC)NoN/A
Coagulation tests (PT/INR, PTT)NoN/A
Thyroid panel (TSH, T3, T4)No (timing preferred — morning)N/A
Blood culturesNoN/A
Blood type and crossmatchNoN/A

Fasting Verification Protocol

  1. Ask the patient: "When was the last time you ate or drank anything other than water?"
  2. If the patient has NOT fasted appropriately:
    • Notify the ordering physician or nurse
    • Document that the specimen was collected as "non-fasting"
    • Some facilities require rescheduling the draw
  3. Water is generally allowed during fasting periods — black coffee and medications may also be permitted per physician order

Allergy Assessment

Before applying a tourniquet or selecting supplies, ask about allergies:

Latex Allergy

  • Ask every patient: "Do you have any allergies, particularly to latex?"
  • If positive: Use non-latex alternatives:
    • Nitrile gloves (instead of latex)
    • Non-latex tourniquet
    • Hypoallergenic tape or self-adherent bandage wraps
  • Signs of latex allergy: Redness, itching, hives, swelling at contact site; severe cases can cause anaphylaxis
  • Latex allergy is more common in: Healthcare workers (repeated exposure), patients with spina bifida, individuals with fruit allergies (banana, kiwi, avocado — cross-reactivity)

Other Allergies

  • Adhesive tape allergy: Use self-adherent wrap (Coban) instead of tape
  • Iodine/Betadine allergy: Use chlorhexidine or isopropyl alcohol for skin antisepsis (important for blood cultures)
  • Alcohol allergy: Use an alternative antiseptic (Betadine, chlorhexidine)

Medication Considerations

Certain medications affect blood collection and specimen integrity:

MedicationConsideration
Anticoagulants (warfarin, heparin, enoxaparin)Apply pressure for 3-5 minutes after draw; observe for prolonged bleeding
Aspirin / anti-platelet agentsMay increase bleeding time; apply firm pressure
IV fluidsDraw from the opposite arm to avoid contamination with IV fluid (hemodilution)
ChemotherapyPatients may be immunocompromised — strict infection control; veins may be fragile
MastectomyDo NOT draw from the arm on the side of mastectomy (lymphedema risk)

Patient Positioning

Proper positioning ensures patient comfort, safety, and optimal vein access.

Standard Seated Position (Routine Outpatient Draws)

  • Patient sits upright in a phlebotomy chair with an adjustable arm rest
  • Arm is extended, slightly downward, and fully supported
  • The arm should form a straight line from shoulder to wrist
  • Ensure the patient's feet are flat on the floor
  • The phlebotomy chair should have locking armrests to prevent the patient from falling if they faint

Supine Position (Hospital Inpatients / Syncope Risk)

  • Patient lies flat on their back in bed
  • Arm is extended at the side, supported by the bed or a pillow
  • Required for patients who:
    • Have a history of syncope (fainting) during blood draws
    • Are currently dizzy, lightheaded, or weak
    • Are sedated or unconscious
    • Request to lie down

Pediatric Positioning

  • Infants: May be positioned on a padded surface; parent or guardian assists with restraint
  • Toddlers and young children: Seated on the parent's lap with the parent holding the child's arm steady
  • Older children: May sit in a phlebotomy chair with parental support
  • Restraint devices (papoose boards) may be used for very young or uncooperative children, with parental consent

Positions to AVOID

  • Standing: Never draw blood from a standing patient — syncope risk
  • Arm above heart level: Causes venous pooling issues and slows blood flow
  • Arm bent sharply: May cause needle to penetrate through the vein

Dietary and Medication Effects on Laboratory Results

Phlebotomists must understand how dietary factors, medications, and patient conditions can affect specimen quality and test results:

Effects of Non-Fasting State

AnalyteEffect of Non-FastingImpact
TriglyceridesSignificantly elevated (most affected)Falsely high cardiovascular risk assessment
GlucoseElevatedMay falsely suggest diabetes
IronElevated after mealsIncorrect iron status
PhosphorusDecreased after high-carb mealIncorrect metabolic assessment
LipemiaTurbid (milky) serumMay interfere with many chemistry tests

Effects of Exercise

AnalyteEffect of Recent ExerciseDuration
CK (Creatine Kinase)Significantly elevated24-48 hours
LDHElevated24 hours
ASTMildly elevated24 hours
WBCTransiently elevated1-2 hours
Lactic acidSignificantly elevated1-2 hours

Clinical Tip: Patients should avoid strenuous exercise for 24 hours before certain tests (CK, aldolase, myoglobin) for the most accurate results.

Effects of Stress and Anxiety

AnalyteEffectMechanism
CortisolElevatedStress hormone response
GlucoseElevatedStress-induced glycogenolysis
WBCElevatedCatecholamine release
IronDecreasedAcute phase response

Effects of Smoking

AnalyteEffect
WBCChronically elevated
HemoglobinElevated (compensatory response to CO)
CarboxyhemoglobinElevated
CortisolElevated

Special Patient Situations

Patients Receiving IV Therapy

  • NEVER draw from the same arm as an active IV line
  • If you must draw from an arm with an IV (no other option):
    1. Ask the nurse to stop the IV for at least 2 minutes
    2. Apply the tourniquet below the IV site
    3. Draw from a vein distal to (farther from the heart than) the IV site
    4. Label the specimen as "drawn below IV site" and note the IV fluid
  • Preferred approach: Always draw from the opposite arm

Patients on Dialysis

  • NEVER draw from an AV fistula or graft without specific physician authorization
  • The fistula/graft arm is reserved for dialysis access
  • Draw from the opposite arm
  • If both arms have fistulas/grafts, obtain physician orders for an alternative site

Patients with Edema

  • Avoid edematous (swollen) areas — tissue fluid can contaminate the specimen
  • Apply tourniquet above the edema if possible
  • Alternative sites may be needed

Pre-Collection Verification Checklist

Before beginning any blood draw, verify:

  • Two patient identifiers confirmed
  • Lab requisition reviewed — correct patient, correct tests
  • Fasting status verified (if applicable)
  • Allergies assessed (latex, adhesive, antiseptic)
  • Medications noted (anticoagulants, IV fluids, mastectomy history)
  • Patient positioned correctly (seated or supine)
  • Supplies selected — correct tubes (order of draw), needle gauge, tourniquet
  • Informed consent obtained
Test Your Knowledge

A patient scheduled for a fasting glucose test reports they had coffee with cream 2 hours ago. What should the phlebotomist do?

A
B
C
D
Test Your Knowledge

A patient reports a latex allergy. Which of the following should the phlebotomist use?

A
B
C
D
Test Your Knowledge

Which patient should be positioned SUPINE (lying down) for a blood draw?

A
B
C
D
Test Your KnowledgeMulti-Select

Which of the following tests typically require the patient to fast for 8-12 hours? (Select all that apply)

Select all that apply

Fasting glucose
Complete blood count (CBC)
Lipid panel (cholesterol, triglycerides)
Blood cultures
Iron studies
Coagulation tests (PT/INR)
Test Your Knowledge

A patient has had a mastectomy on their left side. Where should the phlebotomist draw blood?

A
B
C
D
Test Your KnowledgeOrdering

Arrange the pre-collection verification steps in the correct order:

Arrange the items in the correct order

1
Select supplies and correct tubes
2
Verify two patient identifiers
3
Obtain informed consent
4
Check fasting status and allergies
5
Position the patient correctly
Test Your KnowledgeFill in the Blank

Blood should NEVER be drawn from an arm with an IV line running. Instead, the phlebotomist should draw from the _____ arm.

Type your answer below

Test Your Knowledge

A patient on warfarin (blood thinner) has blood drawn. After the draw, the phlebotomist should:

A
B
C
D
Test Your Knowledge

Which of the following is TRUE about the effects of prolonged tourniquet application on test results?

A
B
C
D
Test Your Knowledge

Latex allergy cross-reactivity may occur in patients who also have allergies to:

A
B
C
D
Test Your KnowledgeMatching

Match each type of consent to its description:

Match each item on the left with the correct item on the right

1
Expressed consent
2
Implied consent
3
Informed consent
4
Refusal
Test Your Knowledge

Which of the following practices violates HIPAA patient privacy regulations?

A
B
C
D
Test Your Knowledge

A phlebotomist needs to draw blood from a patient who is combative and attempting to hit the phlebotomist. What is the BEST action?

A
B
C
D
Test Your Knowledge

A patient scheduled for a lipid panel ate breakfast 4 hours ago. The phlebotomist should:

A
B
C
D
Test Your KnowledgeMulti-Select

Which of the following are TRUE about drawing blood from a patient receiving IV therapy? (Select all that apply)

Select all that apply

Draw from the opposite arm whenever possible
If you must draw from the IV arm, ask the nurse to stop the IV for 2 minutes first
It is acceptable to draw from directly above the IV site
Draw from a vein distal to (farther from the heart than) the IV site
Label the specimen noting it was drawn from the IV arm
Drawing near an IV can cause hemodilution of the specimen
Test Your Knowledge

A phlebotomist preparing to draw blood from an elderly patient notices the patient's veins appear thin and fragile. Which collection method would be MOST appropriate?

A
B
C
D
Test Your Knowledge

The phlebotomist should ask the patient to make a gentle fist during venipuncture. Why should the patient NOT pump their fist repeatedly?

A
B
C
D
Test Your Knowledge

When verifying a patient's identity, which type of identifier is NOT acceptable?

A
B
C
D
Test Your Knowledge

A patient who is NPO (nothing by mouth) is allowed to have which of the following before a fasting blood draw?

A
B
C
D

Special Situations in Patient Identification


Emergency / Unknown Patients

When a patient cannot be identified (unconscious, unresponsive, no ID band):

  1. Do NOT draw blood until a temporary identification system is established
  2. The facility's emergency ID protocol assigns a temporary identifier (e.g., "Trauma Male 1" or a numeric code)
  3. A temporary armband with the assigned identifier must be placed on the patient
  4. All specimens must be labeled with this temporary identifier
  5. Once the patient is identified, the temporary ID is linked to the permanent medical record

Critical Rule: NEVER draw blood from a patient without an identification band, even if you recognize the patient. Identification bands must be physically attached to the patient.


Discrepancy Resolution

If any information on the ID band does NOT match the requisition:

  • STOP — do NOT proceed with the blood draw
  • Notify the nurse or charge nurse to resolve the discrepancy
  • A new requisition or corrected ID band must be obtained
  • Document the discrepancy and the resolution

Common discrepancies include: misspelled names, transposed DOB digits, old ID bands from previous admissions, and missing ID bands.


Outpatient / Ambulatory Settings

In outpatient settings (clinics, physician offices, reference labs):

  • Patients may not have wristbands — use photo ID (driver's license, passport) plus verbal verification
  • Always verify the identity against the requisition form or electronic order
  • Ask the patient to spell their name and state their DOB
  • For repeat patients, never assume identity based on recognition alone

Refusal to Consent

If a patient refuses the blood draw:

  1. Explain the importance of the test calmly and professionally
  2. Ask if there is a specific concern you can address (fear of needles, religious beliefs, etc.)
  3. If the patient still refuses, respect their decision — patient autonomy is paramount
  4. Document the refusal in the patient's record
  5. Notify the ordering physician of the refusal
  6. Never attempt to draw blood from a patient who has refused

Legal Note: Drawing blood from a patient who has refused constitutes assault and battery. Even unconscious patients are assumed to have given implied consent for emergency situations only.

Test Your KnowledgeOrdering

Arrange the correct sequence when a patient's identification band does not match the requisition:

Arrange the items in the correct order

1
Identify the discrepancy between the ID band and the requisition
2
Stop — do NOT proceed with the blood draw
3
Notify the nurse or charge nurse of the discrepancy
4
Wait for a corrected ID band or new requisition to be issued
5
Verify the corrected information matches before proceeding with the draw
Test Your KnowledgeFill in the Blank

In an emergency when a patient cannot be identified, a ____ identification system is used to assign a temporary number or name until the patient is properly identified.

Type your answer below

Test Your Knowledge

A phlebotomist arrives to draw blood and notices the patient does not have an identification band. The nurse says, "That's Mr. Johnson in bed 2, I know him well." What should the phlebotomist do?

A
B
C
D
Test Your KnowledgeMatching

Match each special patient situation with the correct phlebotomy approach:

Match each item on the left with the correct item on the right

1
Patient on IV fluids in the right arm
2
Patient with a mastectomy on the left side
3
Patient receiving dialysis via AV fistula in left arm
4
Patient with edema in both arms