2.2 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.

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Fasting Requirements

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

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

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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)

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Medication Considerations

Certain medications affect blood collection and specimen integrity:

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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

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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

Effects of Exercise

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

Effects of Smoking

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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

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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

Special Situations in Patient Identification

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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.

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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.

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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

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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.