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
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:
| Test | Fasting Required | Duration |
|---|---|---|
| Fasting glucose | Yes | 8-12 hours |
| Lipid panel (cholesterol, triglycerides, LDL, HDL) | Yes (recommended) | 9-12 hours |
| Basic metabolic panel (BMP) | Fasting preferred | 8-12 hours |
| Comprehensive metabolic panel (CMP) | Fasting preferred | 8-12 hours |
| Iron studies | Yes | 8-12 hours (best collected in morning) |
| Complete blood count (CBC) | No | N/A |
| Coagulation tests (PT/INR, PTT) | No | N/A |
| Thyroid panel (TSH, T3, T4) | No (timing preferred — morning) | N/A |
| Blood cultures | No | N/A |
| Blood type and crossmatch | No | N/A |
Fasting Verification Protocol
- Ask the patient: "When was the last time you ate or drank anything other than water?"
- 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
- 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:
| Medication | Consideration |
|---|---|
| Anticoagulants (warfarin, heparin, enoxaparin) | Apply pressure for 3-5 minutes after draw; observe for prolonged bleeding |
| Aspirin / anti-platelet agents | May increase bleeding time; apply firm pressure |
| IV fluids | Draw from the opposite arm to avoid contamination with IV fluid (hemodilution) |
| Chemotherapy | Patients may be immunocompromised — strict infection control; veins may be fragile |
| Mastectomy | Do 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
| Analyte | Effect of Non-Fasting | Impact |
|---|---|---|
| Triglycerides | Significantly elevated (most affected) | Falsely high cardiovascular risk assessment |
| Glucose | Elevated | May falsely suggest diabetes |
| Iron | Elevated after meals | Incorrect iron status |
| Phosphorus | Decreased after high-carb meal | Incorrect metabolic assessment |
| Lipemia | Turbid (milky) serum | May interfere with many chemistry tests |
Effects of Exercise
| Analyte | Effect of Recent Exercise | Duration |
|---|---|---|
| CK (Creatine Kinase) | Significantly elevated | 24-48 hours |
| LDH | Elevated | 24 hours |
| AST | Mildly elevated | 24 hours |
| WBC | Transiently elevated | 1-2 hours |
| Lactic acid | Significantly elevated | 1-2 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
| Analyte | Effect | Mechanism |
|---|---|---|
| Cortisol | Elevated | Stress hormone response |
| Glucose | Elevated | Stress-induced glycogenolysis |
| WBC | Elevated | Catecholamine release |
| Iron | Decreased | Acute phase response |
Effects of Smoking
| Analyte | Effect |
|---|---|
| WBC | Chronically elevated |
| Hemoglobin | Elevated (compensatory response to CO) |
| Carboxyhemoglobin | Elevated |
| Cortisol | Elevated |
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):
- Ask the nurse to stop the IV for at least 2 minutes
- Apply the tourniquet below the IV site
- Draw from a vein distal to (farther from the heart than) the IV site
- 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
A patient scheduled for a fasting glucose test reports they had coffee with cream 2 hours ago. What should the phlebotomist do?
A patient reports a latex allergy. Which of the following should the phlebotomist use?
Which patient should be positioned SUPINE (lying down) for a blood draw?
Which of the following tests typically require the patient to fast for 8-12 hours? (Select all that apply)
Select all that apply
A patient has had a mastectomy on their left side. Where should the phlebotomist draw blood?
Arrange the pre-collection verification steps in the correct order:
Arrange the items in the correct order
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
A patient on warfarin (blood thinner) has blood drawn. After the draw, the phlebotomist should:
Which of the following is TRUE about the effects of prolonged tourniquet application on test results?
Latex allergy cross-reactivity may occur in patients who also have allergies to:
Match each type of consent to its description:
Match each item on the left with the correct item on the right
Which of the following practices violates HIPAA patient privacy regulations?
A phlebotomist needs to draw blood from a patient who is combative and attempting to hit the phlebotomist. What is the BEST action?
A patient scheduled for a lipid panel ate breakfast 4 hours ago. The phlebotomist should:
Which of the following are TRUE about drawing blood from a patient receiving IV therapy? (Select all that apply)
Select all that apply
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?
The phlebotomist should ask the patient to make a gentle fist during venipuncture. Why should the patient NOT pump their fist repeatedly?
When verifying a patient's identity, which type of identifier is NOT acceptable?
A patient who is NPO (nothing by mouth) is allowed to have which of the following before a fasting blood draw?
Special Situations in Patient Identification
Emergency / Unknown Patients
When a patient cannot be identified (unconscious, unresponsive, no ID band):
- Do NOT draw blood until a temporary identification system is established
- The facility's emergency ID protocol assigns a temporary identifier (e.g., "Trauma Male 1" or a numeric code)
- A temporary armband with the assigned identifier must be placed on the patient
- All specimens must be labeled with this temporary identifier
- 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:
- Explain the importance of the test calmly and professionally
- Ask if there is a specific concern you can address (fear of needles, religious beliefs, etc.)
- If the patient still refuses, respect their decision — patient autonomy is paramount
- Document the refusal in the patient's record
- Notify the ordering physician of the refusal
- 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.
Arrange the correct sequence when a patient's identification band does not match the requisition:
Arrange the items in the correct order
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
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?
Match each special patient situation with the correct phlebotomy approach:
Match each item on the left with the correct item on the right