BLOOD COLLECTION: ROUTINE VENIPUNCTURE AND SPECIMEN HANDLING

Objectives for the tutorial:

Describe and perform the venipuncture process including:
1. Appropriate clothing and protective equipment
2. Ensuring the comfort of the patient
3. Proper patient identification procedures.
4. Proper equipment selection and use.
5. Proper labeling procedures and completion of laboratory requisitions.
6. Order of draw for multiple tube phlebotomy.
7. Preferred venous access sites, and factors to consider in site selection, and ability to differentiate between the feel of a vein, tendon and artery.
8. Patient care following completion of venipuncture.
9. Safety and infection control procedures.
10. Quality assurance issues.
Identify the additive, additive function, volume, and specimen considerations to be followed for each of the various color coded tubes.
List six areas to be avoided when performing venipuncture and the reasons for the restrictions.
Summarize the problems that may be encountered in accessing a vein, including the procedure to follow when a specimen is not obtained.
List several effects of exercise, posture, and tourniquet application upon laboratory values.

VENIPUNCTURE PROCEDURE

The venipuncture procedure is complex, requiring both knowledge and skill to perform. Each phlebotomist generally establishes a routine that is comfortable for her or him.

Phlebotomists are considered to have occupational exposure to blood borne pathogens. The performance of routine vascular access procedures by skilled phlebotomists requires, at a minimum, the use of gloves to prevent contact with blood. Airborne precautions may be considered to provide a level of safety against infectious diseases such as tuberculosis, influenza, and COVID-19. Precautions include a medical grade face mask. With risk for blood spatter a face shield provides protection. A face mask reduces risk for blood culture specimen contamination.

Laboratory coats or work smocks are not typically needed as personal protective equipment during routine venipuncture, but an employer must assess the workplace to determine whether certain tasks, workplace situations, or employee skill levels may result in an employee's need for laboratory coats or other personal protective equipment to prevent contact with blood. It is an employer's responsibility to provide, clean, repair, replace, and/or dispose of personal protective equipment/clothing. As part of presenting a professional appearance, an institutional dress code may include wearing of a laboratory coat or smock.

Patient identification is critical for safety. At least two patient identifiers, such as name and date of birth, are needed. Label collection tubes after identification of the patient. Interruptions and distractions during medical encounters and procedures should be avoided.

Several essential steps are required for every successful collection procedure:

Patient comfort. Is the seating comfortable and has the patient been seated for at least 5 minutes to avoid being rushed or confused?
Carry out hand hygiene before and after each patient procedure, before putting on and after removing gloves.
Identify the patient using two different identifiers, asking open ended questions such as, "What is your name?" and "What is your date of birth?"
Assess the patient's physical disposition (i.e. diet, exercise, stress, basal state).
Check the requisition form for requested tests, patient information, and any special requirements.
Label the collection tubes at the bedside or drawing area.
Select a suitable site for venipuncture.
Prepare the equipment, the patient and the puncture site.
Perform the venipuncture, collecting the sample(s) in the appropriate container(s).
Recognize complications associated with the phlebotomy procedure.
Assess the need for sample recollection and/or rejection.
Safely discard potentially infectious materials.
Promptly send the specimens with the requisition to the laboratory.

ORDER FORM / REQUISITION

A requisition form must accompany each sample submitted to the laboratory. This requisition form must contain the proper information in order to process the specimen. The essential elements of the requisition form are:

Patient's surname, first name, and middle initial.
Patient's ID number.
Patient's date of birth and gender.
Requesting physician's complete name.
Source of specimen. This information must be given when requesting microbiology, cytology, fluid analysis, or other testing where analysis and reporting is site specific.
Date and time of collection.
Initials of phlebotomist.
Indicating the test(s) requested.

An example of a simple requisition form with the essential elements is shown below:

LABELING THE SAMPLE

A properly labeled sample is essential so that the results of the test match the patient. The key elements in labeling are:

Patient's surname, first and middle.
Patient's ID number.
NOTE: Both of the above MUST match the same on the requisition form.
Date, time and initials of the phlebotomist must be on the label of EACH tube.

Automated systems may include labels with bar codes.

Examples of labeled collection tubes are shown below:

EQUIPMENT:

THE FOLLOWING ARE NEEDED FOR ROUTINE VENIPUNCTURE:

Evacuated Collection Tubes - The tubes are designed to fill with a predetermined volume of blood by vacuum. The rubber stoppers are color coded according to the additive that the tube contains. Various sizes are available. Blood should NEVER be poured from one tube to another since the tubes can have different additives or coatings (see illustrations at end).
Needles - The gauge number indicates the bore size: the larger the gauge number, the smaller the needle bore. Needles are available for evacuated systems and for use with a syringe, single draw or butterfly system.
Holder/Adapter - use with the evacuated collection system.
Tourniquet - Wipe off with alcohol and replace frequently.
Alcohol Wipes - 70% isopropyl alcohol.
Povidone-iodine wipes/swabs - Used if blood culture is to be drawn.
Gauze sponges - for application on the site from which the needle is withdrawn.
Adhesive bandages / tape - protects the venipuncture site after collection.
Needle disposal unit - needles should NEVER be broken, bent, or recapped. Needles should be placed in a proper disposal unit IMMEDIATELY after their use.
Gloves - can be made of latex, rubber, vinyl, etc.; worn to protect the patient and the phlebotomist.
Syringes - may be used in place of the evacuated collection tube for special circumstances.

ORDER OF DRAW

Blood collection tubes must be drawn in a specific order to avoid cross-contamination of additives between tubes. The recommended order of draw for plastic collection tubes is:

First - blood culture bottle or tube (yellow or yellow-black top)
Second - coagulation tube (light blue top). If just a routine coagulation assay is the only test ordered, then a single light blue top tube may be drawn. If there is a concern regarding contamination by tissue fluids or thromboplastins, then one may draw a non-additive tube first, and then the light blue top tube.
Third - non-additive tube (red top)
Last draw - additive tubes in this order:
1. SST (red-gray or gold top). Contains a gel separator and clot activator.
2. Sodium heparin (dark green top)
3. PST (light green top). Contains lithium heparin anticoagulant and a gel separator.
4. EDTA (lavender top)
5. ACDA or ACDB (pale yellow top). Contains acid citrate dextrose.
6. Oxalate/fluoride (light gray top)

NOTE:Tubes with additives must be thoroughly mixed. Erroneous test results may be obtained when the blood is not thoroughly mixed with the additive. Transferring a sample from one collection tube to another or mixing blood from different collection tubes must be avoided.

PROCEDURAL ISSUES

PATIENT RELATIONS AND IDENTIFICATION:

The phlebotomist's role requires a professional, courteous, and understanding manner in all contacts with the patient. Greet the patient and identify yourself and indicate the procedure that will take place. Effective communication - both verbal and nonverbal - is essential.

Proper patient identification MANDATORY. If an inpatient is able to respond, ask for a full name and always check the armband or bracelet for confirmation. For an inpatient DO NOT DRAW BLOOD IF THE ARMBAND OR BRACELET IS MISSING. For an inpatient the nursing staff can be contacted to aid in identification prior to proceeding.

An outpatient must provide identification other than the verbal statement of a name. Using the requisition for reference, ask a patient to provide additional information such as a birthdate. A government issued photo identification card such as a driver's license can aid in resolving identification issues.

If possible, speak with the patient during the process. The patient who is at ease will be less focused on the procedure. Always thank the patient and excuse yourself courteously when finished.

PATIENT'S BILL OF RIGHTS:

The Patient's Bill of Rights has been adopted by many hospitals as declared by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). The basic patient rights endorsed by the JCAHO follow in condensed form are given below.

The patient has the right to:

Impartial access to treatment or accommodations that are available or medically indicated, regardless of race, creed, sex, national origin, or sources of payment for care.
Considerate, respectful care.
Confidentiality of all communications and other records pertaining to the patient's care.
Expect that any discussion or consultation involving the patient's case will be conducted discretely and that individuals not directly involved in the case will not be present without patient permission.
Expect reasonable safety congruent with the hospital practices and environment.
Know the identity and professional status of individuals providing service and to know which physician or other practitioner is primarily responsible for his or her care.
Obtain from the practitioner complete and current information about diagnosis, treatment, and any known prognosis, in terms the patient can reasonably be expected to understand.
Reasonable informed participation in decisions involving the patient's health care. The patient shall be informed if the hospital proposes to engage in or perform human experimentation or other research/educational profits affecting his or her care or treatment. The patient has the right to refuse participation in such activity.
Consult a specialist at the patient's own request and expense.
Refuse treatment to the extent permitted by law.
Regardless of the source of payment, request and receive an itemized and detailed explanation of the total bill for services rendered in the hospital.
Be informed of the hospital rules and regulations regarding patient conduct.

VENIPUNCTURE SITE SELECTION:

Although the larger and fuller median cubital and cephalic veins of the arm are used most frequently, the basilic vein on the dorsum of the arm or dorsal hand veins are also acceptable for venipuncture. Foot veins are a last resort because of the higher probability of complications.

Certain areas are to be avoided when choosing a site:

Extensive scars from burns and surgery - it is difficult to puncture the scar tissue and obtain a specimen.
The upper extremity on the side of a previous mastectomy - test results may be affected because of lymphedema.
Hematoma - may cause erroneous test results. If another site is not available, collect the specimen distal to the hematoma.
Intravenous therapy (IV) / blood transfusions - fluid may dilute the specimen, so collect from the opposite arm if possible. Otherwise, satisfactory samples may be drawn below the IV by following these procedures:
- Turn off the IV for at least 2 minutes before venipuncture.
- Apply the tourniquet below the IV site. Select a vein other than the one with the IV.
- Perform the venipuncture. Draw 5 ml of blood and discard before drawing the specimen tubes for testing.
Lines - Drawing from an intravenous line may avoid a difficult venipuncture, but introduces problems. The line must be flushed first. When using a syringe inserted into the line, blood must be withdrawn slowly to avoid hemolysis.
Cannula/fistula/heparin lock - hospitals have special policies regarding these devices. In general, blood should not be drawn from an arm with a fistula or cannula without consulting the attending physician.
Edematous extremities - tissue fluid accumulation alters test results.

PROCEDURE FOR VEIN SELECTION:

Palpate and trace the path of veins with the index finger. Arteries pulsate, are most elastic, and have a thick wall. Thrombosed veins lack resilience, feel cord-like, and roll easily.
If superficial veins are not readily apparent, you can force blood into the vein by massaging the arm from wrist to elbow, tap the site with index and second finger, apply a warm, damp washcloth to the site for 5 minutes, or lower the extremity over the bedside to allow the veins to fill.

PERFORMANCE OF A VENIPUNCTURE:

Approach the patient in a friendly, calm manner. Provide for their comfort as much as possible, and gain the patient's cooperation.
Identify the patient correctly.
Properly fill out appropriate requisition forms, indicating the test(s) ordered.
Verify the patient's condition. Fasting, dietary restrictions, medications, timing, and medical treatment are all of concern and should be noted on the lab requisition.
Check for any allergies to antiseptics, adhesives, or latex by observing for armbands and/or by asking the patient.
Position the patient. The patient should either sit in a chair, lie down or sit up in bed. Hyperextend the patient's arm.
Apply the tourniquet 3-4 inches above the selected puncture site. Do not place too tightly or leave on more than 2 minutes (and no more than a minute to avoid increasing risk for hemoconcentration). Wait 2 minutes before reapplying the tourniquet.
The patient should make a fist without pumping the hand.
Select the venipuncture site.
Prepare the patient's arm using an alcohol prep. Cleanse in a circular fashion, beginning at the site and working outward. Allow to air dry.
Grasp the patient's arm firmly using your thumb to draw the skin taut and anchor the vein. The needle should form a 15 to 30 degree angle with the surface of the arm. Swiftly insert the needle through the skin and into the lumen of the vein. Avoid trauma and excessive probing.
When the last tube to be drawn is filling, remove the tourniquet.
Remove the needle from the patient's arm using a swift backward motion.
Press down on the gauze once the needle is out of the arm, applying adequate pressure to avoid formation of a hematoma.
Dispose of contaminated materials/supplies in designated containers.
Mix and label all appropriate tubes at the patient bedside.
Safely dispose of potentially infectious materials.
Deliver specimens promptly to the laboratory.

COLLECTION TUBES FOR PHLEBOTOMY

Collection tubes can vary in size for volume of blood drawn, appropriate to the tests ordered with sample size required, and vary in the kind of additive for anticoagulation, separation of plasma, or preservation of analyte. Larger tube sizes typically provide for collection of samples from 6 to 10 mL.
Smaller collection tubes for sample sizes of 2 mL or less may be appropriate in situations where a smaller amount blood should be drawn, as in pediatric patients, or to minimize hemolysis during collection, or to avoid insufficient sample volume in the collection tube.

Red Top
ADDITIVE	None
MODE OF ACTION	Blood clots, and the serum is separated by centrifugation
USES	Chemistries, Immunology and Serology, Blood Bank (Crossmatch)

Gold Top
ADDITIVE	None
MODE OF ACTION	Serum separator tube (SST) contains a gel at the bottom to separate blood from serum on centrifugation
USES	Chemistries, Immunology and Serology

Light Green Top
ADDITIVE	Plasma Separating Tube (PST) with Lithium heparin
MODE OF ACTION	Anticoagulates with lithium heparin; Plasma is separated with PST gel at the bottom of the tube
USES	Chemistries

Purple Top
ADDITIVE	EDTA
MODE OF ACTION	Forms calcium salts to remove calcium
USES	Hematology (CBC) and Blood Bank (Crossmatch); requires full draw - invert 8 times to prevent clotting and platelet clumping

Light Blue Top
ADDITIVE	Sodium citrate
MODE OF ACTION	Forms calcium salts to remove calcium
USES	Coagulation tests (protime and prothrombin time), full draw required

Green Top
ADDITIVE	Sodium heparin or lithium heparin
MODE OF ACTION	Inactivates thrombin and thromboplastin
USES	For lithium level, use sodium heparin For ammonia level, use sodium or lithium heparin

Dark Blue Top
ADDITIVE	EDTA-
MODE OF ACTION	Tube is designed to contain no contaminating metals
USES	Trace element testing (zinc, copper, lead, mercury) and toxicology

Light Gray Top
ADDITIVE	Sodium fluoride and potassium oxalate
MODE OF ACTION	Antiglycolytic agent preserves glucose up to 5 days
USES	Glucoses, requires full draw (may cause hemolysis if short draw)