MT116: CLINICAL CHEMISTRY LABORATORY: VENIPUNCTURE

VENIPUNCTURE
Merriam-Webster:
Venipuncture is a surgical puncture of a vein especially for the withdrawal
of blood or for intravenous medication
Phlebotomy Essentials:
It is the primary duty of the phlebotomist to collect blood specimens for
laboratory testing.

VENIPUNCTURE OVERVIEW
• Venipuncture is the most common way to collect blood specimens for
laboratory testing and the most frequent procedure performed by a
phlebotomist.
• The first and most important step is patient identification
• Venipuncture techniques covered include ETS, butterfly needle and Most common source errors in the hospital – clerical errors (anything
syringe procedures on arm and hand veins. handwritten)
PATIENT REGISTRATION VENIPUNCTURE STEPS
• Patient MUST be registered with the healthcare facility or specimen 1. RECEIVE AND REVIEW THE REQUISITION TEST
collection center BEFORE specimen collection can take place. • In reviewing a requisition, the phlebotomist must:
• The patient’s identity—including full name, date of birth, sex, address, ✓ Check to see that all required information is present and complete.
and proof of ID, should be established and entered into the facility ✓ Make certain the request matches the labels generated
database. ✓ Resolve any problems or discrepancies by contacting the provider
• This process typically involves assignment of patient-specific identifier ✓ Verify the tests to be collected and time and date of collection
which will appear on all test requests and specimen labels for that ✓ Identify diet restrictions or other special circumstances that must be
patient met prior to collection
REGISTRATION ✓ Determine test status and collection priority.
- Is a routine process during which data are collected that creates a patient (refer to table 1.1 for the table next page).
record for the specific individual that is being admitted to the facility or 2. APPROACH, GREET AND IDENTIFY THE PATIENT
the specimen collection facility. Approaching the Patient
REQUEST FOR TESTING • Outpatient: summoned into the drawing area from the waiting room,
• Typically, a physician or other qualified healthcare professional requests make sure they are safely situated in the phlebotomy chair with arm
laboratory testing—with exceptions on certain laboratory tests that can rest down
be performed at home. • Inpatient: arrange test requests according to priority and review to
• Done in a Requisition or Request Form. see necessary equipment is on the blood collecting tray
Looking for Signs
• Of specific importance to phlebotomists are signs indicating infection-
control precautions are to be followed when entering the room and
signs that prohibit blood draw from certain arm
• A sign with DNR (do not resuscitate) means the patient should NOT
be revived if he or she stops breathing
Greeting the Patient and Identifying Yourself
• “Good morning, I am ____, your medical technologist/ phlebotomist.
I am here to collect a blood specimen if it is alright with you..”
• The patient has the right to refuse to have their blood drawn
Patient Identification
• The most crucial step in specimen collection
• According to CLSI, ask the patient to STATE his or her full name and
date of birth and spell the first and last name
Sample picture
• For inpatients, check ID band or bracelet

3. EXPLAIN THE PROCEDURE AND OBTAIN CONSENT

Explaining the Procedure
• A statement of your intent to collect a specimen for a blood test is
usually sufficient for them to understand what is about to occur
• Explain what will happen in simple terms
• Sign language or other nonverbal means may be needed
• NEVER attempt to explain the purpose of a test
Obtaining Consent
• ALWAYS explain why you are there and ask the patient for permission
to collect the specimen
• NEVER collect a blood specimen WITHOUT PERMISSION or AGAINST
THE WILL of a patient.
4. VERIFY COLLECTION REQUIREMENTS
Verifying Diet Restrictions:
• The most common diet requirement is for the patient to be fasting
for a certain amount of time— usually 8 to 12 hours
• Fasting vs NPO
• Note if “underfast” or “overfast” or “nonfasting”
Table 1.1 STATUS MEANING WHEN USED COLLECTION CONDITIONS TEST SAMPLES PRIORITY
STAT Immediately (from Urgent test on critical Immediately collect, test, Glucose, Electrolytes, Cardiac FIRST
Latin statim) patient and report. Prio ER STATS Enzymes
Med Emerg Medical emergency Same as STAT Same as STAT Same as STAT Same as STAT
Timed At a specific time Timing is critical for Record actual time 2-hr PP GTT, cortisol, cardiac, culture Second
accurate results collected
ASAP As soon as possible Needed soon but not Follow hospital protocol Electrolyte, glucose 2nd or 3rd
critical for type of test
Preop Before an operation Determine eligibility for Collect BEFORE px goes to CBC, PTT, Plt function Same as ASAP
surgery surgery
Postop After an operation Assess px condition after Collect AFTER px surgery CBC Same as ASAP
surgery
Fasting No food or drink Eliminate diet effects on Verify px fasting Glucose, cholesterol, triglycerides 4th
EXCEPT water test result
NPO Nothing by mouth Prior to surgery Do NOT give px food or N/A None
(Latin nil per os) water
Routine Established procedure Used to establish No urgency CBC, Chemistries None
diagnosis
Addressing Sensitivities - The tourniquet end should point toward the shoulder to prevent
• Certain allergies: latex, adhesive bandages, or antiseptics them from contaminating the blood collection site.
• Use other alternatives NOTE:
5. SANITIZE HANDS AND PUT ON GLOVES What NOT to do during tourniquet placing
• Proper hand hygiene plays a major role in preventing spread of • NEVER apply tourniquet over an open sore
infection by protecting the phlebotomist, patient and other from • Do NOT make the patient pump the fist.
contamination 7. SELECT A VEIN, RELEASE THE TOURNIQUET, AND ASK THE PATIENT
• Hand-washing or alcohol-based hand sanitizers TO OPEN THE FIST
• Double gloving may be necessary. • The preferred puncture site in the antecubital area/fossa of the arm,
6. POSITION PATIENT, APPLY TOURNIQUET, AND ASK THE PATIENT TO where several large veins normally lie close to the surface
MAKE A FIST • Most prominent veins: medium cubital, cephalic, and basilic veins.
• For venipuncture in the antecubital area, the patient’s arm should • Generally, the most prominent veins are in the dominant arm;
extend downward in a straight line from should to wrist and not be • But the non-dominant arm is likely to be used and be less disturbed
bent during the healing process
• Prevents backflow of tube contents into the patient’s veins • To locate a vein, palpate the area by pushing down on the skin with the
TOURNIQUET APPLICATION tip of the index finger
1. Place the tourniquet around the arm 3-4 inches above the intended • Then, determine the patency, size and depth, and the direction or path
venipuncture site. they follow
Rationale: • Depth is indicated by the degree of pressure required to feel it
- If closer to the site, the vein may collapse as the blood is withdrawn. • An artery has a PULSE and MUST BE AVOIDED
If too far above the site, it may be ineffective.
2. Grasp one side of the tourniquet in each hand a few inches from the
end.
Rationale:
- Tension is needed to the tourniquet will be snug when tied. Too
much tension will be too tight and roll up and twist and cause
discomfort
3. Apply a small tension and maintain throughout the process
Rationale:
- Tension is needed to the tourniquet will be snug when tied. Too
much tension will be too tight and roll up and twist and cause
discomfort
4. Bring the two sides together and grasp them both between the thumb
and forefinger of the right hand
Rationale:
- This is preparation for crossing the sides over each other
5. Reach over the right hand, and grasp the right side of the tourniquet
between the thumb and forefinger of the left hand and release it from the
grip of the right hand
6. Cross the left end over the right end near the index finger, grasping both
sides together between the thumb and forefinger of the left hand
Rationale:
- If there is too much space between the left index finger and the px
arm, the tourniquet will be too loose
7. Use other the left middle finger or the right index finger to tuck a
portion of the left side under the right side and pull it into a loop
Rationale 8. CLEAN AND AIR-DRY THE SITE
- The loop allows the tourniquet to be released quickly by a slight tug • Must be cleaned with antiseptic prior to venipuncture—usually with 70%
on the end of the tourniquet that forms it. isopropyl alcohol
8. A properly tied tourniquet has the ends pointing towards the shoulder • Use back and forth friction to clean an area 2 to 3 inches in diameter
Rationale around the selected site
• Allow natural air drying for 30 sec to 1 min
• DO NOT: dry with gauze, fan with hand or bow on it, touch site after 12. ESTABLISH BLOOD FLOW, RELEASE THE TOURNIQUET, AND ASK PX
cleaning TO OPEN FIST
9. PREPARE COLLECTION EQUIPMENT • In a syringe system, a flash of blood in the syringe hub indicates successful
• Assembling the blood collection equipment while waiting for the site to entry of the vein
dry saves time • Slowly pull back the plunger with your free hand
• Choose the collection system, needle size, and tube volume according to • Pulling the plunger quickly can hemolyze the specimen
the age of the patient, size and location of the vein, and amount of blood • Release the tourniquet within one minute.
to be collected 13. FILL, REMOVE, AND MIX TUBES IN ORDER OF DRAW OR FILL
VENIPUNCTURE SYSTEMS SYRINGE
1. Evacuated Tube System (ETS) • Different types of additives are used in blood collection, and the type
• Closed system in which the px blood f lows through a needle required depends on the test ordered
inserted into a vein directly into a collection tube without exposure • Additives are available in liquid, spray-dried or powder forms—powdered
to air or outside contaminant additive should be lightly tapped prior to use to settle the additive at the
• Numerous tubes can be collected in a single venipuncture bottom of the tube
• Three components: multisampling needle, tube holder, and • Tube must be gently inverted 3 to 10 times, depending on the type of
evacuated tube/ s additive.
2. Syringe System
• This system consists of a sterile syringe needle called a hypodermic
needle and a sterile plastic syringe
• Syringe needles are generally gauges 21 to 23 on 1 or 1.5-inch
lengths
• Most common volumes used for phlebotomy are 3, 5, and 10 mL
3. Syringe Transfer Device DO NOT OVERMIX.
• Allows the safe transfer of blood into the tubes without using the ANTICOAGULANTS
syringe needle or removing tube stopper • Anticoagulants prevent blood from clotting/ coagulating either through:
• After draw, remove the needle, discard, then attach the transfer (a) binding/chelating calcium; or (b) by inhibiting formation of thrombin
device to the hub of the syringe • If a test requires whole blood or plasma, specimen must be collected in
4. Blood Collection Set a tube with anticoagulant
• For small or difficult veins such as hand veins and veins of elderly • Specimen collected in anticoagulant can be separated through settling or
and pediatric patients centrifugation
• Allow more flexibility and precision than a needle and tube holder or • The most common anticoagulants are ethylenediaminetetraacetic acid,
needle and syringe citrates, heparin, and oxalates.
• 0.5 to 0.75-in butterfly needle permanently connected to 5- to 12in EDTA ETHYLENEDIAMINETETRAACETIC ACID
length of tubing in 21, 23, or 25-gauge needles, attached to a syringe Ethylenediaminetetraacetic acid is commonly available as dipotassium
or evacuated tube holder (K2EDTA) or tripotassium (K3EDTA) spray dried or liquid K3EDTA
• Action: chelates calcium to form an insoluble salt
10. REAPPLY THE TOURNIQUET, AND UNCAP AND INSPECT THE NEEDLE • Tube color/s: lavender, pink plastic-top for blood bank, royal blue-top
• Reapply the tourniquet, be careful not to touch the cleaned area with lavender label, tan-top for lead analysis, white-top with thixotropic
• Some tests (i.e. lactic acid) that must be tube collected WITHOUT using a gel separator, lavender microtubes
tourniquet • Uses: WB for hematology tests
• Remove the needle cover and visually inspect the needle. • # of inversions: 8 to 10
11. ASK PX TO REMAKE FIST, ANCHOR THE VEIN AND INSERT THE
• Spray-dried EDTA is more preferred than liquid EDTA
NEEDLE
• Dilutional effect is more pronounced if the tubes are not filled to its
Anchoring
stated volume
• To anchor veins, place thumb 1 to 2 inches below and slightly to the side
• Anticoagulant excess: RBC shrinkage.
of the intended venipuncture site
CITRATE
• This stretches the skin taut, anchoring the vein and helping to keep it
Most common is sodium citrate
from moving or rolling to the side upon needle entry
• Action: chelates calcium to form an insoluble salt
• Patient is less likely to pull away from grasp and needle is more likely to
• Tube color/s: light blue
stay in the vein
• Uses: coagulation tests (e.g. PT, aPTT)
Needle Insertion
• # of inversions: 3 or 4 gentle inversions
• Bevel should be facing up
• 9:1 blood to anticoagulant ratio.
• Insert at 30-degree angle or less, depending on the depth of the vein
HEPARIN
• Use one smooth, steady, forward motion to penetrate first the skin and
Common formulations: Ammonium, lithium, and sodium heparin
then the vein
• Action: inhibit thrombin and factor X
• Discontinue immediately if px complains of marked pain
• Tube color/s: green-top or light green, mottled green and gray-top, royal
• When needle enters the vein, you will slight a slight “give” or decrease in
blue-top with green label, green-top and light green microtubes, red-
resistance.
banded and green-banded microhematocrit
• Uses: chemistry tests (ammonia, plasma hgb), STAT electrolytes, blood
gas determination
• # of inversions: 5 to 10.
OXALATES
• Most commonly used is potassium oxalate
• Action: chelates calcium to form insoluble salt
• Tube color/s: gray-top tubes or microcontainers
• Uses: glucose testing
• # of inversions: 8 to 10.
 SPECIAL-USE ANTICOAGULANTS CLSI ORDER OF DRAW
ACID CITRATE DEXTROSE Evacuated Tube System
• Used in immunohematology such as DNA testing and human leukocyte
antigen (HLA) phenotyping—paternity evaluation and determine
transplant compatibility
• Action: acid citrate - prevents coagulation by chelating calcium; dextrose
- RBC nutrient and preservative
• Tube color/s: yellow tops
• # of inversion: 8.
CITRATE PHOSPHATE DEXTROSE Syringe System
• Used in collecting units of blood for transfusion
• Action: citrate - prevents coagulation by chelating calcium; phosphate -
stabilizes pH; dextrose - RBC nutrient and preservative.
ANTIGLYCOLYTIC AGENTS
SODIUM FLUORIDE
• Used in serum specimen
• Can be used in combination with other anticoagulants
• Action: Preserves glucose by preventing glycolysis and inhibits bacterial
growth
• Tube color/s: gray top
• # of inversion: 5 to 10.
CLOT ACTIVATORS • Some Silly Ladies Love Green institutions prefer separate order of draw
SERUM-SEPARATOR TUBES (SST) OR RED-TOP TUBES for syringe system
• Has glass particles and clotting factors (thrombin) • Tubes most Gray Roses affected by microclots are f illed as soon as
• Action: ENHANCES coagulation to collect serum specimen possible
• Tube color/s: red-top, orange-top, gold-top • Blood the entered the syringe last is the freshest.
• # of inversion: 5 to 10 14. WITHDRAW NEEDLE, PLACE GAUZE, ACTIVATE SAFETY FEATURE,
AND APPLY PRESSURE
• Discontinue draw after the last tube has been removed from the holder
or adequate amount of blood has been collected by the syringe
• Withdraw the needle from the arm abdomen quickly place the gauze pad
over the venipuncture site
• DO NOT place gauze and apply pressure WHILE the needle is in the vein
• Apply pressure for three to five minutes or until the bleeding stops.
15. DISCARD NEEDLE, ATTACH TRANSFER DEVICE, TRANSFER BLOOD,
AND DISCARD SYRINGE
• After activating its safety feature, remove the syringe needle, discard it
into a sharps container and attach syringe transfer device
• Hold syringe vertically with the tube at the bottom
• Transfer appropriate amount according to the correct blood-to-additive
ratio
• When transfer is complete, discard the syringe and attach transfer device
into sharps container.
16. LABEL AND PREPARE TUBES FOR HANDLING AND TRANSPORT
• Hand-print label with a permanent ink pen
• Pertinent labels should include:
✓ Px first name and last name
✓ Date of birth
✓ Date and time of collection
✓ Phlebotomist’s initials
✓ Additional info (such as ‘fasting’).
17. CHECK THE PX ARM, AND APPLY BANDAGE • If seizure occurs, phlebotomist must
18. DISPOSED OF USED MATERIALS immediately remove and discard the tourniquet
19. THANK THE PX, REMOVE GLOVES, AND SANITIZE HANDS and needle
20. TRANSPORT SPECIMEN TO THE LAB PROMPTLY • Notify the nurse or designated first aid
provided at the facility
COMPLICATIONS ENCOUNTERED IN VENIPUNCTURE o VOMITING
o ECCHYMOSIS (BRUISE) • Provide the px with appropriate container and
• Most common encountered complication in tissues then notify the nurse or other healthcare
venipuncture personnel
• Caused by leakage of small amount of blood in • Reposition head of the px as to not aspirate
the tissue around the puncture site
• Prevent by applying direct pressure to the site VENIPUNCTURE IN SPECIAL SITUATIONS
with gauze pad EDEMA
o HEMATOMA - Edematous sites should be avoided for venipuncture because veins are
• Leakage of large amount of blood around the hard to find and the specimen may be contaminated with tissue fluid.
puncture site causing it to swell BURNED, DAMAGED, SCARRED AND OCCLUDED VEINS
• If seen during venipuncture, remove needle - Should be avoided as they do not allow the blood to flow freely.
immediately and apply pressure for at least 2 OBESITY
minutes - May use blood pressure cuff to help locating a vein
• Commonly occur when needle goes through the - Cuff should not be inflated any higher than the px diastolic pressure.
vein or when bevel is only partially in the when INTRAVENOUS THERAPY
o FAINTING (SYNCOPE) - Must be avoided if possible and draw blood in the opposite arm
• Before drawing blood, ask px if they had prior - If there is no alternative, blood should be drawn below the IV site, with
episodes of fainting during or after blood the tourniquet also placed below the IV site
collection - Stop the infusion for 2 minutes before drawing blood
• If px begins to faint, phlebotomist should
- Indicate in the form that specimen was obtained from an IV arm
remove the tourniquet and needle immediately
MASTECTOMY
• Lower px head and loosen any constrictive
- Pressure from the tourniquet can lead to pain or lymphostasis from
clothing
o HEMOCONCENTRATION accumulated lymph fluid
- Draw blood from the other arm.
• Increased concentration of cells, larger
molecules, and analytes in the blood due to shift INABILITY TO OBTAIN A BLOOD SPECIMEN
in water balance Failure to Draw Blood
• Can falsely elevate cell counts, hemogloblin, • One reason for failure to draw blood is that the vein is missed—usually
hematocrit, diff count, albumin, total protein, due to improper needle positioning
glucose, potassium, calcium, and triglycerides • Needle should be inserted bevel up, at an angle of less than 30 degrees
• Caused by leaving the tourniquet on the px arm • Reposition the needle by slightly withdrawing or advancing the needle
for longer than 1 minute • Occasionally, evacuated tube has insufficient vacuum
o HEMOLYSIS • If two unsuccessful attempts have been made, ask assistance of another
• Rupture of red blood cells with consequent phlebotomist
escape of hemoglobin
• Hemolysis can occur if the phlebotomist used
too small needle during a difficult draw; drew
blood through existing hematoma; pulled back
too quickly on the plunger; too vigorous
mixture; contaminated specimen
• Can elevate potassium, serum lactate
dehydrogenase, aspartate aminotransferase
o PETECHIAE
• Small red spots indicating that small amounts of
blood have escaped into the skin
• Possible hemostatic abnormality
Patient Refusal
o ALLERGIC REACTIONS • Patient has the right to refuse blood collection
• Possible allergies to skin disinfectants, adhesive • If gentle urging does not persuade the patient to allow blood to be drawn,
bandages and tape alert the nurse
• Phlebotomist should use hypoallergenic tape, or
• Do NOT force an uncooperative px
latex-free gloves, or apply pressure until
bleeding stops • For child px, let parent or guardian hold the px.
o Nerve Damage Missing Patient
• Phlebotomist should select appropriate veins • Absence of px should be reported to the nurse.
and should not blindly probe the arm with the GENERAL BLOOD COLLECTION EQUIPMENT
needle
• If px complains of shooting or sharp pain,
tingling, or numbness of the arm, remove
tourniquet and needle immediately
• Other attempt can be made in the other arm
o SEIZURES
• • Possible preexisting condition or as a
response to the needlestick
Phlebotomy Chair
Blood drawing station
 VENIPUNCTURE EQUIPMENT
Handheld Carriers
Phlebotomy carts

Antiseptics

Examples of antiseptics to used in blood collection:

• 70% ethyl alcohol
• 70% isopropyl alcohol (isopropanol)
• Bezalkonium chloride (e.g. Zephiran chloride)
• Chlorhexidine gluconate
• Hydrogen peroxide
• Povidone iodine (0.1% to 1%)
• Tincture of iodine

SUMMARY OF VENIPUNCTURE STEPS USING THE SYRINGE METHOD

1. Receive, review and accession the test request
2. Approach, greet and identify the patient
3. Explain the procedure and obtain consent
4. Verify collection requirements, and identify sensitivities and potential
problems
5. Sanitize hands, and put on gloves
6. Position the patient, apply tourniquet, and ask the patient to make a fist
7. Select vein, release tourniquet, and ask the patient to open the fist
8. Clean and air-dry the site
9. Prepare equipment
10. Reapply tourniquet, and uncap and inspect the needle.
11.Ask the patient to remake a fist, then anchor the vein and insert the needle
12. Establish blood flow, release the tourniquet, and ask patient to open fist
13. Fill the syringe
14.Withdraw the needle, place gauze, activate the safety device, and apply
pressure
15.Remove the needle from the syringe and discard it in a sharps container.
16.Attach the syringe hub to the transfer device hub, rotating it to ensure
secure attachment
17.Hold the syringe vertically with the tip down, and transfer device at the
bottom
18.Place the ETS tube holder in the transfer device, and push it all the way to
the end
19.Let the tubes fill using the vacuum of the tube
20.Discard the syringe and transfer device in the sharps container.
21.Thank the patient and clean up after yourself