PERFORMING A VENIPUNCTURE
Collection Procedure:
LTD: Performing a Venipuncture Version 5
PERFORMING A VENIPUNCTURE
Venipuncture Site Selection: The median cubital and cephalic veins are most
commonly used for venipuncture. See below. Alternative sites are the basilic
vein on the dorsum of the arm or dorsal hand veins. Due to its close proximity to
the brachial artery and median nerve, the basilic vein, which is located on the
pinkie side of the arm, should be used only if there is not another more prominent
arm vein. Veins in the foot and ankle should be utilized only as a last resort.
Veins on the underside of the wrist should be avoided. Certain other sites should
also be avoided. (See picture.)
Sites to avoid:
Extensive scarring from burns or surgery
The upper extremity on the side that a mastectomy was performed.
Hematoma – A venipuncture should not be performed on a hematoma,
regardless of how small it may be. If there is not an alternate vein to draw,
the venipuncture should be performed distal to (below) the hematoma.
Intravenous therapy/Blood Transfusions – If it is not possible to draw the
opposite arm, then blood should be drawn from BELOW (distal to) the IV.
The tourniquet should be applied between the IV site and the venipuncture
site. If drawing above the IV site is the only option, then the IV infusion
must be turned off for at least 2 minutes before performing the
venipuncture. As there is still a risk that the sample could be
contaminated, you must document that the specimen was drawn above
(proximal to) an IV site and how many minutes the IV was turned off
before the draw occurred. The lab may reject the specimen as
contaminated based on the test results.
Cannula, Fistula or Vascular Graft – Blood should only be drawn from an
arm with a cannula, fistula or vascular graft with the provider’s prior
approval.
Edematous extremities – tissue fluid accumulation can alter test results.
Sites with noticeable skin conditions, such as eczema or infection.
Palpate and trace the path of the vein with the index finger. Arteries pulsate, are
more elastic and have a thicker wall than a vein. Thrombosed veins lack
resilience, feel cord-like and roll easily. If you are using a tourniquet for
preliminary vein selection, it should be released after one minute, left off for two
minutes and then reapplied before performing the venipuncture.
Procedure and Performance of a Venipuncture:
Select the proper size needle and attach it to the syringe or Vacutainer
hub.
When using a syringe, make sure that you pull the plunger in and out to
assure free motion.
Position the draw site for best visualization and/or palpation. Apply the
tourniquet 3-4 inches above the selected puncture site. Do not place
tightly or leave on for more than 1 minute. Instruct the patient to make a
fist and hold it; do not have them pump their hand. Select the
venipuncture site by palpating with the gloved index finger.
Prepare the patient’s arm using a Chlorhexadine wipe. Allow to air dry.
Do not dry the site with gauze and do not blow on the area to dry as this
will contaminate the site. After cleansing the area, if it is accidentally
touched before performing the venipuncture, it should be cleansed again.
Grasp the patient’s arm firmly using your thumb to draw the skin taut and
anchor the vein; do not use the index finger to pull the skin upward as this
increases the risk of sticking yourself. Swiftly insert the needle through
the skin, bevel side up, at a 15 – 30 degree angle with the skin, into the
lumen of the vein. (See diagram.)
If the patient complains of “shooting, electric-like pain, or tingling or
numbness proximal or distal to the puncture site,” the needle should be
removed immediately. It is possible that a nerve has been punctured
and possibly damaged. The venipuncture should be repeated in a
different site. A Supervisor or Manager should be notified and the incident
should be documented.
If an arterial puncture is suspected, as indicated by a bright red, quick,
pulsing flow, with or without rapid development of a hematoma, the needle
should be removed immediately. Forceful, direct pressure should be
applied to the site for a minimum of five minutes or until the bleeding has
stopped. The nursing staff should be notified, and they in turn must notify
the physician. A laboratory Supervisor or Manager should also be notified
and the incident should be documented.
If the blood does not begin to flow, reposition the needle by gently moving
the needle either backwards for forwards in the arm. If the blood is flowing
slowly, gently adjust the angle to see if the needle is sitting up against the
wall of the vein. Loosen the tourniquet, as it may be obstructing blood
flow. If you are vacutaining, try another tube – there may be no vacuum in
the tube.
After you have attempted to reposition the needle and are still not
successful, remove the tourniquet, remove the needle and begin the
process with a new site. In the case of a difficult venipuncture, an
individual may make a maximum of two attempts before having
someone else try. A third stick is allowable if a partial sample has been
obtained and you as the drawer feel reasonably confident that you can
obtain the specimen on the next try.
When the collection is complete, remove the tourniquet and place gauze
over the venipuncture site. While the needle is still in the vein, activate the
safety button with the tip of the index finger; the needle will automatically
retract from the vein and the safety device will cover the needle.
Apply adequate pressure to the puncture site to stop the bleeding and
avoid formation of a hematoma. If you used a needle and syringe, ask
your patient or a parent to apply pressure to the site so that you can fill
your tubes. Do not have the patient bend his/her arm; this may cause the
arm to start bleeding when the arm is straightened out.
If blood was drawn with a syringe, attach the blood transfer device to the
syringe and fill tubes according to the ‘Order of Draw for a Venipuncture’
(see picture).
Dispose of the contaminated materials and needle in the appropriate
waste containers.
Mix and label all appropriate tubes at the patient’s bedside. Return to your
patient and assess the site of the puncture. Apply a band-aid or CoFlex to
the site. (See “Use of Band-Aids in the Post-Phlebotomy Policy)
Additional Considerations When Performing a Venipuncture: The following
considerations should be taken into account:
Preventing a Hematoma: puncture only the uppermost wall of the vein.
Remove the tourniquet before removing the needle. Make sure the
needle fully penetrates the upper-most wall of the vein; partial penetration
may allow blood to leak into the tissue surrounding the vein. Adequate
pressure should be applied to stop the bleeding once the phlebotomy is
complete. A hematoma can cause a post-phlebotomy compression injury
to a nerve.
Preventing Hemolysis: Mix tubes gently, by inversion, 5-10 times – do not
shake them. Avoid drawing blood from a hematoma. If using a needle
and syringe, avoid drawing the plunger back too forcefully. Make sure the
venipuncture site is dry. Avoid probing for the vein. If using a blood
transfer device to fill vacutainer tubes, allow the vacuum to pull the blood
into the tubes; do not use the plunger on the syringe to force the blood into
the tubes more quickly.
Preventing Hemoconcentration: An increased concentration of larger
molecules and formed elements in the blood may be due to several
factors including prolonged tourniquet application (greater than 1 minute),
massaging, flicking, squeezing or probing the site, long-term IV therapy,
and sclerosed or occluded veins.
Preventing injury to a nerve, tendon, or muscle: Use careful palpitation
and appropriate angle of entry. Excessive probing (uncalculated side-to-side
movement) with the needle should be avoided.
Preventing dizziness or fainting and potential follow-up injuries due to a
fall: Be sure patient is seated in an appropriate draw chair and or lying in
a bed. Have appropriate back up staff as available.
Preventing of infection: Follow proper infection control policies.
Preventing injury from improper immobilization – Immobilize the patient
with care. If there is any concern regarding injury, contact nursing for
Inpatients and follow the Policy for Proper Handling of an Uncooperative
Patient.
Order of Draw for Venipuncture: Blood collection tubes must be drawn in a
specific order to avoid cross-contamination of additives between tubes. Follow
the order of draw listed here for both syringes (utilizing the blood transfer device)
and vacutainers:
1. Blood Cultures
2. Na Citrate Coagulation tubes – light blue top tube
3. Non-additive tube – red top tube
4. SST red or gold top – this tube contains a gel separator and clot
activators.
5. Sodium Heparin – green top tube
6. Lithium Heparin – green top tube
7. EDTA – lavender top tube
8. ACDA or ACDB – light yellow top tube
9. Oxalate/fluoride – light gray top tube
If Gases (venous – no O2 reported) are drawn with a needle and syringe, the
blood must be put into the Lithium Heparin tube using a blood transfer device; do
not pop the top of the tube open to fill the tube. Tubes with additives or clot
activators must be thoroughly mixed by gentle inversion, 5-10 times. Shaking
and vigorous mixing should be avoided.
References
Ernst, Dennis J. “Pediatric Pointers.” Center for Phlebotomy Education, Inc.
2004-2008, edited for accuracy 1/08.
Ernst, Dennis J. and Catherine Ernst. “Mastering Pediatric Phlebotomy.” Center
for Phlebotomy Education, Inc. Adapted from Phlebotomy for Nurses and
Nursing Personnel. HealthStar Press, Inc. 2001, updated 1/08.
Kiechle, Frederick L. So You’re Going to Collect a Blood Specimen: An
Introduction to Phlebotomy, 11th Edition. Northfield, IL: College of American
Pathologists, 2005.
NCCLS. Procedures for the Collection of Diagnostic Blood Specimens by
Venipuncture; Approved Standard—Sixth Edition. CLSI document H3-A6.
Wayne, PA: Clinical and Laboratory Standards Institute; 2007.
Proper Handling of an Uncooperative Patient in an Outpatient Setting – Akron
Children’s Hospital