Venipuncture
By
V.Merlin
17BEN025
VENIPUNCTURE
In medicine, venipuncture or venepuncture
is the process of obtaining intravenous
access for the purpose of intravenous
therapy or for blood sampling of venous
blood. In healthcare, this procedure is
performed by medical laboratory scientists,
medical practitioners, some EMTs,
paramedics, phlebotomists, dialysis
technicians, and other nursing staff. In
veterinary medicine, the procedure is
performed by veterinarians and veterinary
technicians.
It is essential to follow a standard procedure for the collection of blood
specimen to get the accurate laboratory results. Any kind of error in collection
of blood or filing the test tubes may lead erroneous laboratory results.
Venipuncture is one of the most routinely performed invasive procedures and
is carried out for any of five reasons:
• To obtain blood for diagnostic purposes;
• To monitor levels of blood components (Lavery & Ingram 2005);
• To administer therapeutic treatments including medications, nutrition, or
chemotherapy;
• To remove blood due to excess levels of iron or erythrocytes (red blood
cells); or
• To collect blood for later uses, mainly transfusion either in the donor or in
another person.
How the Test is Performed
Most of the time, blood is drawn from a vein located on the inside of the
elbow or the back of the hand.
• The site is cleaned with germ-killing medicine (antiseptic).
• An elastic band is put around the upper arm to apply pressure to the
area. This makes the vein swell with blood.
• A needle is inserted into the vein.
• The blood collects into an airtight vial or tube attached to the needle.
• The elastic band is removed from your arm.
• The needle is taken out and the spot is covered with a bandage to stop
bleeding.
Venipuncture Procedure
The area where the blood is to be drawn from is first cleaned
with a germ-killing solution.
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The medical technician or phlebotomist will wrap a flexible
band on the upper part of the arm to apply some pressure
to that area making the vein enlarge with blood. A needle is
then gently inserted into the vein.
Blood is collected into an attached vial or tube that is
airtight and the flexible band is then removed from the arm.
If multiple blood samples are to be taken, the phlebotomist
must be careful to follow the proper order of draw.
Finally, when the necessary blood is collected, the needle
will be removed and properly disposed of in a Sharps
container and the puncture site will be covered to stop the
bleeding.
Venipuncture Procedure
The venipuncture procedure is complex and requires both knowledge and skill. When drawing a blood specimen, the trained phlebotomist must
1). Prepare the accession order.
2). Identify the patient.
3). Verify patient’s diet restrictions, as appropriate.
4). Assemble necessary supplies and don gloves.
5). Reassure the patient.
6). Position the patient.
7). Verify paperwork and the selection of tubes.
8). Ensure the patient’s hand is closed.
9). Select the vein site.
10). Cleanse the venipuncture site.
11). Apply the tourniquet for no longer than 1 min.
12). Inspect the needle and other equipment.
13). Perform venipuncture using the correct order of draw.
14). Release and remove the tourniquet.
15). Ensure the patient’s hand is open.
16). Place the gauze pad over the puncture site.
17). Remove the needle.
18). Bandage the patient’s arm.
19). Fill the tubes (if syringe and needle are used); using the correct order of draw.
20). Dispose of the puncturing unit.
21). Label the tubes and record the time of collection.
22). Chill the specimen (if required).
23). Send properly labeled blood collection tubes to the appropriate laboratories
Venipuncture procedure video
Venipuncture Equipment
The equipment used during the venipuncture test can vary, but the
following are most commonly used for routine venipuncture:
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Collection tubes
Needles
Tourniquet
Wipes/Swabs
Gauze
Bandages
Gloves
Disposal unit
Venipuncture Sites
Phlebotomists may choose to draw blood from several different sites of
the body.
Most commonly, venipuncture will be performed on the Antecubital Fossa,
or the inside of the elbow. Here phlebotomists will typically choose from
three veins: the median cubital vein, the cephalic vein or the basilic vein.
If the tech is not comfortable with any of the veins in the inside elbow
area, they may choose a dorsal vein in the hand or, as a last resort, choose
a vein in the foot.
In some cases, a phlebotomist may have to switch sites if they find the
blood is not properly flowing from the vein.
Fear of Venipuncture
It is not uncommon for adults and children to feel some fear when having blood drawn,
which is why any discussion of venipuncture should at least bring this topic to focus.
Some individuals are afraid of needles, while others are frightened at the sight of blood.
When multiple vials of blood are collected it can seem like a large amount. However,
blood samples that are normally taken are actually very small. A typical single vial
contains about five milliliters, which is about one teaspoon. Even if several vials of blood
have to be drawn it usually amounts to no more than one ounce. Compared to the
standard blood donation which is about sixteen ounces, one ounce is really small.
Of course, the phlebotomist may understand this, however, the patient may not. This is
why a required skill for most phlebotomy jobs is to have excellent people skills with the
ability to keep the patient calm during the venipuncture procedure.
Other Types of Venipuncture
Venipuncture can also happen when patients have intravenous (IV) lines
started.
In most of these cases, the skin on the hand is pierced and a vein is
accessed so medications or fluids can be given intravenously. This type of
venipuncture procedure is a little different, and sometimes can be a little
more involved.
When there is an IV line present, blood can be drawn from this line. In other
words, there is no need for another venipuncture procedure.
IV lines are very useful in hospitals because some patients require frequent
blood tests.
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