Transcript Collection of blood

Blood Collection
Contact with patients
• The patient in a hospital is anxious (physical
condition), fearful, ill health, and he is physically
uncomfortable as a result of his disease or injury.
He is also separated from his family.
• The medical technologist must show the patient at
all time the kindness and understanding that can
mean so much
A child - terrible experience , remembered and
feared for the child for many years.
Gain the child trust before proceeding with blood
collection.
The child should be informed of what is going to
happen; if the child is told that the puncture will not
hurt the child trust will be lost because this
statement is generally is not true.
phlebotomy procedures:
• Blood specimens are commonly obtained from
patient's vein (Vein puncture). Under some
circumstances a skin puncture will be used for this
purpose. Irrespective of the method used certain
techniques are common to all phlebotomy procedures:
1. Check the request form:
2. The correct patient identification:
3. The correct specimen identification:
4. Safety and infection control
5. Preparation of the puncture site:
1- Check the request form:
• 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 sex.
▫ Requesting physician's complete name.
▫ Indicating the test(s) requested.
▫ 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.
2-The correct patient identification:
• Is critical for hospital patients this is accomplished by
checking the identification wrist band for the correct
name and hospital identification number.
• The procedure for out patient is not as easy. The
phlebotomist should ask the patient for his or her full
name and any other information specific for the
patient that can be verified by the requisition form.
3-The correct specimen identification:
• 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 hospital identification (ID) number.
▫ Date, time and initials of the phlebotomist must be
on the label of each tube.
4- Safety and infection control
• Because of contacts with sick patients and their
specimens, it is important to follow safety and
infection control procedures.
▫ Protect yourself
▫ Protect the others (your colleague, visitors,…)
▫ Protect the patient
Protect yourself
• Wear gloves and a lab coat or Change gloves after each patient or when
contaminated.
• Wash hands frequently.
• Dispose of items in appropriate containers.
• Dispose of needles immediately upon removal from the patient's vein. Do not
bend, break, recap, or recapped needles to avoid accidental needle puncture or
splashing of contents.
• Clean up any blood spills with a disinfectant such as freshly made 10% bleach.
• If you stick yourself with a contaminated needle:
▫ Remove your gloves and dispose of them properly.
▫ Squeeze puncture site to promote bleeding.
▫ Wash the area well with soap and water.
▫ Record the patient's name and ID number.
Protect the patient
• Place blood collection equipment away from
patients, especially children and psychiatric
patients.
• Practice hygiene for the patient's protection. When
wearing gloves, change them between each patient
and wash your hands frequently. Always wear a
clean lab coat or gown.
5- Preparation of the puncture site:
• The puncture site should be cleaned by rubbing
vigorously with a pad moistured with 70%
isopropanol. The area is the dried with sterile
gauze. Once the phlebotomy site has been cleaned
the decontaminated area should not be touched.
Micro sample technique
• Micro sampling refers to blood collection by skin puncture
and is frequently used in the following types of patients:
▫ Infants less than 6 months of age generally don’t have a large
blood supply, and it is dangerous to remove the volume of
blood involved in vein puncture.
▫ In young children: If only a small amount of blood is needed, a
skin puncture is performed on the finger.
▫ When an adult has poor veins, when the veins can't be used of
intravenous (IV) infusions, or in the case of a severely burned
patient the patient, the patient, the finger may be used as a
phlebotomy site.
• Reagent and equipment:
▫ 70% isopropyl alcohol.
▫ Sterile gauze pads - for application on the site from which the needle is
withdrawn.
▫ Gloves - can be made of latex, rubber, vinyl, etc.; worn to protect the patient and
the phlebotomist.
▫ Sterile disposable blood lancet
• Procedure:
▫ Follow the procedure as outlined above for greeting and identifying the patient.
As always, 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.
▫ Position the patient. The patient should sit in a chair, lie down or sit up in bed.
Hyperextend the patient's arm.
Location of the puncture site:
• The best locations for finger sticks are the 3rd and 4th fingers
of the non-dominant hand. Do not use the tip of the finger
or the center of the finger. Avoid the side of the finger
where there is less soft tissue, where vessels and nerves are
located, and where the bone is closer to the surface. The
2nd (index) finger tends to have thicker. The fifth finger
tends to have less soft tissue overlying the bone. Avoid
puncturing a finger that is cold or cyanotic, swollen,
scarred, or covered with a rash.
• When obtaining blood from infants less than 1 year of
age, blood is generally obtained from the heel of the
foot. The site chosen should be on the inside (medial)
or the outside (planter surface) of the foot. An
imaginary line may be drawn from the middle of the
large toe to the heel, and a line from between the
fourth and the fifth toes of the heel. The area outside of
these two lines is acceptable for puncture.
The puncture depth:
• For finger stick, the puncture should be no deeper than 3.1 mm because
the distance between the skin surface and bone will vary from 3.1 to
10.9 mm. The distance to the bone is only 1.5 to 2.4 mm in infants 6
months old, so the finger is not used in this age group of infants unless
special devices are used.
• For the heal puncture The depth of the puncture at any time must not
be more than 2.4 mm in order to avoid damage to the bone. Because the
blood supply for the infant's heal is located between 0.35 and 1.6mm
below the surface of the skin, the puncture need not to be any deeper
than 1.6 mm.
Performance of a skin puncture:
• The puncture site should not be cold; otherwise it must
be warmed either by rubbing the site, hanging the
hand or applying hot gauze on the puncture site.
• Using a sterile lancet, make a strong, fast and deep
skin puncture just off the center of the finger pad. The
puncture should be made perpendicular to the ridges
of the fingerprint so that the drop of blood does not
run down the ridges.
• Wipe away the first drop of blood, which tends to contain
excess tissue fluid. Collect drops of blood into the collection
device by gently massaging the finger. Avoid excessive
pressure that may squeeze tissue fluid into the drop of
blood.
• Have the patient hold a small gauze pad over the puncture
site for a couple of minutes to stop the bleeding.
• Dispose of contaminated materials/supplies in designated
containers.
• Label all appropriate tubes at the patient bedside.
• Deliver specimens promptly to the laboratory.
Discussion
• Blood from a skin puncture is a mixture of venous, arterial, and
capillary blood. The concentration of some constituents in the
blood will differ between skin puncture blood and an arterial or
venous specimen. Because of this, test reports should indicate if
the blood sample was obtained from a skin puncture.
• Excessive massaging or squeezing of the finger or foot will cause
tissue juice to mix with and dilute the blood. This will result in
erroneous and increased clotting of the blood.
• Since a deep puncture is not any more painful than a
superficial puncture, it is best to go deep enough the first
time thereby avoid puncturing the patient a second time.
• Excess crying will affect some test result (most notably, the
white blood cell count may increase considerably). It is
advisable to wait 30minutes to 1 hour following a crying
episode before obtaining the blood specimen.
• The thumb, big toe, and ear lob should not be used as a
skin-puncture site for phlebotomy.
• Misidentification of a patient is series error and can have
disastrous implication for the patient.
• Betadine (iodine) should not be used routinely to clean
the phlebotomy area because contamination with this
substance will cause some erroneous test results (falsely
elevated potassium, uric acid, and phosphorus results).
• Skin must be dried before puncture to avoid mixing of
blood with alcohol and hemolysis of blood, and to avoid
hemoconcentration.
Venipuncture
• A venipuncture must be performed with care. The veins of a patient are
the main source of blood for testing and the entry point for
medications, solutions, and blood transfusions. Because there are only
a limited number of easily accessible veins in a patient, it is important
that everything be done to preserve their good condition and
availability. Part of this responsibility lies with the medical
technologist. The ideal procedure is to have the patient lie down. If this
is not possible, the patient should sit in a sturdy, comfortable chair with
his or he arm firmly supported on a table or chair arm and easily
accessible to the technologist. A patient should never stand or sit on a
high stool during any process of blood collection.
• Reagent and equipment:
▫ Tourniquet.
▫ Alcohol Wipes - 70% isopropyl alcohol.
▫ Gauze sponges - for application on the site from which the
needle is withdrawn.
▫ Adhesive bandages / tape - protects the venipuncture site after
collection.
▫ Gloves - can be made of latex, rubber, vinyl, etc.; worn to
protect the patient and the phlebotomist.
▫ Sterile disposable syringes, the choice of a syringe are
governed by the amount of blood required
▫ Sterile, disposable needle. The choice of needle depends on the
size of the vein. The most commonly used needles are 20, 21,
and 22 gauge. The higher the gauge number, the smaller the
inner diameter (bore) of the needle. The length of the needle
also chosen according to the depth of the vein, the most
commonly used depth is 1.5 inch
• For vaccutainer system:
▫ 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.
▫ Needle disposal unit - needles should NEVER be broken, bent,
or recapped. Needles should be placed in a proper disposal
unit IMMEDIATELY after their use.
Procedure:
• Procedure for vein selection
• Although the larger and fuller median cubital and cephalic
veins of the arm are used most frequently, wrist and hand
veins are also acceptable for venipuncture.
• Palpate and trace the path of veins with the index finger.
Arteries pulsate, are most elastic, and have a thick wall.
• 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.
• Prepare the blood collection assembly, the needle is firmly adjusted to the tip of
the syringe, a check is then made to see that the plunger is not stick with the
barrel.
• Position the patient. The patient should 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.
• The patient should make a fist without pumping the hand.
• Select the venipuncture site.
• Prepare the patient's arm using alcohol swab 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. The needle should be in the
bevel up position (needle opening facing upward).
• 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.
• Deliver specimens promptly to the laboratory.
Discussion:
• There are certain areas are to be avoided when choosing a site of vein
puncture:
▫ 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.
Hematoma
• forms under the skin adjacent to the
puncture site - release the tourniquet
immediately and withdraw the needle.
Apply firm pressure.
• Causes of hematoma:
▫ The needle may have gone through the
vein.
▫ Remove the needle before removing the
tourniquet.
▫ The needle may not fully penetrate the
upper most wall of the vein. (Partial
penetration may allow blood to leak into
the soft tissue surrounding the vein by
way of the needle bevel). Failure to apply
pressure to the venipuncture site.
• To prevent hemolysis (which can interfere with
many tests):
▫ Mix tubes with anticoagulant additives gently 5-10 times
▫ Avoid drawing blood from a hematoma
▫ Avoid drawing the plunger back too forcefully, if using a
needle and syringe, and avoid frothing of the sample
▫ Make sure the venipuncture site is dry
▫ Avoid a probing, traumatic venipuncture
▫ Massaging, squeezing, or probing a site
• Prolonged tourniquet application (no more than 2
minutes) may cause:
▫ Hemoconcentration which is defined as increased
concentration of larger molecules and formed elements
in the blood of non-filterable elements (i.e. proteins).
▫ May lead to vein collapse.
▫ Tissue ischemia.
• Air must never be pumped into a vein because a few
cubic centimeters of air pumped into a vein could
cause death.
• Plunger of syringe must not be pulled pack with too
much force, to avoid hemolysis of blood, or the force
may pull the wall of the vein down on top of the bevel
of the needle causing the blood flow to stop.
• If an incomplete collection or no blood is obtained:
▫ Change the position of the needle. Move it forward (it
may not be in the lumen)
▫ Or move it backward (it may have penetrated too
far).
▫ Adjust the angle (the bevel may be against the vein
wall).
▫ Loosen the tourniquet. It may be obstructing blood
flow.
▫ Re-anchor the vein. Veins sometimes roll away from
the point of the needle and puncture site.
• If blood stops flowing into the tube:
▫ The vein may have collapsed; remove the
tourniquet to increase venous filling. If this is
not successful, remove the needle, take care of
the puncture site, and redraw.
▫ The needle may have pulled out of the vein. Hold
syringe firmly during drawing blood and keeping
the index finger alongside the hub and brancing
index on the patient arm.
Blood collecting tubes
• Several types of blood collecting tubes are available, which are
discriminated by their top color.
• We choose the suitable tube based on the test requested.
Thank you