UNIT 7- CAPILLARY PUNCTURE Flashcards
Making an incision in dermal layer of the skin
- uses a lancet to make a small incision into the capillary
bed of the skin to obtain a small volume of blood
specimen.
CAPILLARY PUNCTURE
sterile, sharp instruments
that are intended for
one-time use only. They are designed for use in making
cuts in the skin for finger or
heel puncture.
Lancet/Incision Device
produces a small hole in the skin by vaporizing water in the skin. This eliminates the
risk of sharp injury because
cauterizing the skin is not necessary.
Laser Lancets
There are 2 types
that are used in
capillary puncture:
finger puncture
lancet and heel
puncture lancet.
known as microtube, a
small plastic tube used to
hold blood specimens
collected in the capillary
puncture. It has markings on
the side that show the
minimum and maximum fill
levels and, occasionally,
comes with a narrow
capillary tube.
Microcollection Tubes
narrow bore
tubes that are
made of either
plastic or glass,
typically used for
hematocrit
determinations.
They can hold 50
to 75 pL and are
filled by capillary
action. One end is
sealed with
sealants made of
clay or plastic.
Microhematocrit tubes
and sealants
used for blood films for
hematology determinations.
Microscope slides
used to increase the blood flow seven-fold by warming the puncture site.
Warming Devices
special equipment used
for collecting capillary blood gas (CBG) specimens,
which contains CBG
collection tubes, stirrers,
magnets, and plastic caps.
Capillary Blood Gas Tubes
Special Equipment for capillary blood gas
equipment
Capillary Blood Gas Tubes, Stirrers, Plastic Cups, Magnets
is the bright red blood
found in the pulmonary
vein, left chamber of the
heart, and the arteries.
● It is the oxygenated blood
in the circulatory system.
ARTERIAL BLOOD
is the blood that travels
from the peripheral veins
passing through the venous
system then through the
right chamber of the heart.
● This is dark red in color
because it is
deoxygenated.
VENOUS BLOOD
is the preferred specimen
for infants, young children,
elderly patients, and
Patients with severe burns.
● It is extracted from the
venules and arterioles
found in the capillary bed.
CAPILLARY BLOOD
fills the spaces around the
cells, filtered from the blood
capillaries, and drained
away as lymph.
INTERSTITIAL FLUID
is found inside the cells. It facilitates the movement of fluid in the membrane and
blocks the entrance of
unwanted materials.
INTERCELLULAR FLUID
Alternative to venipuncture if properly collected
When small amount of blood is needed
Small amount of blood is needed in the test
INDICATIONS FOR CAPILLARY PUNCTURE
Available vein is fragile, must be saved for other
procedures such as chemotherapy, and not accessible
because of scars and burns
After several unsuccessful venipuncture and specimen for
the test can be collected by capillary puncture
Thrombotic or clot-forming tendencies
Apprehensive patient or has intense fear of needles
No accessible vein
Blood needed is for POCT (glucose monitoring)
TRUE
Why is capillary puncture preferred for blood collection for infants?
● Low blood volume amount collected may lead to anemia
(4mg of iron is lost for every 10 mL of blood removes)
● Large quantity remove can cause cardiac arrest (life
threatening if >10% of blood is removed)
● Venipuncture may be difficult in infants and may damage
veins and surrounding tissues
● Puncturing deep veins can cause hemorrhage, venous
thrombosis, infection,and gangrene
● Infants can be injured by the restraining method used
during venipuncture
● Preferred specimen for some tests such newborn
screening
Tests that cannot be collected by capillary puncture
ESR, Coagulations studies requiring plasma specimens, Blood culture, Tests that require large volume of serum or plasma
ORDER OF DRAW
- Blood gas specimens (CBGs)
- EDTA specimens
- Other additive specimens
- Serum specimens
READ CAPILLARY PUNCTURE STEPS
READ CAPILLARY PUNCTURE STEPS
Supported on firm surface
Hands extended, palm up
Finger Puncture
Baby in supine position
Foot lower than torso
Infant Heel Puncture
If the patient is a young child, he/she
should be placed on the lap of his/her
guardian.
TRUE
Measuring of oxygen, carbon dioxide and blood
pH
○ Warm site for 5-10 minutes prior to collection
○ Proper collection technique
■ Minimize exposure to air
■ Immediately cap both ends
■ Mix specimen
■ Place tube in ice
○ There should be NO AIR SPACE. It should be
filled entirely with blood
CBG
Need of serum samples and larger amount of
blood
○ Done in newborns
○ Heel puncture
○ Proper collection is crucial to accuracy of the
results
○ Quick collection to minimize light exposure
○ Collected on amber-colored microtainer; if not
available, just cover the tube to cover the light
○ Avoid hemolysis – we have to be very careful
Neonatal bilirubin collection
screening on all babies born
○ Performed on infants between 24 and 72 hours
postnatal
○ Mandated testing of newborns
■ Important to detect the presence of
genetic, metabolic, hormonal, and
functional disorders
■ Detection and early treatment
■ Inborn disorders that could be
detected: Phenylketonuria,
Hypothyroidism, Galactosemia, Cystic
fibrosis
Newborn/Neonatal Screening
is a blood test that is
used to check abnormalities in the blood cells.
A small drop of blood is placed near the frosted end of the
glass side. Another slide is used to spread the blood in a
thin film over the slide. It is then air-dried and stained.
Routine blood film/smear preparation
Thick blood smear preparation is used to determine if the
patient has malaria, which is diagnosed by its presence in
the peripheral blood smear.
TRUE
is recommended for infants and small children. The blood
samples are collected on the same site as routine
capillary puncture specimens.
Preferred: 2 Serum gel microtainers
■ Acceptable: 2 Red-top microtainers
■ Submission Container/Tube: Amber
vial (T192)
■ Specimen Volume: 0.5 mL5
■ Collection Instructions:
1. Serum gel microtainers
should be centrifuged
within 2 hours of collection.
2. Red-top microtainers
should be centrifuged and
aliquoted within 2 hours of
collection
Capillary blood gas specimen by heel puncture
collection is used to help determine any
liver disorder in infants. This is collected with a heel stick.
Neonatal bilirubin test
done 24 to 48 hours after the baby is born, in
which a few drops of blood are collected
through heel stick to determine disorders that are not apparent at birth and could lead to
disability or even death.
Newborn screening blood spot collection
