BS MEDICAL TECHNOLOGY – BSMDT 1B
PRINCIPLES OF MEDICAL LABORATORY SCIENCE 1
LAB LESSON:
INTRODUCTION TO CAPILLARY BLOOD COLLECTION
REQUISITIONS
•
•
•
•
•
•
All blood collection procedures begins with a
request for a test from a physician.
The most important step in blood collection is
positive identification (ID) of the patient. This
is done by matching the information on the
requisition with, for inpatients, the
information on the patient’s id or band for
outpatient, the information provided by the
patient.
For outpatients the laboratory process the
physician’s request and generates a
requisition, a set of labels for collection tube
or both. Tests for outpatients may also arrive
in a paper requisition.
Procedure for inpatients arrive in the
laboratory through a computer system and no
paper requisition is generated. Only a set of
labels is printed.
The Phlebotomist uses the requisition or
labels to determine what type of sample to
collect from the patient.
Requisitions have the following information:
▪ Patient demographics
▪ If in-patient, hospital ID number and
room/bed number
▪ Name of requesting physician
▪ Test status (e.g. STAT, fasting)
▪ Name of test requested
WHAT SHOULD YOU DO UPON RECEIVING REQUSITIONS?
✓ Examine to make sure that each has all the
necessary information are listed in the
requisition.
✓ Check for duplicates.
✓ Prioritize the requisitions (stat, timed
collection, routine).
✓ Collect all the equipment you need for the
collections you will be performing.
PATIENT IDENTIFICATION
•
Correct identification of the patient is the
most important step in any blood collection
procedure.
•
•
•
•
When blood is collected from a wrong patient,
the test result from that blood will be
attributed to the wrong person.
NEVER take any shortcut in identifying your
patient.
Three most important identifiers are the
following:
✓ Patient’s Name
✓ Date of Birth
✓ Hospital issued ID number (inpatient)
Ask the patient to state his/her name. The
patient must state his/her name without any
prompting from you.
CAPILLARY BLOOD COLLECTION
•
•
Also called as dermal puncture or skin
puncture and is the usual collection for
infants. In adults, it is an alternative collection
procedure when minute amount of blood are
needed for testing or for patients whom
venipuncture is not advisable or possible.
The depth of puncture must be carefully
controlled to produce adequate flow while
avoiding contact with underlying bone.
REASONS FOR PERFORMING CAPILLARY BLOOD
COLLECTION
•
•
•
When venipuncture is not advisable or
impossible.
When newborn or infant are requested for
several laboratory tests (e.g., bilirubin,
newborn screening, cbc).
In point of care testing (e.g., ancillary blood
glucose).
PATIENTS WHOM CAPILLARY PUNCTURE MAY BE
CONSIDERED
•
•
•
•
•
Children, especially younger than age 2
Geriatric patient
Obese patients
Patients for whom only one blood test has
been ordered for which a dermal puncture is
appropriate
Patients requiring frequent blood test.
1
BS MEDICAL TECHNOLOGY – BSMDT 1B
PRINCIPLES OF MEDICAL LABORATORY SCIENCE 1
LAB LESSON:
INTRODUCTION TO CAPILLARY BLOOD COLLECTION
•
•
Patients undergoing frequent glucose
monitoring.
Patients with burn or scars over venipuncture
site.
REMEMBER
•
•
•
Not all laboratory tests can be performed on
capillary blood samples.
✓ Blood culture
✓ Routine coagulation tests
✓ ESR
Capillary blood samples may not be
appropriate for severely dehydrated patients
because test results may not be accurate.
Results of tests may also vary from a capillary
blood compared with a venous blood.
EQUIPMENTS FOR CAPILLARY BLOOD COLLECTION
•
•
•
Skin puncture devices
Microsample containers
✓ Microtainer tubes (750 ul of blood)
which can come either in plastic or
glass.
✓ Tubes are color coded by additive to
match the coding of evacuated
containers.
Additional Supplies
✓ Alcohol pads
✓ Gauze pads/cottons
✓ Warming devices that increase blood
circulation (e.g., warm bath towel
soaked in water).
•
•
•
CAPILLARY COLLECTION SITES FOR ADULTS AND
CHILDREN
•
•
•
•
•
Capillary collection should be performed in
warm, healthy skin that is free of scars, cuts,
bruises and rashes.
The site must be ac and have a good capillary
flow near the skin surface but there must be
enough clearance above the underlying bone
to prevent the lancet from accidentally
contracting it.
Avoid the skins that are damaged, callused,
scarred, infected, bruised and edematous.
FOR ADULTS AND CHILDREN OLDER THAN
ONE YEAR, dermal procedure are almost
performed on the fingertips of the nondominant hand. The best sites are the palmer
surface of the distal segments of the third
(middle) and fourth (ring) finger.
If fingers can’t be used, the big toe may be an
option, but you need to consult the policy of
your lab regarding this.
Earlobes are never used for dermal puncture.
DERMAL PUNCTURE IN ADULTS
•
•
The puncture should be made near the fleshy
center of chosen finger. Avoid the edge of the
fingers as the underlying bone is too close to
the surface.
The puncture should be made perpendicular
to (across) the ridge of the fingerprint which
lessens the flow of the blood.
CAPILLARY COLLECTION SITES FOR INFANTS
•
SITE COLLECTION
•
To minimize the risk of inflammation and
infection, the lancet should never penetrate
more than 3.0 mm.
For heel puncture, the maximum depth is 2.0
mm.
For premature babies, the recommended
depth is 0.65 to 0.85 mm.
•
•
For children younger than 1 year, there is too
little tissue available in any of the fingers. Zfor
this reason, dermal puncture is performed in
the heel.
Only the medial and lateral borders of t he
plantar (bottom) surface can be used.
For older infants the big toe may be used if
the heel is unacceptable. Beware that the heel
may be callused on young children who have
begun to walk.
2
BS MEDICAL TECHNOLOGY – BSMDT 1B
PRINCIPLES OF MEDICAL LABORATORY SCIENCE 1
LAB LESSON:
INTRODUCTION TO CAPILLARY BLOOD COLLECTION
STEPS IN CAPILLARY BLOOD COLLECTION
❖ STEP 1: GREET & IDENTIFY YOUR PATIENT
❖ STEP 1.1: AFTER DOCUMENTING ON THE
REQUISITION THAT YOU ARE PERFORMING
CAPILLARY COLLECTION, SANITIZE YOUR
HANDS AND PUT ON GLOVES.
❖ STEP 2: ASSEMBLE YOUR EQUIPMENT
✓ Use the patient’s age and the tests
charged to determine which type of
collection tube you will need and
what type of skin puncture device to
use and whether to use a warming
device.
❖ STEP 3: SELECT AND CLEAN THE SITE
✓ Warm the areas first if necessary.
✓ Use 70% isopropyl alcohol to clean
the site and allow it to dry completely.
✓ Massaging the finger proximal to the
puncture site can help increase the
blood flow to avoid hemolysis,
massage gently and do not squeeze.
❖ STEP 4: POSITION AND HOLD THE AREA
✓ Hold the finger or hand firmly, this
prevents it from moving during the
puncture and reassures the patient.
✓ Grab the patient’s finger with its
palmar facing up, holding it between
your thumb and index finger.
puncture to full depth and then fully
retracted.
✓ Dispose the blade immediately in an
appropriate collection container.
❖ STEP 6: PREPARE TO COLLECT THE SAMPLE
✓ Wipe away the first drop of blood with
a clean gauze pad to prevent
contaminating the sample with tissue
fluids.
✓ Keep the finger in a downward
position to help encourage the blood
flow.
✓ Apply and release firm pressure
proximal to the site to increase flow,
but avoid constant massaging as this
will cut off the flow and cause
hemolysis and introduce tissue fluids
back into the sample.
❖ STEP 7: WALA DI KO ALAM BILIS NG SLIDE EH
❖ STEP 8: COMPLETE THE PROCEDURE
✓ Apply pressure to the puncture site
using a clean gauze.
✓ Once bleeding has stopped, you can
bandage the site for older children
and adults. Do not use a bandage on
children younger than age 2, as they
may remove the bandage and choke
on it.
✓ Label the microsample containers.
✓ Don’t forget to thank the patient.
❖ STEP 5: MAKE THE PUNCTURE, AND DISPOSE
THE BLADE PROPERLY
✓ Align the device so the cut is made
across the fingerprint ridges or heel
lines.
✓ Puncture the skin slightly lateral to the
center of the finger so that the hand
can be tilted for easier blood flow in
the container.
✓ Do not lift the device immediately
after the puncture is complete, count
to two before lifting the device to
ensure that the blade has made the
3