specimen collection ( capillary) Flashcards
“Proper patient identification is the first step in sample collection.”
SPECIMEN COLLECTION
- Prime factor in order to attain accurate results in the clinical laboratory is
patient identification
- Conscious Inpatients/Hospitalized patients
- Sleeping patients
- Unconscious
- Infants and Children and Mentally Incompetent
- Outpatient/Ambulatory patients
PATIENT IDENTIFICATION PROCEDURES
- Ask full name (verbally), confirm using ID
bracelets - All of your question should not be answerable
by yes or no. - Every patient admitted in the hospital has an ID
bracelet
Conscious Inpatients/Hospitalized patients
- Same as conscious, awakened before
collection - Awaken the patient. Ask their full name verbally
then confirm using ID bracelets.
Sleeping patients
- Ask relative or nurse or physician and
record name of person, ID bracelets - For coma and ICU patients, confirm details to their relative (first asked), nurse, or physician. Confirm ID Bracelet
Unconscious
Ask relative or nurse and record name of
person, ID bracelets
Infants and Children and Mentally Incompetent
- Receptionist verifies the ID of the patient
o The receptionist in the laboratory is the
first to interact with the patient. - Patient may show ID with picture
- Clinic issued ID card
- In case there is no verification from the
receptionist and no ID, make the patient state
full name, date of birth and spell the last
name
o Usually, 2 or 3 items for verification is
needed.
▪ Name, Date of Birth, Age, Address - Items for verification depends on the SOP of
the hospital
Outpatient/Ambulatory patients
Method for blood collection, for adult males:
5-6L of whole blood
Method for blood collection, For adult females
4-5L of whole blood
cells composed of 40-45%
(1.89L)
Plasma composed of 55-60%
(2.84L)
_____ only a fraction of the whole blood that is circulating in our body.
plasma and cellular components
made up of water, proteins, nutrients, hormones, and electrolytes
PLASMA
BUFFY COAT ( wbc and platelets )
PACKED RBC
CELLULAR COMPONENTS
TYPES OF BLOOD SPECIMENS
- serum
- plasma
- whole blood
_____ most common and the best specimen, but in case you want to decrease the turn-around-time and at
the same time for routine chem sometimes plasma is an
option
serum
used in clinical chemistry depending on the anticoagulant used
Plasma
- clear
- pale yellow in color
- plain tube
- clotted blood
- without fibrinogen
serum
- clear to slightly hazy
- pale yellow in color
- anticoagulated tube
- unclotted blood
- with fibrinogen
plasma
TYPES OF BIOLOGICAL SPECIMENS
- Saliva
- Urine
- Feces
- Synovial, Spinal, Amniotic, Pleural, Pericardial, Ascitic Fluid
- Various type of solid tissues
Blood Collection
o 3 methods
- Arterial Puncture (artery)
- Skin puncture (capillaries)
- Venipuncture (veins)
collect blood from the artery
- arterial puncture
collect blood from the capillaries
skin puncture
defined as the process of collecting blood, comes from the Greek word “phleb” means veins and “tomy” meaning
slice or cut.
Phlebotomy
- Not all artery in the body can
be used as a site for arterial
puncture - The usual artery that is used
for arterial puncture is the
brachial artery, radial artery
(preferred and common) and
femoral artery. - The angle for the collection is
45 or 90 degrees. - For infant or newborn, Scalp
and Umbilical artery
ARTERIAL PUNCTURE
- Blood is obtained/withdrawn from a patient’s artery
- Blood sample is collected without torniquet
ARTERIAL PUNCTURE
▪ pH measurement
▪ 𝑃𝐶𝑂2 level
▪ 𝑃𝑂2 level
▪ Bicarbonate level
Blood Gas Analysis
oxygenated blood with a bright red
color
Arterial blood
o test for collateral circulation
o important procedure performed before arterial puncture to know if there are other arteries to supply blood on that part of the body.
o Commonly used anticoagulant in arterial puncture is Heparin because it is the additive or anticoagulant that is best to use in collecting blood to be used for Blood Gas Analysis.
Allen’s test
to know the pH level, 𝑃𝑂2 level, and if the oxygenation of the patient is okay
o Uses either a glass syringe or plastic syringe
Arterial Blood Gas Analysis (ABGA)
- Produces good result
- Advantage is it is
reusable
Glass syringe
- Contamination is less
because it is a one-time
use - Allows more leakage
when collecting blood
Plastic Syringe
- Bright red color
- Obtained from artery
- Oxygenated
Arterial Blood
- Dark red color
- Obtained from vein
- unoxygenated
Venous Blood
5 SITES FOR ARTERIAL PUNCTURE
- radial artery
- brachial artery
- femoral artery
- scalp artery
- umbilical artery
Commonly used in newborn patients
Scalp Artery
Ideal site for arterial puncture in newborn
patients
Umbilical Artery
- Length of lancet:1.75 mm
- Depth of incision (depends on the patient)
o Infants and children: <2.0 mm
o Adults: <2.5 mm - Distance from skin surface to bone or cartilage: 1.5-2.4
mm
o Prevent contact with bones to avoid infection
Capillary Puncture or microsampling
When to use skin puncture, aka Capillary Puncture or microsampling
o Small amount of sample needed
o Repeated venipuncture resulting to severe vein damage
o Burn patient with bandage
- No accessible veins
- Fragile veins
- Thrombotic veins/ those with clot-forming tendencies
- POCT (point of care testing) samples
o Random Blood Sugar using glucometer - Newborns and infants
Indications for skin puncture
- Lateral plant heel surface
(newborn and infants <1) - Palmar surfaces of fingers
(3rd and 4th) - Plantar surface of the big toe
- Earlobes – least site
Preferred sites for skin puncture
- Central arch area of an infant’s heel
- Fingers of newborn or infant, 1 y.o.
- Thumb, index and 5th fingers
o Thumb has pulse
o Pinky finger has insufficient depth - Fingers on the side of mastectomy
- With scarred areas
o Bruises, edematous, cyanotic, calloused,
infected, recently punctured
Sites not recommended or should be avoided
collects blood from the capillary, the blood that is collected is a mixture of arterial and venous blood along with
interstitial and intracellular fluid.
Between the arterial and venous, it is more of the arterial blood. Mixture of oxygenated and
deoxygenated blood.
Skin puncture
Patient tends to develop iatrogenic anemia, also known as hospital induced anemia. Anemia acquired due to repeated blood collection
Disadvantage of performing skin puncture
person who can benefit with skin puncture
- Pediatric children
- Obese patients
- Chemotherapeutic patients
- burn patients
- adult patients
- EDTA > Other additive tubes > Serum tubes
o Example: purple, green, red
Order of filling microsampling
- Hold finger between your index finger and thumb
- Puncture the finger using a quick, smooth motion
- Wipe away the first drop of blood (contains alcohol and interstitial fluid)
- Collect sample
Skin puncture procedure:
- BGA of newborn and infants, measuring pH and 𝑝𝐶𝑂2 but not 𝑝𝑂2
- Preferred site: Earlobe
- Commonly used site: Lateral plantar heel surface
- Massage or apply warm compress on the site of puncture to enhance blood circulation.
o Heel warmer or warm towels
Arterialized Capillary Blood
a parameter of BGA that determines how
much oxygen is present or the partial pressure of the oxygen present.
▪ Cannot accurately measure this as
there is deoxygenated blood in the
sample
𝑝𝑂2
- Warm the earlobe or heel surface with paper towel
saturated with warm water (39-45⁰C). - Flick the earlobe with the index finger.
- Cleans the area with 70% alcohol.
- 2 Heparinized tubes are placed in the center of next drop
of blood and filled capacity without air bubbles. - Both ends are sealed in clay after the insertion of flea.
o flea- small metal bar used to stir blood inside - Blood is stirred using a magnet.
Arterialized Capillary Blood Procedure
o Arterial blood pressure is <95mmHg
(hypotensive)
o Area has poor blood supply
o Patient has decreased cardiac output
o Patient with vasoconstriction
Capillary arterialization should not be done
minute metal filling that help mix the specimen while the blood is entering the tube
- moves the blood for a homogenous mixture
Flea
best site for BGA for new
born
Indwelling umbilical artery
- Choose puncture site.
- Cleanse the area with 70% alcohol.
- Puncture across the finger line and wipe the first drop of blood that could contain interstitial fluid that could affect the
result. - Collect blood using the capillary tube through capillary action. Prevent performing milking of the site
SKIN PUNCTURE PROCEDURE
