LC7 Flashcards
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 or skin puncture
sterile, sharp instruments that are intended for one-time use only
Lancet/Incision devices
for use in making cuts in the skin for finger or heel puncture
Lancet/Incision devices
produces a small hole in the skin by vaporizing water in the skin
Laser lancet
eliminates the risk of sharp injury because cauterizing the skin is not necessary
Laser lancet
2 types of capillary puncture
Finger puncture lancet, hell puncture lancet
small plastic tube used to hold blood specimen collected in the capillary puncture
Microcollection container
also referred as bullets for their size and shape
Microcollection container
narrow bore tubes which are used for hematocrit determinations
Microhematocrit tubes and sealants
volume of blood collected when using Microhematocrit tubes and sealants
50-75 microliters of blood
where are Microhematocrit tubes and sealants used
Manual hematocrit / Packed cell volume (PCV) determinations
Microhematocrit tubes and sealants
- Color
- Purpose
- Red - with heparin; directly used from capillary puncture
- Blue - plain; for collection of serum samples
used for blood films for hematology determinations
Microscope slides
used to increase blood flow seven-fold by warming the puncture site
Warming devices
Recommended time for warming device
3-5 mins
Temperature recommended for warming device
not < 42 C
used for collecting capillary blood gas specimen and contains CBG collection tubes, stirrers, magnet and plastic caps
Capillary blood gas (CBG equipment)
Proper method of using CBG
- Mixed through figure of 8
- Minimum time : 20 seconds
What is the mixture of a capillary blood specimen
mixture of different blood and fluids - arterial blood, venous blood, capillary blood, interstitial fluid, and intracellular fluid
bright red blood found in the pulmonary vein, left chamber of the heart and arteries
Arterial blood
blood that travels from the peripheral veins passing through the venous system then through the right chamber of the heart
Venous blood
preferred specimens for infants, young children, elderly patients and patients with severe burns
Capillary blood
fills the spaces around the cells, filtered from the blood capillaries, and drained away as lymph
Interstitial fluid
found inside the cells; facilitates the movement of fluid in the membrane and blocks the entrance of unwanted materials
Intracellular fluid
Capillary reference values
- Concentration of glucose - higher
- Concentration of TP, Ca and K - lower
Indications for capillary puncture
- Appropriate choice for adults and older children
- Veins are fragile and not accessible because of scars and burns
- Veins are reserved for another procedure
- Clotting tendencies
- Extreme fear of needles
- Veins will be used for glucose monitoring or oral glucose tolerance test (OGTT)
Indications for capillary puncture
- Appropriate choice for infants
- Health risks - anemia and cardiac arrest
- Requires only a small volume of blood
- Venipuncture - damage veins and tissues surrounding site
- Puncturing - hemorrhage, thrombosis, gangrene, and infection
- Risk of injury because of restraint
- Capillary blood is preferred
How many mg of iron is lost for every 10 mL of blood
4 mg
When is capillary puncture not used
- ESR (Erythrocyte Sedimentation Rate)
- Coagulation studies requiring plasma specimens
- Blood culture
- Tests that require large volume of serum or plasma
Order of Draw for Capillary Puncture
- Slides for PBS
- Blood gas specimens (CBGs)
- EDTA specimens
- Lithium Heparin, Lithium Heparin w gel separator
- Sodium Fluoride / Potassium Oxalate
- Serum - Clot Activator
- Serum - No additive
- Newborn Blood Spot Card
Position of patient during capillary puncture
- Finger puncture
- middle or ring finger
- supported on a firm surface
- arms extended
- palms facing up
Reason why thumb, index and pinky are not sites for capillary puncture
- Thumb, Index finger - calluses
- Pinky - tissue is thin
Position of patient during heel puncture
- Heel puncture
- supine position
- foot lower than his/her torso
Weight required for Heel-Prick and Finger-Prick
Heel Prick - 3-10kg
Finger Prick - <10kg
Site selection criteria
pink, normal in color, and warm
Sites to be avoided
- scars, cuts, bruises or rashes
- Cyanotic (bluish)
- Edematous (swollen)
- Infected : visible swelling
Puncture or Incision site for adults and children older than 1 year old
- palmar surface of distal, end segment of middle finger or ring finger of non-dominant hand
- center or fleshy portion of finger
- perpendicular tp the grooved in the whorls
Puncture/Incision site in infants <1 year old
- plantar surface of the heel; on the median or lateral edge
- 2.0 mm deep
Precautions on the risk of puncturing the bone
- Osteomyelitis - inflammation of bone marrow
- Osteochondritis - inflammation of bones and cartilage
usually done when specimen is for pH or blood gas specimen collection
Warming
Fingers used to grasp patient’s finger
nondominant thumb and index finger
Fingers used to grasp patient’s heel
encircle heel by wrapping index finger around arch and thumb around bottom
Fingers used to grasp patient’s heel
encircle heel by wrapping index finger around arch and thumb around bottom
Reason why first blood drop is wiped away
may be contaminated with excess tissue fluid
Collections prioritized to avoid clumping and clotting
- Collection of slides
- Platelet counts
- Hematology specimens
Special handling instructions
- Cooling of specimen in crushed ice for CBG
- Transport at body temperature
- Light protection for specimens with bilirubin
Capillary blood gas proper collection technique
- minimize exposure to air
- immediately cap both ends
- mix specimen
- place tube in ice
blood test used to check abnormalities in the blood cells
Routine blood film/smear preparation
used to determine if the patient has malaria which is diagnosed by its presence in the peripheral blood smear
Thick blood smear preparation
quick collection to minimize light exposure and is collected on amber-colored microtainer
Neonatal bilirubin collection
Why should hemolysis be avoided during neonatal bilirubin collection
Hemolysis cause bilirubin to increase
performed on infants between 24 to 72 hours
Newborn/Neonatal screening
determine any liver disorder in infants
Neonatal bilirubin collection
should be centrifuged within 2 hours of collection
Serum gel microtainers
should be centrifuged and aliquoted within 2 hours of collection
Red-top microtainers
inborn disorders that can be detected in Newborn/Neonatal Screening
Phenylketonuria, hypothyroidism, galactosemia, and cystic fibrosis
RA for newborn screening
RA 8892
used for Newborn/Neonatal screening
Newborn screening equipment
Length of lancets for adult patients
2.2 mm lancets
Length of lancets for pediatric and neonatal patients
should not go beyond 2.4 mm
Length of lancets for premature neonates
0.85 mm lancet
Recommended depth for finger prick
- child over 6 months and below 8 yrs old - 1.5 mm
- child over 8 yrs - 2.4 mm
used to perform a manual differential count
Peripheral Blood Film
determines the number, type, and characteristics of blood cells
Manual Differential Count
reason why blood films are collected first
avoid platelet clumping
Gold Standard Method
Malarial Smear
