Capillary Specimen/Capillary Puncture
drops of blood drawn for specimen testing
Lancet/Incision Device
Disposable single use device used to puncture or make an incision in the skin.
Microtubes or Bullets
Small tubes used to collect small amounts of blood
Warming Devices/ Heel Warmers
a commercially available device used to warm the site of capillary puncture. Towels or diapers can also be run under warm water to wrap the site prior to the capillary puncture.
Interstitial Fluid
fluid between the cells
Intracellular Fluid
Fluid within the cells
Cyanotic
Bluish in color from lack of oxygen
Edematous
swollen with fluid
Whorls
Spiral pattern of the fingertips
Calcaneus
heel bone
Plantar Surface
Bottom of the heel on the sole side
Posterior Curvature
back (rounded part on backside) of the heel
Neonate
Newborn
NBS (Newborn Screening)
State mandated testing of newborns for detecting genetic, hormonal or functional disorders
Phenylketonuria (PKU)
Genetic disorder characterized by the inability to metabolize phenylalanine
Capillary Order of Draw
BEOS:
-Blood Gasses
-EDTA
-Other additives (EXCEPT SODIUM CITRATE)
-Serum
EDTA tubes
are drawn before other tubes in capillary order of draw to reduce the effects of platelet clumping.
Sodium Citrate (Light blue coagulation tubes)
are NEVER drawn on capillary blood.
Capillary blood
is a mixture of arterial, venous, and capillary blood in addition to interstitial and intracellular fluid.
When a capillary site is warmed prior to a puncture, blood flow is increased to the site up to 7 times, increasing the amount of arterial blood at the site.
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When performing a capillary puncture, the 1st drop of blood must be wiped away to prevent contamination of excess tissue fluid and any residual isopropyl alcohol from the site.
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The end, or distal segment of the ring or middle finger is the preferred capillary puncture site for children one year and older.
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lateral plantar surface of the heel
is the only puncture site that can be used on infants- 1 year of age.
CLSI recommended depth of lancet insertion
for an infant heel stick is no more than 2mm deep in order to avoid puncturing the calcaneus, or heel bone.
calcaneus or heel bone of a premature infant may be as little as 2.4 mm deep at the lateral plantar surface and half that depth at the posterior curvature.
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heel bone
calcaneus
The thinnest area of a properly made blood smear is one cell thick and is called a
feather, as it resembles a feathered edge.