PMLS2_LEC7 Flashcards
e is the method of
choice for collecting blood from infants and children younger than 2 years for the following reasons
Dermal/ Capillary/ Skin Puncture
REASONS for dermal puncture in infants and children younger than 2 years
● Locating superficial veins that are large enough to accept even a small-gauge needle is difficult
● Use of deep veins can be dangerous and may
cause complications, including cardiac arrest,
venous thrombosis, hemorrhage, damage to
surrounding tissue and organs, infection, and
reflex arteriospasm (which can result in
gangrene)
● Drawing excessive amounts of blood from
premature and small infants can rapidly cause
iatrogenic anemia (i.e, a 2-pound infant may
have a total blood volume of only 150 ml)
for pediatric patients, blood collection should be limited to (what percentage) of the total blood volume within a 24-hour period and to (what percentage) of the total blood volume over an 8-week period
1-5%;10%
how do you estimate an infant’s blood volume
You can estimate an infant’s blood volume by dividing the child’s weight in pounds by 2 to obtain the kilograms and then multiplying the kilograms by 100, this gives you the approximate total blood volume
It may not be possible to obtain a satisfactory specimen by dermal puncture from patients who are severely
dehydrated and who have poor peripheral circulation or swollen fingers.
You may not be able to use dermal puncture for certain tests because of the larger amount of blood sample required
Dermal puncture may be required in many adult
patients, including those who are:
● Burned or scarred
● Receiving chemotherapy and require frequent
tests and whose veins must be reserved for
therapy
● Likely to be thrombotic
● Geriatric or have very fragile veins
● Likely to have inaccessible veins
● Obese
● Apprehensive
● Receiving home glucose monitoring and POCT
what causes hemolysis in dermal puncture
Excessive squeezing of puncture site (milking)
Increased number of red blood cells (RBCs) and
increased RBC fragility in newborns
Residual alcohol at the site
Vigorous shaking of the micro-collection tubes after collection.
● Blood collected by dermal puncture comes from ___,___,___
● May contain small amounts of____
(tissue fluid from the spaces between the cells) and ____ (fluid within the cells)
capillaries, arterioles, and venules; interstitial fluid, intracellular fluid
Warming the site before specimen collection
increases blood flow as much as ____,
thereby producing a specimen that is very close to the composition of arterial blood.
sevenfold
The concentration of
____ is higher in capillary blood than in venous blood, and the concentration of ___, ___, ___ are lower.
glucose; potassium, glycoprotein and calcium
Dermal puncture supplies
● Automatic retractable safety skin puncture
devices
● Micro-collection containers
● 70% isopropyl alcohol pads
● Gauze pads
● Bandages
● Approved sharp’s container
● Glass slides
● Heel warmer
The Clinical and Laboratory Standards
Institute (CLSI) recommends that the incision depth should not exceed ___ in a device used to perform heel punctures
2mm
● To produce adequate blood flow, the depth of
the puncture is actually much less important
than the width of the incision.
● This is because the major vascular area of the skin is located at the dermal-subcutaneous
junction, which in a newborn is only ___ below the skin but can range to 3mm in a
large adult.
0.35 to 1.6 mm; 3mm
Incision widths vary from needle stabs to___. Sufficient blood flow should be obtained
from incision widths no larger than___.
2.5 mm
● Available in a full range of blades for collecting
specimens, using microhematocrit tubes, as well as microtainer blood collection tubes and needles to collect blood for single drop glucose testing
is designed to activate only when the blade
or needle is positioned and pressed against
the skin.
BD Microtainer Contact-Activated Lancet
Color coded heel puncture lancets made
specifically for premature infants, newborns, and
babies
BD QUICKHEEL LANCETS
● Provides a range of color-coded, fully
automated, single-use, retractable, disposable
devices of varying depths
● ____ and ____ devices are designed for heel and finger punctures,
respectively
INTERNATIONAL TECHNIDYNE CORPORATION; Tenderfoot, Tenderlett
● Tenderfoot devices are available for a range of
patients, from micro-preemies (___), to
preemies (___), to newborns (___) and toddlers (___)
blue; white; pink/blue; pink
Available in five versions with varying needle gauges and penetration depths
UNISTICK 3 SAFETY LANCETS
what unistick lancet should be used?
– pediatric patients
– for delicate skin
- for normal skin/
general use
– for tougher skin/larger specimens
– for low-flow heel stick and high flow finger stick
● Unistik 3 Gentle (30 gauge)
● Unistik 3 Comfort (28 gauge)
● Unistik 3 Normal (23 gauge)
● Unistik 3 Extra (21 gauge)
● Unistik 3 Dual (18 gauge)
device is available for
heel punctures on newborns
The Unistik Tiny Touch
are color coded, retractable lancets with
an ergonomically rounded design for a
comfortable grip, a rounded base for pinpoint precision, and simple activation by applying pressure on the puncture site.
Safety Lancet needle depths range from ___
GREINER BIO-ONE LANCELINO SAFETY LANCETS; 1.2 to
2.4mm
● The latest device designed to make blood
collection fast and painless is _____
● The device, which is about the size of a stethoscope
head, is secured on the skin of the patient’s upper
arm by an adhesive hydrogel.
Seventh Sense
Biosystem’s Touch Activated Phlebotomy
have largely replaced the large bore glass micropipettes.
Micro collection tubes or microtubes
____which are frequently referred to as ____, are small tubes used to collect approximately 50 to 75 µL of blood for the primary purpose of performing a microhematocrit test.
Capillary tubes; microhematocrit tubes
