Module 5 Flashcards
Compounds added to biological specimens to prevent them from clotting or to preserve
the constituents of a specimen.
additives
Any substance that prevents blood from clotting
anticoagulant
A prenatal test to detect birth defects that is performed at an early stage of pregnancy
and involves retrieval and examination of tissue from the organ.
chorionic villi sampling
The sequential process by which the multiple coagulation factors of blood interact in the
coagulation cascade, resulting in formation of an insoluble fibrin clot.
coagulation or clotting
Variation that occurs in the amount of a substance during a 24-hour period.
diurnal variation
Disruption of the red cell membrane causing release of hemoglobin and other components of red blood cells.
hemolysis
Disruption of the red cell membrane causing release of hemoglobin and other components of red blood cells.
hemolysis
The individual drawing a specimen of blood.
phlebotomist
The puncture of a blood vessel to collect blood.
phlebotomy
Factors that affect specimens before tests are performed and that can lead to error if not controlled; they are classified as controllable or uncontrollable.
pre-analytical factors
A substance or preparation added to a specimen to prevent changes in the constituents
of a specimen.
preservatives
The non-cellular component of anticoagulated whole blood; plasma contains clotting factors.
plasma
The watery portion of blood that remains after coagulation has occurred and can be obtained after centrifugation
serum
Collection of capillary blood usually from a pediatric patient by making a thin cut in the
skin, usually at the heel of the foot.
skin puncture
Obstruction of the return of venous blood to the heart and distention of the veins; in phlebotomy, this is a temporary blockage caused by application of pressure, usually from
a tourniquet.
venous occlusion
usually the specimen of choice
venous blood
Aside from venipuncture, blood samples can be collected using a skin puncture technique that can be done on
heel stick
middle or fourth finger
earlobe
uses both the liquid portion of the blood called plasma and the cellular components
whole blood
cellular components of blood
RBC
WBC
platelets
type of whole blood that is oxygenated and have uniform composition throughout the body
arterial blood
arterial blood is used in measuring:
pH
arterial blood gas
why is syringe used in arterial blood collection instead of evacuated tubes
because of the pressure in the arteries
primary arterial sites
radial
brachial
femoral
primary arterial sites
radial
brachial
femoral
hazards of arterial collection
arterial pressure
difficulty in stopping bleeding
hematoma
disadvantages of arterial blood
technically difficult
more painful
not used for routine tests
advantages of arterial blood
blood gas analysis
best for respiratory function
high exygen content
consistency
samples are deoxygenated and have variable composition
venous blood
direct puncture to collect venous blood is often located in the
antecubital area
venous blood differs from arterial blood in the concentration of
chloride, glucose, pH, CO2, lactic acid, ammonia
advantages of venous blood
good indicator
easier to obtain
used most frequently
disavantages of venous blood
minor and serious complications
lack of accessible veins
fear of needles
content of capillary blood
arterial blood
venous blood
tissue fluid
Point-of-care testing is often performed using this
capillary blood
capillary blood has higher
glucose
capillary blood has lower
Ca, K, total protein concentrations
advantages of capillary blood
small amounte needed
simple and painless
can change sites
disadvantages of capillary blood
not all tests
can rupture blood cells
calcofied nodules may develop in site
percentage of blood that is plasma
55%
percentage of plasma that is water
92%
other components of plasma
7% proteins
1% mineral salts, sugar, fat, hormone, vitamins
serum is absent of
Factor I, V, VIII, XIII
1 5 8 13
how long does blood clot with thrombin
5 minutes
how long does blood clot with clot activator
30 mins
how long does blood clot without clot activators
60 minutes
serum is centrifuged for
10 minutes 1000-2000 RCF
No interference from fibrinogen, anticoagulants and cations.
serum
Prone to fibrinogen, anticoagulant and cation interferences
plasma
Has a lower viscosity since it lacks fibrinogen
serum
Higher viscosity
plasma
Lower volume yield after centrifugation
serum
15-30% higher yield
plasma
Prone to interferences due to post centrifugal coagulation in serum
serum
No interference due to subsequent coagulation
plasma
Time consuming
serum
Time saving
plasma
fibrinogen interferes with
protein electoprophoresis
offers slight advantage in analysis of immunoglobulins due to improved specimen delivery and decreased precipotates
serum
next most common fluid for determination in the clinical chemistry laboratory.
urine
urine sample is more advantageous as
24-hour sample
CSF can be used for
protein and sugar determinatiolactate and other enzymes
capillary blood contains a higher portion of ____ because ____
arterial blood
pressure
capillary blood becomes even more similar to arterial blood in composition when the area is ____ because ___
warmed
increases blood flow in the area
higher in capilllary blood than in venous blood
glucose
lower in capillary blood than in venous blood
Ca, K, total protein
in infants, what is lost for every 10 mL of blood
4 mg of iron
life is threatened if more than ____ is removed at once
10% of patient’s blood
The behavior of a healthcare provider toward, or as perceived by a patient
bedside manner
In general, specimens for determining the concentration of body constituents should be collected when the patient is in a
basal state
These are variables with short-lived effects that can be controlled or modified.
extrinsic or controllable variables
may occur due to prolonged application of tourniquet
hemoconcentration
hemoconcentration increases
protein, calcium, bilirubin, potassium
Serum and plasma show visual evidence of hemolysis when hemoglobin concentration exceeds
50 mg/dL
hemolysis increase or decrese
AST
increase
hemolysis increase or decresase
acid phosphatase
increase
hemolysis increase or decresase
lactate dehydrogenase
increase
hemolysis increase or decresase
potassium
increase
hemolysis increase or decresase
magnesium
increase
hemolysis increase or decresas
phosphate
increase
hemolysis increase or decresase
LDH
increase
hemolysis increase or decresase
sodium
decrease
hemolysis increase or decresase
calcium
decrease
hemoglobin absorbance peaks occur at
417 nm
540 nm
575 nm
415 nm absorbs l8ghte very strongly
free hemoglobin with its pseudoperoxidase activity interferes in bilirubin determination by
inhibiting the diazonium color formation
this causes biliribin to
inhibitory effect
decrease
cortisol must be collected around
6-8 am
supine to upright position causes
hemoconcentration
If the patient is from a supine position then shifts to an inclined position (seated), allow the patient to at least be seated for ___ before specimen collection
20 minutes
ereft to supine position may cause
hemodilution
prolonged standinb increases concentration of
potassium
creatininen kinase
aldolase
prolonged standing decreases
plasma protein
lavender
EDTA
pink
EDTA
white
EDTA and gel
light blue
sodium citrate
red & gray
clot activator and gel
green
lithium heparin
light green
lithium heprin and gel
orange
thrombin
gray
potassium oxalate
sodium fluoride
tan
k2edta
royal blue
sodium heparin
yellow
SPS
sodium polyanethol sulfonate
black
sodium citrate
hematology
lavender
blood bank
pink
molecular diagnostics
white
coagulation studies
light blue
chemistry
green
chemistry lead tests
tan
chemistry trace elements and toxicology
royal blue
microbiology blood cultures
yellow
hematology erythrocyte sedimentation rates
black
