Finals Flashcards
When are blood cultures ordered
when there is Fever of Unknown Origin (FUO)
LIst the 3 aims of blood culture
- Confirm the infectious etiology
- Identify the etiological agent
- Guide the antimicrobial therapy
a positive blood culture means what
there is bacteria in blood
a systemic infection is known as
sepsis
blood cultures should be requested when
bloodstream infection or sepsis is suspected
clinical symptoms in a patient that can lead to suspicious of bloodstream infection
- undetermined fever or chills
- severed local infections
- abnormally raised heart rate
- low or raised body temperature
- raised respiratory rate
yellow top
pediatric aerobic (1-3mLgree)
green top
adult aerobic (5-10mL)
orange top
anaerobic (5-10mL)
black top
mycobacteria (5-10mL)
silver
mycoplasma (3-5mL)
if using a winged blood collection set, which bottle should be filled
aerobic bottle
if using needle and syringe which bottle should be filled first
anaerobic bottle
under-filling can cause
false negative results
over-filling can cause
inaccurate results
most important part of blood culture
antiseptics
alternative collection procedure for small amounts of blood
capillary puncture
it is the usual collection procedure for infants and children under 2 years old
capillary puncture
used for bleeding times, ancillary blood glucose testing, and obese patients
capillary puncture
mixture of arterial blood, venous blood and tissue fluid
capillary blood
bladed instrument that either puncture or makes an incision in the skin to obtain capillary blood specimens for testing
Lancet
use to disinfect the area before incision
alcohol pads
plain tubes with no anticoagulant
blue capillary tubes
heparinized tubes
red capillary tubes
use to seal capillary tubes
sealing clay
small plastic tubes used to collect tiny amounts of blood obtained from capillary punctures
microtainer tubes
for whole blood hematology and lead determinations
K2EDTA
for plasma determinations in clinical chemistry
Litium Heparin
for plasma determinations in clinical chemistry
Lithium heparin and gel for plasma separation
for glucose determinations
NaFI/Na2 EDTA
for serum determinations in clinical chemistry
clot activator with gel for serum seperation
for serum determinations in clinical chemistry
no additive
order of draw for capillary puncture
- capillary blood gases
- blood smear
- EDTA tubes
- other anticoagulant tubes
- serum tubes
capillary puncture site for babies
planter surface of heel
depth of capillary puncture for babies
2mm
cause of hemolysis in capillary puncture for babies
- alcohol not completely dried
- finger or heel squeezed to vigorously
- blood was scraped off
- newborns have increased RBC fragility
defined as the time it takes for a standard wound to stop bleeding
bleeding time
duke’s BT
earlobe/fingertip
Ivy BT
- volar surface of arm with BP cuff of 40mm Hg
- pressure of BP cuff will vary with age
Template BT
- modification of Ivy
- uses a template or a commercial device
causes of Prolonged BT (bleeding time)
- thrombocytopenia
- qualitative platelet disorders
*blood vessel abnormality - drug therapy
a process of spinning down or separating the cells from liquid portion of blood
centrifugation
a laboratory device that is used for the separation of fluids, gas or liquid, based on density.
centrifuge
centrifugal force is expressed as
gravity
of the centrifuge vibrates and makes noises, this means that
the centrifuge is unbalanced
centrifuge must be calibrated with a
tachometer
centrifuge that is
* commonly used in labs
* can take up to 100 tubes
* slow speed (up to 4000 rpm)
small benchtop
centrifuge that is
* takes tubes of small volume (2mL)
* commonly used in biochemistry, molecular biology. and biological labs
* can generate forces up to ~15,000 x g
microcentrifuge
centrifuge that is
* normally refrigerated
* 15,000 - 20,000 rpm
* research applications
* differentiation separation of nucleus, mitochondrial, protein precipitate, large intact organelle, cellular debris, bulky protein aggregates
high speed centrifuges
centrifuge that is
* expensive!!
* requires special rotors
* 65,000 - 120,00 rpm
* balance is important
ultracentrifuge
centrifuge that is
* centrifugal fields of 3000 - 6000 x g
* efficient separation of coarse precipitate or whole cells
large-capacity preparative centrifuge
used for determination of volume fraction of erythrocytes in blood and also for separation of microblood and solutions
hematocrit centrifuge
a procedure of dividing or separating specimens into separate containers patient samples
aliquoting
if red cells were left in contact with serum or plasma, glucose will decrease and potassium can increase. This process is called what
glycolysis
greatest concerns of all laboratory workers
mixing up patient samples
the time take for blood to clot in a person
clotting time
advantages of lee and white method
- more accurate and standard method
- test can be run with control
disadvantage of lee and white method
- it is also a rough method
- there can be contamination of syringe or tube
normal clotting time for lee and white method
5-10 minutes
advantages of capillary tube method
can be performed when venous blood cannot be obtained
disadvantages of capillary tube method
- method is insensitive
- method is unreliable
what significance does high value time for clotting time have?
- hemophilia disorders
- congenital deficiencies in clotting factors
what significance does low value time for clotting time have?
- disseminated intravascular coagulation (DIC)
- thrombotic predisposition
normal value for clotting time
2-4 minutes
used to determine whether the ulnar artery can provide collateral circulation to the hand after the radial artery puncture
allen test
was originally developed by Edgar V. Allen in 1929
allen test
if allen test is negative, what should u do
use another site to select
portion of a larger whole
Aliquot
most laboratory specimens are centrifuged at
750 to 1000g for 15 minutes
excessive crying of infant can lead to
elevated leukocyte count
