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what is the purpose of a CBC?
- monitor blood and tissue
- monitor overall general wellbeing
what is the purpose of the microhematocrit determination?
measure packed red cell volume
In this test EDTA whole blood is centrifuged and total PCV is exprssed as a percentage of whole blood volume.
This layer of blood contains H2O, electrolytes, glucose, fats, proteins, gasses and clotting factors.
this is the layer where leukocytes and platelets are present.
buffy coat layer
this is the layer used to determine HCT known as the packed cell volume.
red blood cell layer
how full should you fill capillary tubes?
three fourths of the way
how long should microhematocrit samples be centrifuged for?
5 minutes at 14,500rpm
duplicates of microhematocrit should be within ____.
how do you report microhematocrit determination results?
- average the duplicate results
- report as a percentage
microhematocrit reference values
- adult male: 42-52%
- adult female: 37-47%
- infant child: 30-43%
- newborn: 53-65%
What are four conditions increased HCT can be seen in?
- high altitudes
what four conditions decreased HCT can be seen in?
- vitamin or mineral deficiency
what are six sources of error for microhematocrit determination?
- intersitial fluid
- incomplete sealing
- buffy coat
- force stop
The purpose of this test is to screen for anemia in conjunction with the HCT and RBC count.
what is the main component of RBC's?
this transports oxygen to and CO2 from body tissues.
all forms of circulating hemoglobin (except sulfhemoglobin) readily convert to ________.
what is the reagent that oxidizes Hgb to methemoglobin by potassium ferricyanide?
methemoglobin converts to ____________ in presence of potassium cyanide.
what is the machine used to perform a hemoglobin test?
hemoglobin normal reference values
- adult male: 14-17 g/dL
- adult female: 12-16 g/dL
- newborn: 17-23 g/dL
- infant: 9-14g/dL
decreased Hgb can be seen in what two conditons?
increased Hgb can be seen in what two conditons.
what are five sources of error in Hbg?
- drabkin's reagent in direct sunlight
- Hgb C and Hgb S
Why would Hgb C and Hgb S be sources of error in Hgb testing?
- yield turbid solution
- fail to lyse red cells
The purpose of this test is to detect leukopenia or leukocytosis and to monitor progress of diseases.
what is the methodology of a WBC count?
what are the three components of the diluent in an unopette?
- buffered ammonium oxalate
- sorensen's buffer
what is the purpose of buffered ammonium oxalate in an unopette?
- dilutes sample
- lyse RBC's
- perserves WBC's, Plt's, retics, and NRBCs
what is the purpose of sorensen's buffer in an unopette?
maintain pH of reagent
what is the purpose of thimerosal in an unopette?
acts as an antibacterial agent
what volume does the unopette capillary pipet hold?
What is the device used to perform a WBC and platelet count?
how many primary squares are there in a hemacytometer?
where do you perform an erythrocyte count in a hemacytometer?
four coner and center secondary squares of center primary squares
where do you perform a leukocyte count on a hemacytometer?
four corner primary squares
where do you perform a platelet count on a hemacytometer?
25 secondary squares of center primary square
what is the normal reference values for WBC count
- Adult: 4.8-10.8x103/mm3
- Newborn: 9.0-30.0x103/mm3
Leukopenia is seen in what four conditons?
Leukocytosis is seen in what five conditions?
to detect thrombocytosis and thrombocytopenia is the purpose of what test?
normal reference value for platelet count
thrombocytosis can be seen in what four condtions?
- myeloprliferative disorders
- acute blood loss
thrombocytopenia can be seen in what three condtions?
- decreased platelet production
- increased platelet destruction
- increased platelet sequestration
what does ESR stand for?
errythrocyte sedimentation rate
to detect a nonspecific response to acute and chronic infection, inflammation, and tissue necrosis or infarction is the purpose of what test?
what is the methodology for ESR?
what test measures the rate RBC's fall in diluted human plasma?
how long must the tube be allowed to stand in a vertical position undistuirbed in an ESR?
how do you report ESR results?
- read the distance from the top of the tube to the plasma-red cell interface
- report results using mm/hr as unit of measure
normal reference values for ESR
- Men: 0-15 mm/hr
- Women: 0-20 mm/hr
what type of ESR result would be seen in patients able to form rouleaux?
reading after ___ hours will falsely decrease ESR results.
what is the quality control for ESR.
currently none required
to determine the relative amount of effective erythopoiesis taking place in bone marrow is the purpose of what test?
what is the methodology for a reticulocyte count?
new methyline blue method
immature RBC's that still contain RNA and ribosomes are called what?
______ amounts of whole blood is incubated with new methylene blue for ___ minutes
how may RBC's will you count when performing a reticulocyte count?
how many discrete blue granules must be counted to call a RBC a reticulocyte?
normal reference values for reticulocyte count
- Adults: 0.5-2.0%
- Newborns: 2.5-6.0%
what are two conditions that increased retic counts may be seen?
what are two conditions that decreased retic counts may be seen in?
- aplastic anemia
- ineffective erythropoiesis
The purpose of __________ is to serve as a quality control mechanism to check RBC count, Hgb and Hct measurements
Average volume of RBC's in femtoliter (fL)
Mean Corpuscular Volume (MCV)
Average weight of Hgb in RBC's in picograms (pg)
mean corpuscular hemoglobin (MCH)
Average concentration of hemoglobin in each individual RBC in percent or grams/dL.
Mean Corpuscular Hemoglobin Concentration MCHC
A degree of cell size variation expressed in percent.
Red Cell Distribution Width (RDW)
formula for MCV
Formula for MCH
Formula for MCHC
formula for RDW
RDW=SD of MCV/mean MCV
normal reference value for MCV
normal reference value for MCH
normal reference value for MCHC
normal reference value for RDW
11.5 - 14.5%
How do you interpret results of MCV?
indicates size of RBC
What does MCH indicate?
Hgb content in RBC
what can a decreased MCH be seen in?
what can an increased MCH be seen in?
increased MCH can be seen in what?
what does MCHC indicate?
- concentration of Hgb in average RBC
- central pallor
what is the normal central pallor of a RBC?
2-3 microns in diameter
to provide additional information for the diagnosis of hematologic disorders in conjunction with the WBC, RBC and platelet counts is the purpose of what test?
What is the definition f a WBC differential?
the percentage of each type of WBC present in the blood
what are the components of a WBC differential?
- 100 WBC Diff
- WBC Morphology
- WBC estimate
- Platelet estimate
- RBC morphology
When scanning a blood smear under 10x what do you check?
- cell distribution
- platelet clumps
- abnormal looking cells
- rouleaux formation
When performing a WBC diff what do you check under 40x?
how do you perform a WBC estimate?
under 40x count the number of WBC's in ten fields and devide by 10
average WBC/HPF equates to how many estimated total WBC/mm3
- average WBC/HPF =Total WBC/mm3
- 2-4 = 4000-7000
- 4-6 = 7000-10000
- 6-10= 10000-13000
- 10-20 = 13000-18000
when performing RBC morphology what do you check?
- RBC inclusion
if there are more than 10 NRBC's in your peripheral blood smear what is the formula to correct the WBC count?
(WBC x 100)/(100+NRBC)
how would you report Megakaryocytic cells, smudge cells, or epithelial cells?
list and report as #/100 WBC
how is a platelet estimation performed on a WBC differential?
under oil immersion count all platelets in 10 fields and devide by 10.
how is a platelet estimation reported?
report as adequate, increased, decreased, or clumped
if platelet estimated differs from the automated count what should be checked?
- check feathered edge for platelet clumps
- check for platelet satelitism
WBC Diff normal reference values
- Segs: 40-80%
- Band: 0-10%
- Lymphs: 25-45%
- Mono: 0-10%
- Eosinophils: 0-7%
- Basophils: 0-2%
How are results reported for a WBC diff?
- report out each type of WBC in %
- annotate WBC morphology
- annotate RBC morphology
- annotate platelet estimation
Neutrophilia is seen in:
- Bacterial Infections
- Chronic myelogenous leukemia (CML)
Eosinophilia is seen in:
- Allergic reactions
- Parasitic infections
Basophilia is seen in:
- Immediate hypersensitivity reactions
Lymphocytosis is seen in:
- Viral infections
- Chronic Lymphocytic Leukemia
- infectious mononucleosis
monocytosis is seen in:
- monocytic leukemia
what three things does CSF provide the CNS?
- removal of metabolic waste
- cushion against trauma
total volume of CSF
- Adults: 140-170 ml
- Neonates: 10-60 ml
what five items is CSF examined for?
- WBC count
- RBC count
- WBC Differential
In CSF ________ in conjunction with a differential is useful in diagnosis of disease.
What type of stain is used for a CSF differential
how soon must a CSF differential be done
within one hour
CSF is collected in 3 plain sterile tubes. What is each tube used for?
- Tube 1 for chemistry & serology
- Tube 2 for microbiology
- Tube 3 hematology
between what vertebrae is a lumbar puncture performed?
- 3rd and 4th lumbar vertebrae
- 4th and 5th lumbar vertebrae
what type of stain is used to perform a cell count on CSF?
When performing a WBC count on CSF how where do you count the WBC's?
in all 9 primary squares on both sides of the hemacytometer
what is the formula to calculate the total WBC count in CSF?
- WBC Count= average # of cells counted x 1.1
- use mm3 as the unit of measurement
true or false
the same procedure is used in both the WBC count and RBC count in CSF
what is the formula to detect added WBC due to traumatic tap in CSF?
WBC added=(WBCblood x RBCcsf)/RBCblood
WBC added - CSF WBC count= true CSF WBC count
how do you report a CSF diff if <100 cells are counted?
report the number of each cell
normal reference values for CSF
- color: colorless
- appearance: clear
- WBC: 0-5mm3
- RBC: none seen
normal reference values for CSF Diff
- Lymphs: 70%
- Monos: 30%
- Segs: none to occasional
how can you tell if xanthochromia is the result of intracranial hemorrhage?
- blood is evenly distributed in all 3 tubes
- no blood clots
- CSF remains xanthochromic after centrifugation
How can you tell if xanthochromia is the result of a traumatic tap?
- Blood decreases from tube 1 thru 3
- blood clots are present
- RBC's form sediment when centrifuged
if CSF is clotted but no blood is present what does that indicate?
what are three causes of an increased WBC count in CSF?
- Bacterial infection
- viral infection
- fungal infection
What are three causes of increased neutrophils in CSF?
- bacterial meningitis
- early fungal and viral meningitis
- cerebral hemorrhage
what are two causes of increased lymphocytes in CSF?
- multible sclerosis
- all forms of meningitis
what are two causes of increased moncytes in CSF?
- all forms of meningitis
What are two causes of increased eosinophils in CSF?
- parasitic infection
what is a cause of a blast in CSF?
what are three results in CSF that require review?
- metastatic cancer cells
what type of body fluid contains hyaluronate?
what type of body fluid supplies nutrients to cartilage and acts as a lubricant for joints?
what type of anticoagulant should be used on synovial fluid for a cell count or differential?
EDTA or heparin
why do you use a plain sterile tube for the viscosity and crystal exam on synovial fluid?
because anticoagulants may crystalize and interfere with crystal ID
what type of mycroscopy should be used for synovial fluid crystal exam?
crystal exams must be run ASAP because of what two factors that affect crystal solubility in synovial fluid?
temperature and pH
what are the most common crystals seen in synovial fluid?
- monosodium urate (MSU)
- Calcium pyrophosphate dihydrate (CPPD)
what is the appearance of MSU crystals?
- needle shaped
- negative birefringence
how do CPPD crystals appear in polorized microscopy?
- rod or rhombod shaped
- positive birefringence
normal reference value for synovial fluid
- Color: pale yellow
- Appearance: clear
- WBC Count: 200-600/mm3
- RBC count: none
normal reference values for synovial fluid diff
- Monos: =/> 75%
- neutrophils: <25%
what are two causes of an increased cell count in synovial fluid?
what could cause an increased neutrophil in a synovial fluid diff
what could cause an increase in lymphocytes in synovial fluid?
why would inflammation cause a low viscosity in synovial fluid?
inflammatory cells release enzymes that degrade hyaluronate
what could cause the presence of MSU's in synovial fluid?
what could cause the presence of CPPD in synovial fluid?
what type of serous membrane lines cavity walls?
what type of serous membranes covers organs within a cavity?
The fluid between two serous membranes that is an ultrafiltrate of plasma is called what?
this type of serous fluid forms due to systemic disorders that result in a disruption of the balance in the regulation of fluid filtration and reabsorption.
this type of serous fluid forms due to conditions directly involving the membranes themselves and results from inflammatory process
what is the function of serous fluids?
lubricates the surfaces of the serous membranes
normal reference values for serous fluids
- color: pale yellow
- appearance: clear
- WBC count: <1000/mm3
- RBC count: none
what are the predominant cells in serous fluid?
mononuclears (monocytes, lymphocytes, mesothelial cells, macrophages)
on a serous fluid diff what percent of your cells should be neutrophils?
what could cause the following colors in serous fluid?
- Yellow white: inflammation
- red brown: hemorrhage
- yellow brown: bilirubin
- milky green: chylous fluid
what could cause an increased cell count in serous fluid?
what could cause an increase in neutrophils in serous fluid?