Exam A Blakes Flashcards
What pertinent facts must be considered when trying to establish normal ranges for any clinical lab?
You must consider your patient’s age and the reference intervals you are measuring.
The age of the population you are dealing with and their gender
What is the main specimen being run on it, such as what anticoagulant is being used?
Time of collection
Venipuncture time and if a tourniquet is used, such as when you measuring lactic acid, make sure you leave the tourniquet off because it can inflate the values.
- Which parameters are measured directly on the automated cell counter in this hematology laboratory and how are they measured?
RBCs, WBC, Hemoglobin,
- Which parameters are calculated values?
MCV, MCH, MCHC, Hct,
- Calculate CBC indices when possible using given information.
MCV= HCT/RBC * 10
Hct= (MCV * RBC)/ 100
MCHC= Hgb/Hct* 100
MCH= Hgb/RBC* 10
- How does electrical impedance work as a means of automated cell counting?
Electrical impedance works by counting the cells by the resistance given off when they cross the cell aperture. A cell with an increase in resistance will have an increase in impedance.
- List 3 sites from which bone marrow aspirates can be obtained. (These sites may differ between adults & children.)
The proximal ends of the long bones
Vertebrae( 3rd)
iliac crest ( 1st preference Adults and children)
Tibia( neonates 4th proximal)
Sternum (2nd only adults)
- Name three findings used to verify that bone marrow has been obtained from an aspirate, rather than peripheral blood
Presence of immature cells
presence of fat
presence of bone spicules
- List the hemogram parameters and the significance of each.
The hemogram includes the RBC count, WBC count, the Plt count, the Hgb count
the MCH, MCHC, and MCV.
The RBC count will be lower in Sideroblastic anemia, IDA, Aplastic anemia, lead poisoning, some leukemias, and in thalassemia.
The WBC count will be low in certain infections and HIV, and burns.
The plt count will be low in splenomegaly conditions, in DIC, in aplastic anemia, in certain bone marrow cancers, in myelopathic anemias,
The MCV will be high in certain leukemias, in megaloblastic anemia, and in B12 and folate deficiencies.
- What action/s should be taken if the linearity on the analyzer were exceeded?
Run a dilution of 1:7
A differential should be run if a value is outside the linearity range for WBCs.
Except if a lymphocyte count is over 50%= albumin smear, differential
for Plts remove the clot and then rerun for distribution errors.
For RBCs= if you have a low RBC count and high hemoglobin, then you should use a heat bath and check for cold agglutinates; if you have an abnormal RBC count and there being counted as plts; then recollect in sodium citrate( blue tube and multiply by 1.1.
- Compare and contrast controls and calibrators, including their definition and proper usage
Calibrator; a material of known value used to standardize any analytical procedure and thereby determine the value of an unknown
used for verifications/ Validations
Controls a stable substance that contains one or more known constituents used to verify the accuracy and precision of a method
- used for runs; are used for lot-lot validations
- Define reference ranges for CBC parameters at your institution.
WBC= 0-400 K/ul
Hct= 0-75.0%
NRBCs=o-600/100nRBCs
Rets=0-30%
RBCs= 0-8.60m/uL
- What is the proper corrective action for: cold agglutinins, lipemia, out of range results?
If you have a low RBC count and high hemoglobin, then you should use a heat bath and check for cold agglutinates; if you have an abnormal RBC count and there being counted as plts, then recollect in sodium citrate( blue tube and multiply by 1.1 also with plt satellitosis.
If you have lipemia, you should automatically rerun with a dilution or you can do plasma replacement( on heme powerpoint)
If you have an out of range results( rerun with a dilution ( a 1:7 dilution)
Pa
- What criteria makes a specimen unacceptable for CBC analysis?
A mislabeled specimen without a request form, wrong tube with anticoagulant, wrong medical records number.
- Compare different cellular morphology and function of WBCs, RBCs, and platelets.
WBCs functions are to stop foreign invades in the body, you have phagocytes such as Macrophages( best) –> neutrophils(2nd)—> dendritic cells—> eosinophils—> basophils.
by mobility–> neutrophil( 1st)–> Macrophage—> then eosinophil—> basophil
- Compare the normal blood cell and hemoglobin proportions for adults, infants, and children.
Segs
% of segs in Newborns= 50-70%
% of segs in Children= 28-45%
% of segs in Adults= 50-70%
Bands%
15-35% in newborns (3-11)
0-5% in children (0-5)
0-5% in adults ( 2-6)
Eosinophils%
newborns: 0-5%
children: 0-8%
Adults: 0-5%
Basos%
newborns, children, and adutls= 0-1%
Lymphs%
lymph: 10-20 newborns, 35-65 children, 20-40 adults
- Explain the purpose of hematological testing, including CBC, ESR, Retic Counts, etc.
CBC is used to find the indices such as RBC, WBC, and hemoglobin that aid in identifying specific disease states.
ESR test
Used to find the inflammatory conditions in the body( RBCs fall because they overcome their repulsion forces called zeta potentials and form rouleaux; this then forces the RBCs to fall fastest down because they have a higher density.
An increase in ESR is caused by increased plasma proteins, an increase in plasma viscosity, and the presence of rouleaux.
A decrease in rouleaux is caused by an increase in whole blood viscosity and a decrease in plasma protein concentrations.
Whole blood collected in 0.5 mg/ml EDTA is specimen of choice
westergren reference ranges: males: 0-15mm/hr
females: 0-20mm/hr
What conditions are present with a decrease In ESR
Hypofibrinogenemia, CHF, polycythemia, RBC morphological abnormalities such as anisocytosis, pokilo, spherocytes, and MM/ WM.
Retic counts
are done when the cell is alive and uses a supravital stain called new methylene blue.
count retics in 1000 cell and then divide by 10
uses a miller disk to count
- Which CBC values are useful in predicting the peripheral blood picture and how are they interpreted?
The CBC values are useful in predicting the Peripheral blood picture are the Retic value, the MCV, then the MCH and MCHC.