LAB EXAM FINAL Flashcards
Matching RBC parameters with normal values - Hgb, Hct, MCH, MCHC, MCV
Hgb-12-17 Hct- 30-50 MCH-27-32 MCHC-32-36 MCV-80-97
Match the cells for which we did manual counts with their normal values. (Eos, Plts, Retics, RBC, & WBC)
Eos-150-300
Platelets: 150,000-400,000
Retics:0.5%-2%
RBC: Millions
Match the below with the dilution ratios we used for the manual counts Eos Plates Retics RBC WBC
Eos: 1:32 Platelets: 1:100 Retics: 1:2 RBC: 1:200 WBC: 1:20
What is the Principle of the sedimentation rate (ESR),
The two methods for measuring the ESR, and
the normal values for males and females
Principle: Measures the suspension stability of the red cells
Methods: Westgren and Wintrobe
Males: 0-15mm/hr
Females: 0-20mm/hr
Given the values for the RBC, Hgb, and Hct, calculate the RBC indices (MCV, MCH, MCHC).
MCV: mean corpuscular volume = average size of RBC (Hct/RBC in millions)x10
MCH: Mean corpuscular hemoglobin= Concentration (Hgb/RBC in millions)x10
MCHC: Average amount of Hgb in RBC (w/v)(Hgb/Hct) x100 (reported in %)
State the principle of the osmotic fragility test and be able to name a condition in which the
osmotic fragility is increased and one in which it is decreased
Principle: Red cells are exposed to decreasing concentration of sodium chloride to observe the point of complete hemolysis (make a graph of % hemolysis)
Decreased: Sickle cell anemia, thalassemia, liver disease
Increased: Hereditary Spherocytosis
Explain the principle of the tube solubility method for SCA screening.
Expose the red cells to a reducing agent and hemoglobin S in insoluble. Positive test is cloudy/turbid. Negative Test has no Hemoglobin S and is clear
How does a doctor use the reticulocyte count?
Measures effective erythropoiesis. Evlauate/Diagnose Anemia
State three reasons for performing a WBC differential
Count and classify 100 WBCs
Observe RBC morphology
Diagnose patients conditions
Monitor therapy
Picture of general health
Be able to show how you would calculate a total cell count (not a standard count) if you are given the dilution, the volume counted, and the number of cells counted
Number of cells counted (x) correction for dilution (x) correction for volume
Correction for dilution is the reciprocal of dilution 1:50= 50 (x) Correction for Volume is 1/Number of squares counted (x) volume of square
How could you vary the counting procedure if you had to count (manually) an extremely high WBC count?
Use a red cell pipette to make a 1:100 or 1:200 dilution
Name the most commonly used anticoagulant for blood specimens to be used for
coagulation testing and be able to tell how it works
Sodium citrate-binds calcium
Why do you need to perform coagulation testing within two hours after specimen Collection
The labile factor will start to decrease, clotting time will increase falsely.
After a delay-spin it down and refrigerate/freeze plasma (if machine broken) or redraw( if left out to long)
PT:
Rgts Used
Normal Range
System of Coagulation
Clinical Use
PT
Throboplastin/Ca Cl Mix
10-14 sec
Extrinsic
Monitor Coumadin Therapy
PTT
Rgts Used
Normal Range
System of Coagulation
Clinical Use
PTT Platelet Substitute and CaCl Less than 35 sec Intrinsic System Heparin Therapy
Compare the principle of the Fibrometer with that of the CoaDATA 2000
Fibrometer: when clot forms it completes circuit and truns off timer
CoaDATA200:change in optical density detects the clot
Name two functions of the automatic pipette and two functions of the probe arm of the Fibrometer (noise maker)
Automatic Pipette: dispense reagents and turns on timer
Probe Arm: holds the electrodes, mixes the reagents. And senses the clot
Duke and Ivy method for bleeding time (site of puncture and normal values).
Duke-Ear, 1-3 Min
Ivy- Forearm, 1-7min
Be able to list two tests that you think should be included in a screen for coagulation disorders and indicate why you chose each test (i.e. checks intrinsic factors, checks plts, etc.)
PT- check for extrinsic factor
PTT- checks for intrinsic factor
Bleeding Time- measures platelet function
If normal plasma fails to correct an abnormal PT and PTT, what is the best explanation for the results?
Circulating anticoagulant/ antibody to a clotting factor
What is the only factor that will give an (increase)TT?
Fibrinogen (Factor I)
Be able to name a test to measure Platelet function
Bleeding Time
Be able to name a test to measure Stage I of coagulation
PTT
Be able to name a test to measure Stage II of coagulation
PT
Be able to name a test to measure Fibrinolysis
FDP, D-Dimer
list the factors. absorbed plasma
I V VIII XI XII
1 5 8 11 12
list the factors. aged serum
II VII IX X XI XII
contains Vit K lacks labile factors
2 7 9 10 11 12
list the factors. labile factors
V VIII
5 8
list the factors Vitamin K dependent factors
II VII IX X
2 7 9 10
use of pt and ptt substitution test
narrow down possible coagulation factors that are deficient
why not perform a series of specific factor assays
expensive and time consuming
what are some possible sources of errors in coagulation testing
improper ratio of anticoagulant to blood
sit at room temp too long
expired reagents
hemolyzed specicimen
why should a dr order pre surgical coagulation screening test
if patient has low-normal range, bleeding out could occur(if never had surgery) could decrease to a critically low level.
normal 50-100%
surgery decreased 30-40%
decreased less than 30% can bleed out
why is it imprtant for a hospital to establish its own normal range for the pt and ptt and how would a dr utilize the information
each hospital uses different reagents, instruments, and has different pt population.
drs want pts to be 1.5-2.5 times normal range
if pt has an increased bleeding time what is diagnosis and how could you prove it
Factor VIII Von Willeebrands disease
prove with factor VIII assay or substitution test
what is the antidote for coumadin (Warfarin)
Vit K
what is the antidote for heparin
Protamine sulfate
What is the INR and how is it used in the lab
International Normalized Ratio
regulates/ compares PT done in different labs
what test did we do in the lab that are used primarily in the diagnoses of fibrinolysis
FDP, D-Dimer
Case studies Acute Lymphocytic Leukemia (ALL)
blast and lymph
Case History Acute monocytic Leukemia (AMol)
blast and mono
case studies Acute Myleocytic leukemia (AML)
blast and mature granulocytes
case studies Autoimmune hemolytic anemia (AIHA)
spherocytes
Case studies Chronic Lymphocytic leukemia CLL
small mature clumpy lymphs, older person, smudge cells
Case studies Chronic myelogenous leukemia CML
all stages of granulocytes, increases bands, a lot of cells in the bone marrow
case studies Hemophilia A
Male bleeding joints PTT increased absorbed plasma sex linked
Case studies Idiopathic thrombocytopenia purpura (ITP)
coag test normal
bleeding time increased
decreased platelets
case studies Infectious mono(IM)
15-35 yrs
atypicaL LYMPHS not found in bone marrow
atypical lymphs in lymphnodes and PBS
slight fever
Case studies Iron deficiency anemia (IDA)
MCV less than 80 MCH less than 32 no iron in bone marrow precursers/jagged edge hypochromic
case studies Sickle cell anemia (SCA)
genotype SS
Case studies Thalassemia MAJOR
microcytic hypochromic NRBCs Howell jolly bodies bone marrow Increased increased iron target cells and envelope cells
case studies Von Willebrands disease
Factor VIII deficient
PTT abnormal corrected
increased bleeding time
