LAB EXAM FINAL Flashcards by Jim connelly

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

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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

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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

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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

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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 %)

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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

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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

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How does a doctor use the reticulocyte count?

Measures effective erythropoiesis. Evlauate/Diagnose Anemia

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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

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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

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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

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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

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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)

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PT:

Rgts Used
Normal Range
System of Coagulation
Clinical Use

Throboplastin/Ca Cl Mix
10-14 sec
Extrinsic
Monitor Coumadin Therapy

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PTT
Rgts Used

Normal Range
System of Coagulation
Clinical Use

PTT
Platelet Substitute and CaCl
Less than 35 sec
Intrinsic System
Heparin Therapy

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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

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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

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Duke and Ivy method for bleeding time (site of puncture and normal values).

Duke-Ear, 1-3 Min

Ivy- Forearm, 1-7min

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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

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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

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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

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