Routine Hematology Tests

Question 0

control samples are run to assure the reliability of test results and can detect:
a. pre-analytical errors. b. wrong patient ID c. analytical errors. d. a partially clotted EDTA sample.

Answer 0

c. analytical errors

Question 1

What are some sources of error when it comes to blood collection?

Answer 1

wrong patient ID, partially clotted blood, hemolysis, hemodilution, hemoconcentration, wrong tube or insufficient fill.

Question 2

what is included in a CBC?

Answer 2

WBC, PLT, RBC and all the RBC components= hemoglobin, hematocrit, MCV, MCH, MCHC, RDW%

Question 3

how can you approximate the HgB and HCT from the RBC count?

Answer 3

rbc count x 3= hgb
hgb x 3= hct
(approximate)

Question 4

what is normal white count? normal HgB? normal PLT?

Answer 4

wbc = 4-11k/uL
HgB= 12-17g/dL
PLT= >150k/uL

Question 5

what is leukopenia? what is leukocytosis?

Answer 5

decreased wbc and increased wbc, respetively.

Question 6

What is Hgb? how is hemoglobin measured?

Answer 6

it tells us the amount of 02 being carried in the cells. it is measured photometrically. it is NOT the same as a Hgb test

Question 7

what is hematocrit?

Answer 7

percentage of red cells in a known volume of whole blood.

Question 8

what three tests parallel each other?

Answer 8

rbc, hgb, and hct. decrease and increase together.

Question 9

who has the highest hgb counts (men, women, newborns or children?)

Answer 9

newborns. then followed by men, children, and females.

Question 10

what does a decreased RBC, hgb, and hct mean?

Answer 10

anemia

Question 11

increased RBCs, HGB, and HCT means what?

Answer 11

polycythemia, due to increased production or fluid loss.

Question 12

What are RBC indices?

Answer 12

they define the size and or/hgb content of the red cells and include: 
MCV: mean cell volume
MCH: mean cell hemoglobin
MCHC: mean cell hemoglobin concentration
RDW: red cell destribution width

Question 13

What does MCV tell you?

Answer 13

it is hte avg. RBC size, and it varies with age. normal range for adults is 82-98 = normocytic. (newborn MCV= 110, children = 77)
MCV< 82 = microcytic
MCV > 98 = macrocytic

Question 14

What is MCH?

Answer 14

it varies with RBC size and Hgb content. Generally parallels changes in MCV

Question 15

What is the MCHC?

Answer 15

average hgb concentration per RBC. normal is around 30%. less than 30 indicates that cells may by hypochromic.

Question 16

what is the RDW?

Answer 16

index of RBC size and variation. you want it be low (around 10-14)%)–> this means all RBCs are about the same size. If it is high then you will expect variation in RBC size (called anisocytosis on report).

Question 17

what is anisocytosis?

Answer 17

high rdw (RBCs are varying in size)

Question 18

what is a signifcant RDW value?

Answer 18

> 22

Question 19

You should always compare the MCV value to what other value

Answer 19

RDW, because RDW can be elevated which throws off the other diagnositcs.

Question 20

what is the reference range for platelets?

Answer 20

150-450 thousand. decreased PLT count = thrombocytopenia (decrased production or increased desctruction). increased PLT = thromcytosis (increased production, post splenectomy). CRTICAL VALUES = LESS THAN 40,000 OR GREATER THAN 1 MILLION

Question 21

What must be done for all critical PLT counts/

Answer 21

they must be verified by microscopic exam. A major source of error is platelet clumping.

Question 22

What two types of differentials are there?

Answer 22

automated and manual. Manual should be done truly sick patients because it can also tell you morphology (as well as several other things, look at powerpoint slides)

Question 23

What is more reliable in the differential…the absolute number or the %?

Answer 23

the absolute number

Question 24

What is the number one cell type morphology in adults? children?

Answer 24

adults = neutrophils

children - lymph

Question 25

What cell type is ALWAYS abnormal?

Answer 25

-blasts.

Question 26

What is the reticulocyte count?

Answer 26

measures the rate of RBC production by the bone marrow. Retics appears as polychromasia on a Wright’s stained blood smear. must ORDER a retic count.

Question 27

What is the decreased retic count called? what about increased?

Answer 27

decreased = reticulocytopenia (decreased RBC production)
increased = reticulocytosis. (EPO stimulus, good indicator for hemolytic anemia!!)

Question 28

What is the ESR or sed rate?

Answer 28

it is a non-specific indicator or of disease. It is used to monitor patietns with chronic inflammatory disease process. ESR refers to the rate red cells settle as blood stands in a tube. in a normal person, sedimentation is SLOW. reported as distance the red cells fall in mm/time.

Question 29

ESR varies by…

Answer 29

age and sex. ESR gets faster as we get older.

Question 30

What is rouleaux?

Answer 30

under normal conditions, red cells do not form rouleaux (stacks of RBCs). High concentrations of certain plasma proteins promote rouleaux which increases ESR. Ex. fibrinogen.

Question 31

What acute phase reactant is responsible for an increased ESR

Answer 31

fibrinogen

Question 32

What is the significance of increased or abnormal ESR rates?

Answer 32

acute or chronic bacterial infections
chronic inflammatory diseases such as RA or SLE
malignances, tissue necrosis, MI, anemia, chronic disease.