MIDTERM - laboratory evaluation part 2 Flashcards
conditions for microcytic
- MACROCYTIC ANEMIA
*disorder of iron metabolism
* Iron deficiency anemia
* Anemia of chronic disease
* Congenital hypochromic- microcytic
anemia w/ iron overload
Anemia with appropriate BM responses
- Acute posthemorrhagic anemia
- Hemolytic anemia
Anemia with Impaired Marrow Response
- Marrow Hypoplasia
- Aplastic Anemia
- Marrow infiltration
- Infiltration by malignant cells, myelofibrosis
- Decreased Erythropoietin Production
* Kidney and liver disease
* Endocrine deficiencies
* Malnutrition
* Anemia of chronic disease
Macrocytic Anemia ( MCV l00-150 fl)
- Cobalamin ( B12) Deficiency
- Decreased ingestion
- Competative Parasite
* Fish tapeworm infestation
- Folate Deficiency
* Decreased ingestion
* Lack of vegetable
* alcoholism
Measures the average concentration of Hb.
Mean Corpuscular Hgb Concentration
MCHC
most valuable in monitoring therapy for anemia
Mean Corpuscular Hgb Concentration
MCHC
Indicates the mean or average volume of a red cell
Mean Corpuscular Volume ( MCV
- Individual cell size is the best index for classifying anemias.
Mean Corpuscular Volume ( MCV
Index expresses the volume occupied by a single
erythrocyte and measures in cubic micrometers(
femtoliters) of the mean volume
Mean Corpuscular Volume ( MCV
Indicates whether the rbc size appears normal
,smaller than normal or larger than normal.
Mean Corpuscular Volume ( MCV
Decreased __ values signify that a unit volume of
packed RBCs contains less hb than normal
MCHC
Normal Value for mchc
: 32-36 g/dl
Hypochromic anemia (MCHC <30)
conditions
- Iron deficiency
- Microcytic anemia
- Chronic blood loss anemia
Interfering Factors of mch
- Hyperlipidemia falsely elevates the MCH
- high heparin concentration falsely elevates
MCH
degree of the anisocytosis
- Red cell size Distribution Width
(RDW)
Explanation of the test : Automated method of
measurement is helpful in investigation of some
hematologic disorders and in monitoring response to
therapy.
Red cell size Distribution Width
(RDW)
The __ is essentially an indication of the degree of
anisocytosis
RDW
Helpful in distinguishing uncomplicated
heterozygous thalassemia ( low MCV
rdw
- use to asses erythropoietic activity of the bone marrow
Reticulocyte
Count
- whole blood, anticoagulated with EDTA is stained with a
supravital stain such as new methylene blue or brilliant cresyl blue
Reticulocyte
Count
% Reticulocyte formula
of reticulocytes/1000 RBCs observed x 100
red cell generation
retics count
is the actual number of reticulocyte in 1 liter of whole
blood
Absolute Reticulocyte Count (ARC)
Absolute Reticulocyte Count (ARC) ref range
25-75 x 109/L
in specimen with a low Hct, the percentage of
reticulocytes maybe falsely elevated because whole
blood contains fewer RBCs.
Corrected Reticulocyte Count
A correction factor is used considering the average
normal Hct to be 45%
Corrected Reticulocyte Count
Corrected Reticulocyte Count ref range
Reference Range:
2-3%
signifies as well if bm will response in anemia
Reticulocyte Production Index
(RPI)
Increased Reticulocyte Count conditions
- Hemolytic anemia
- Lead poisoning
- Malaria
- Parasitic infections
- Blood intoxication
- Kala-azar
- Erythroblastic anemia
- Sickle cell anemia
- Relapsing fever
- Leukemia
- Splenic tumor
Decreased Reticulocyte
Count conditions
- Aplastic anemia
- Acute benzol poisoning
- Chronic infections
- Anaplastic crisis of hemolytic anemia
Physiologic Increase of Reticulocytes
- Pregnancy
- At birth
- Menstruation
refers to the speed of fall of the erythrocyte to settle
down from their plasma.
Erythrocyte Sedimentation Rate
useful in monitoring the course of an existing
inflammatory disease or differentiating between
similar diseases.
Erythrocyte Sedimentation Rate
2 ways of measurement of esr
- Measuring the length of fall from the top of the column of RBC in a specified period of time
- Determining the time required for the red cells to reach a specified point
Phases or Stages in ESR
Agglomeration Phase
Phase of Fast Settling
Final Phase of Packing
the agglomerates sink rapidly
- the rate of fall depends on size-
takes place for about 40 minutes
Phase of Fast Settling
initial rouleau formation
few cells sink under gravity but the majority from agglomerates of various sizes
takes place during firsrt 10 mns
agglomeration phase
Macromethods in esr
- Wintrobe-Landsberg Method
- Westergren Method
- Graphic and Cutler Method
- Linzenmeir Method
Micromethods
- Micro Landau Method
- Smith Method
- Hellige-Volmer Method or Crista Method
. plasma factors increasing esr
a. increased fibrinogen concentration
b. increased globulin concentration
c. cholesterol
Red cell factors increasing esr
a. macrocytes
b. anemia
c. hemolysis
. Plasma Factors decreasing esr
a. increased albumin
b. increased lecithin
c. defibrination
red cell factors decreasing esr
a. microcytosis
b. more red cells
c. spherocytosis
d. increased sickle cells and poikilocytes
extrinsic factors affecting esr
- long standing of blood since rbc tends to be spherical
- excess dry anticoagulant
- temperature below 20°C
- short sedimentation tube
- small bore of sedimentation tube
- more blood specimen
- presence of blood clots
- dirty glass wares
Westergren’s Method’s ref range
- Women : 0 – 20 mm/hr
Men : 0 – 15 mm / hr - Children : 0 – 10 mm /hr
Increased ESR conditions
- All collagen disease , SLE
- Infection , pneumonia
- Inflammatory disease
- Carcinoma , lymphoma
- Toxemia
- anemia
Methods of Preparation of Blood Smears
Manual Method
– Wedge/Push/2-Glass Slide Method- the simplest and most commonly used
the simplest and most commonly used manual method of smearing
Wedge/Push/2-Glass Slide Method
Advantages of manual method
a.slides are not easily broken
b.easy to prepare
c.easy to label and transport
d.allows storages, even without cover slip
e.abnormal cells can easily be foun
Characteristics of a Good Smear
- There should be a transition from thick to thin area.
- Smear should occupy ¾ of the length of the slide.
- Most have a smooth even surface, free from waves,
ridges and holes. - White blood cells should not be bunched at the end
or edge of smear. - It should have a feathery edge or tail.
Uses of Thin Smears
- WBC differential count
- Stained red cell examination
- Platelet count (indirect method)
- Reticulocyte count
- Siderocyte count
- Malarial parasite examination
- Thorough study of morphology of blood cells
Requirements to Produce a Proper Blood Films
- Use of a chemically clean glass slides
and cover glass. - Use of not too large nor too small drop
of blood. - Work is done quickly before coagulation
of the blood. - Proper angle and pressure of the
spreader.
Methods of Drying the Blood Films
- Air drying
- Heating in the oven for a low flame
- Chemical drying in ethyl alcohol
Fixatives
for Blood Films
Factors Affecting Thickness/Thinness of Smear
Factors - Size of the drop of blood used
a. large drop
b. small drop - Methanol
- Absolute Ethyl Alcohol
- Absolute Ethyl Alcohol and Ether
- 1% solution of HgCl₂
- 1% Formali
proper angle smear of smearing
35-45°
Pressure exerted when pushing the
spreader against the stationary slide
heavy pressure
thin smear
Speed of the spreader slide
too fast
thick smear
preferred for bone marrow preparation
Cover Glass/Ehrlich’s Method
even distribution of blood cells especially leukocytes is observed
Cover Glass/Ehrlich’s Method
Disadvantages of cover glass method
a. cover glasses are easily broken
b. require chemically clean coverglass
c. difficult to prepare
d. difficult to label, stain and transport
there is even distribution of cells but
yields limited blood smear.
Beacom’s Method/Cover Glass and Slide Method
Automated Method for smearing
Spun Smear
Smear Prepared in Miniprep
prepared in hemaspinner
Spun Smear
Staining of Blood Smears
Wright’s Stain
2.giemsa stain
3. May-Grunwald’s stain
4. Leishman’s stain
5. Jenner’s stain
6. Panoptic stain
7. supravital stain
combination of Romanowsky stain and another
stain
Panoptic stain
considered polychrome stain
Wright’s Stain
Wright’s Stain component
methylene blue
eosin
– basic dye and stains
acidic cellular components
methylene blue
acid dye and stains basic
(eosinophilic) cellular components
eosin
- buffer added to the stain
- must have a pH of 6.
Sodium Phosphate
it is the enumeration and determination of
relative proportion or percentage (%) of
each type of leukocyte in the peripheral or
venous blood.
Leukocyte Differential Count
Steps in Leukocyte Differential Count
- Preparation of blood smear
- Staining of blood smear
- Differentiation of leukocytes
- Reporting of results
Ways of Scanning Smears for Differential Count
- Strip or Horizontal Method
- Crenellation Method- cells are counted fro
- Exaggerated Battlement Method
- Two Field Meander Method
- Four Field Meander Method
all the cells in a longitudinal strip from
head to end or tail of the cells are
counted.
Strip or Horizontal Method
cells are counted from the upper part
of the smear, the lower part, then
sideways, then to the upper part until
100 cells are differentiated.
Crenellation Method
Shift to the left
- the presence of an increase in younger
forms of leukocytes
Shift to the left
seen in pyogenic infections
Shift to the right
-the presence of an increase in older forms
of leukocytes
Shift to the right
seen in megaloblastic anemia, pernicious
anemia, and in convalescence
