02 - examination of blood and bone marrow hematology

7/23/2019 02 - Examination of Blood and Bone Marrow Hematology

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[email protected] || 1stsemester, AY 2011-2012

2 Examination of Blood and Bone Marrow Hematology

Hematology

Study of blood cells and coagulation

Encompasses analysis of blood cells

Concentration structure and function of

cells in the peripheral blood

Precursors in the bone marrow

Chemical constituent of plasma or serum

General Characteristics of Blood

Quantity

Varies with each individual, but the mean average in

the adult approximates 8% of the body weight (or

around 1/13 of the total body weight) or 5 to 6 liters

of blood or roughly estimated at 75cc/kg body weight

Color

Is due to the presence of hemoglobin in the RBCs

Arterial blood Bright red Oxyhemoglobin

Venous Purplish red Reduced

hemoglobin

Coal gas poisoning Bright cherry red Carbon monoxide

-hemoglobin

Potassium chlorate

poisoning

Chocolate Methemoglobin

Reaction

Blood is slightly alkaline, having a pH of 7.4 to 7.45.

This alkalinity remains constant throughout life.

Specific Gravity

Ranges from 1.075. It slightly varies with sex, being

higher in males than females. In pathological

condition, this is greatly altered.

Viscosity

Viscosity of blood approximates 5-6 times than of H2O

Tests used in hematological analysis

Blood

CBC Platelet count

Blood indices

Reticulocyte count

Bone Marrow Examination(Aspiration and Biopsy)

Marrow films

Direct films

Imprints

Crust preparations

Special staining methods

Romanowskys stain

Perls test for iron

Blood Analysis CBC examination

Hgb

Hct

RBC count

WBC differential count -

Platelet count infection

Blood indices

Peripheral smear

Reticulocyte count index of erythropoiesis

Bone Marrow Examination

Morphology of the cellular elements

(peripheral smear)

Cellularity of the bone marrow

Distribution of cells

Maturation of cells

Presence of rare cell types or abnormal cells

Interpretation

Cellularity of bone marrow

Numbers of megakaryocytes (platelet precursor)

Myeloid:Erythroid ratio

Cytologic or maturation abnormalities

Storage of iron and proportion of sideroblast

Indications

Microcytic anemia (iron deficiency anemia) Macrocytic anemia (megaloblastic anemia)VIt.

B12

Elevated reticulocytes (hemolytic anemia)

Neutropenia, thrombocytopenia and pancytopenia

aplastic anemia

Immunoglobulin abnormalities such as plasma cell

myeloma or macroglobulinemia

Hemoglobin

Main component of the red blood cell

A conjugated protein composed of 2 pairs of

polypeptide chains (globins) and 4 prosthetic heme

groups

Each gram of Hgb holds 1.34 ml of oxygen

The red cell mass of the adult contains approximately

600 grams of hemoglobin capable of carrying 800 ml

of oxygen

Complete Blood Count (CBC)

Sahlis Method (Hemoglobin Determination)

Principle: Conversion of Hgb to acid hematin by the

addition of 0.1 N Hcl

Normal Range Conventional = 12.0 16.0 g/dL

SI = 120-160 g/L

Indications

Anemia

Polycythemia

Cyanmethemoglobin (Hemoglobin Determination)

Principle: Ferricyanide oxidizes oxyhemoglobin and

cyanide converts methemoglobin to

cyanmethemoglobin

Measures all types of Hgb except sulf-Hgb

Normal range:

Convention: 120 160 g/dL

SI: 120 160 g/L

Hemoglobin Functions

Transport of oxygen from the lungs (high oxygen

tension) to the tissues (low oxygen tension)


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Types

Reduced Hgb

Hgb with iron unassociated with oxygen

Oxyhemoglobin

Hgb with iron associated with one molecule

of O

Methemoglobin Hgb with increased H1 in the erythrocytes

Sulf-hemoglobin

Mixture of oxidized partially denatured

forms of hgb that form during oxidative

hemolytic process

Oxidation of Hgb sulfur

Heme ring (Hgb) green

hemochrome denaturation and

precipitation of Hgb

(Heinz bodies)

Implications

Sulfhemoglobin cannot transport oxygen

but it can combine with carbon monoxide

to form carboxysulfhemoglobin

Methemoglobin and sulfhemoglobin cannot be

reduced back to hemoglobin and it will remain in the

cells until the cells breakdown

Erythrocyte Count

Principle : Blood is diluted with fluid that is isotonic

with erythrocytes

Formula

RBC count = # of cells

counted_____

Area x depth x dilution

factor

N.V.

Conventional: 4,500,000 6,000,000/cumm

SI: 4.5 X 6.0 X 1012

/L

Leucocyte Count

PRINCIPLE: Blood is diluted with a fluid that lyzes the

non-nucleated RBC but not the nucleated RBC

FORMULA

WBC count = # of cells

counted_____

Area x depth x dilution

factor

N.V.

Conventional: 4,500 10,000/cumm

SI: 4.5 X 10.0 X 109/L

RBC Morphology

Assessment of Red Blood Cell Morphology

1. Peripheral smear

2. Blood Indices

RBC MORPHOLOGY: Peripheral Smear

1. Size

2. Shape

3. Hemoglobin Content

4. Inclusions

5. Immaturity

Normal:

Size 6-8 um

Shape Biconcave disc; flexible and

deformable

Hemoglobin Content Central pallor - small

* Azurophilic granules

* Absent nuclei in erythrocytes and platelets

* Normal erythrocyte/platelet ratio 15-20:1 (helpful index for

recognition of thrombocytopenia and thrombocytosis)

Blood Indices

1. Size

2. Hemoglobin content

Changes in shape are more difficult to assess expertise

needed to have good knowledge of what constitutes normality

Allows classification of RBC as to size, hemoglobin content

and concentration1. MCV (Mean Corpuscular volume)

2. MCH (Mean Corpuscular Hgb)

3. MCHC (Mean Corpuscular Hgb Concentration)

Anemia

Reduction in the concentration of Hgb or Hct level in

the peripheral blood below the normal (lower limit of

95% of reference interval for individual age, sex and

geographical location [altitude])

Causes:

1. Impaired red cell production

2. Blood loss

3. Accelerated red cell destruction (hemolysis)

in excess of the ability of bone marrow to

replace these losses

Classification based on:

Mean corpuscular volume (MCV)

Is the average volume of individual RBC

Allows classification of cells into normocytic,

macrocytic and microcytic

MCV = __ HCT x_10__

RBCs (x 10

12

/L)

NV = 87 5 cu microns (fl)

(82 92 fL)

Mean corpuscular hemoglobin (MCH)

Is the amount of Hgb by weight in an average RBC

Allows classification of cells into normochromic,

hypochromic and hyperchromic

In newborn and macrocytic anemia

- MCH is high

In deficiency anemia,

- MCH is low

MCH = __Hgb gm% x 10__

RBCs (x 1012

/L)

NV = 27-31 ug (pg)

incorporation

oxidation


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Mean corpuscular hemoglobin concentration (MCHC)

Is the concentration of hemoglobin in an average RBC

If below normal, hypochromic

Higher than normal concentration are not possible as

normal RBC contains the maximum amount of Hgb

Normochromic, within normal MCHC

MCHC = __Hgb gm % x 100__

Hct

NV = 33-38%

No such thing as hyperchromacity (cannot be

secondary to high MCHC)for RBC membrane

abnormalities

Mean Corpuscular Hemoglobin (MCH) and

Mean Corpuscular Hemoglobin Concentration (MCHC)

MCH MCHC

Normochromic 27 31

pg

33

38%

Hypochromic < 27 pg < 33%

Hyperchromic > 31 pg > 38%

02 - examination of blood and bone marrow hematology

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