HAEMATOLOGY

Heamatology/Hematology is a department in the laboratory where bloods are studied, blood producing tissues and diseases of the blood.

PACKED CELL VOLUME

AIM: To know the ratio of red blood cell to plasma in a given volume of blood.

PRINCIPLE: The ratio of RBC to plasma is the packed cell volume (PCV), it used to determine the total percentage of red blood cell present in 100 percent total of blood. By rapidly centrifuging a given volume of blood, the RBC and other cells by virtue of their large mass will be packed at the bottom of the tube, leaving the plasma above, and its use to diagnose a patient with blood disorder such as ANAEMIA.

Anaemia is a disease condition that is associated with reduction of red blood cell. If the patient has a low level of PVC, such disease condition is called anaemia.

It has the following symptoms,

       1.  Dizziness

       2.  Headache, this is a result of low nutrients and distribution of        oxygen in the brain.

       3.   Body weakness due to low nutrient distribution in the body.

       4.   Loss of memory.

       5.   Pale skin.

MATERIALS 

1.  EDTA container
2. Blood sample
3. Micro haematocrit centrifuge
4. Micro haematocrit reader
5. Sterile lancet/syringe 
6. Swab (dry and wet)
7. Bunsen burner
8. Centrifuge tube
9.  Plasticine

PROCEDURE

1. Collect blood sample from patient after swabbing
2. Transfer the blood sample into EDTA container
3. Collect capillary tube and deep it into  the EDTA bottle containing the blood sample, the blood will flow into the capillary tube by capillary action.
4. Use Plasticine to seal the bottom of the tube
5. Open the centrifuge and place it inside and balance the weight with an empty tube, making sure they are directly opposite each other.
   

RESULT

The result is read at the level of the red blood cell and stop at the Buffy coat which separate the red blood cell from the plasma.

PCV result is based on locations and sex

Male: 40-52%

Female: 25-40%

Children: 50-62%

DISCUSSION

PCV result is based on location, sex and age. Those in high altitude always have higher PVC due to shortage of oxygen so more of the red blood cells are produced. 

Sex: females always have love PVC because of their monthly cycle.

Age: Children always have higher PCV because of their inactive liver at that age.

CONCLUSION

Patient that is short of blood (anaemia) should eat food rich in vitamins and other blood giving food. For the polycytemia, patient with excess blood should go to donate to create space for the production of new ones.

ERYTHROCYTE SEDIMENTATION RATE (ESR)

Aim: To determine the rate of fall (sedimentation) of the red blood cells (RBC) in a given time.

Principle: When blood is out of the body in a tube with anticoagulant and the tube is made to stand perfectly, vertically undisturbed, the RBC by virtue of their size and mass and under the influence of gravity, slowly sediments to the bottom of the tube.

MATERIALS NEEDED

          1.   Sodium citrate solution

          2.   Wintergreen apparatus (wintergreen stand and tube)

          3.   Blood sample

          4.   EDTA container  

          5.  Timer

          6.  Syringe

          7.  Swab (dry and wet)

          8.  Tourniquet

PROCEDURE

About 4ml of blood is collected through the vein puncture from the patient after swabbing. The blood is dispensed into an EDTA container. Then the 4ml of the blood sample is mixed with 2ml of sodium citrate after mixing a capillary tube is placed in the mixture and allow to flow in through capillary action to the level that is marked zero on the wintergreen tube or a syringe is used to inject the mixture into the western green tube. Then allow to stand for 1 hour to sediment.

RESULT

 After 1 hour, the calibrated tube is read using the level of the red sediment, normal values of ESR by wintergreen method

Males: 3 to 7mm/hr

Females: 5 to 9mm/hr

Infants: 0 to 2mm/hr

DISCUSSION

 ESR is an indirect measure of the level of inflammation present in the body. It is used to identify if a patient is responding to treatment or not. A common cause of high ESR is anaemia.

CONCLUSION

ESR is a non-specific test because increase in ESR does not tell the doctor exactly where the inflammation is in the patient’s body. It is also important to know that ESR increases gradually as the age of an individual increases and it is higher in female than in males.

WHITE BLOOD CELL COUNT

Aim: To determine the presence and the number of different types of white blood cells like neutrophils, eosinophils and basophiles.

Principle: Romanosky stain

MATERIAL NEEDED

             Microscope

             Blood sample

            Glass slides

        Leisman’s stain 

            Neuber counting chamber 

            Capillary tube

            Sterile lancet

        Swab (dry and wet)

            Pasteur pipette

1          Applicator

PROCEDURE: 

After collecting the blood sample, make a thin film on a slide, put a drop of blood on a clean grease-free- free slide placed on a flat surface. Hold a second slide between your thumb and forefinger and place the edge at 90⁰ against the top of the slide that the drop of blood is. Bring the second slide down until it touches the slide holding the drop of blood. As soon as it touches it, the blood will distribute itself along the edge of the slide.

 Push the second slide along the surface of the slide (slide containing the blood) at angle 45⁰ drawing the blood across the surface ina thin even smear. The feathering of the blood is essential to the counting process and is the principal characteristics of a good blood smear.

Leave the film to air dry. Label the slide with hospital number at one end. Then flood the smear with leisman’s staining and allow staying for two minutes. Flood again with 2ml of water and allow staying for eight minutes. Thereafter wash with clean water and allow the stain to dry.

Place a drop of oil immersion on the thin area of the blood smear. Then view with the microscope using 100 magnification. Pressing the correct key on the cell counter for each type of cell identified.

NORMAL RANGE OF DIFFERENT WBC

leukocyte	percentage	Absolute value per ml
neutrophils	80 to 70	3000 to 6000
eosinophils	2 to 4	150 to 450
basophils	0 to 1	0 to 100
monocytes	2 to 6	200 to 600
lymphocytes	20 to 30	1500 to 2700

RESULT

If 20 lymphocytes are seen among the 100 cells, the differential count for lymphocyte is 20%. This is known as relative count to get the absolute count the 20% is multiplied by the total white blood cell count (TC)  is about 4000 to 1600 per mm of blood

DISCUSSION

White blood cells are produced in the bone marrow. They protect our body against infection and aid our immune system. Neutrophils can increase in response to bacteria infection or inflammatory disease. Decreased neutrophils level may also be the result of several infections. Eosinophils can increase to allergic disorders.

CONCLUSION

The presence of these white blood cells in the body indicates the presence of foreign materials in the body (infection). The presence of basophile indicates the presence of poison in the body.