Practicals performed in 3rd year mbbs. Undergraduate level. CBC, Peripheral smear, DLC, Coagulation tests

1. Blood Module Practicals

2. Practicals
• CBC
• Peripheral Smear in Anemias
• DLC
• Coagulation Tests (pt, apt and bt/ct)

3. Complete Blood Picture
• The CBC measures the levels of the three basic blood cells: red blood
cells, white blood cells, and platelets.
• Complete Blood Counts (CBC) form the main bulk of laboratory tests
requested.
• It includes the number and % of all blood cell types.
• Size and its variation in RBC
• Hemoglobin mass and concentration
• One of the best initial test used in diagnosis of myriad hematological
pathologies.

4. Normal CBC

8. Peripheral Smear
It is performed for:
1. Differential leucocyte count (DLC)
2. General assessment and verification of various cell counts.
3. Study of RBC morphology for classifying various anemias.
4. Study of WBC morphology for diagnosing leukemias and other WBC
disorders.
5. Study of platelet morphology for diagnosing some platelet disorders.
6. Study of parasites found in plasma or WBC or RBC (haemoparasites).
7. Study of other defects like rouleaux formation, agglutination,
fragmentation, red blood cell inclusions, WBC inclusions, platelet clumps
and satellitism etc.

10. Peripheral Smear in Anemias
• ABNORMALITIES OF SIZE
• ABNORMALITIES OF COLOUR
• ABNORMALITIES OF SHAPE
• INCLUSIONS IN RBC

11. ABNORMALITIES OF SIZE
• Anisocytosis:
If the size of RBC varies, in the same blood film, beyond normal limits, it is termed
anisocytosis.
• Microcytosis:
When the average size of RBC in a blood film is less than normal it is termed microcytosis.
The degree of microcytosis is directly proportional to decrease in MCV.
• Macrocytosis:
When the average size of RBC is more than normal, it is termed macrocytosis. The degree
of macrocytosis is directly proportional to increase in MCV.

12. ABNORMALITIES OF COLOUR
• Hypochromic cells
• Target cells:
have a central haemoglobinised area, surrounded by a pale ring and then a peripheral
haemoglobinised area.
*Hypochromic RBC is the result of iron deficiency and reduced heme content in cells

14. ABNORMALITIES OF SHAPE
• Poikilocytosis:
• When the shapes of RBCs vary more than expected in normal individuals, in the blood film, it
is termed poikilocytosis. RBC of abnormal shape is termed a poikilocyte.
• Spherocytes:
• When RBCs are more spheroidal than normal, these are termed spherocyte.
• Elliptocytes and Ovalocytes:
• About 10% RBC in a normal blood film, particularly at the tail end, appear oval and less
commonly elliptical in shape.
• Schistocytes:
• These are fragmented red blood cells of various shapes and sizes. Large cells from which
portions are fragmented some times appear as helmets and are called helmet cells.
*Continued…….

16. *Continued…
• Echinocytes and Burr cells:
Echinocytes or crenated cells have evenly distributed blunt spicules of uniform size on their
surface.
• Acanthocytes:
These are small densely staining RBC with thorn like projections. Generally the projections
are fewer, of varying sizes, variable number and more blunted than echinocytes.
• Sickle cells:
These are thin, elongated, deeply staining red cells with elongated ends. These may be
straight, curved or of various other shapes.

17. INCLUSIONS IN RBC
• Howell-Jolly bodies:
These are small rounded fragments of the nucleus staining reddish-blue to blue-black
resulting from incomplete extrusion of the nucleus.
• Basophilic stippling or punctate basophilia:
These are fine to coarse, deep blue to purple, small but multiple inclusions of varying sizes.
These represent aggregated ribosomes.
• Cabot rings:
This is thin reddish blue, ring like structure occupying varying portion of RBC. It may be
twisted to form figure of 8.

18. DLC
• Differential leucocyte count (DLC) provides the relative number of
each type of leucocyte in blood. It is performed on a well-spread and
well-stained blood film.

19. • DLC is commonly reported as percentage or absolute number
calculated from TLC of each type of cell as under;
1. Neutrophils
2. Lymphocytes
3. Monocytes
4. Eosinophils
5. Basophils
6. Various maturation stages e.g., blasts, promyelocytes, metamyelocytes and
band forms.

22. Reference range
Cells Count x109/L %
Neutrophils 2.0-7.5 40-75%
Lymphocytes 1.5-4.0 20-45%
Monocytes 0.2-0.8 02-10%
Eosinophils 0.04-0.3 01-06%
Basophils <0.01-0.1 <1%

23. Neutrophil

24. Neutrophil showing
drumstick

25. Neutrophils showing
hypersegmented nuclei

26. Eosinophil

27. Basophil

28. Lymphocyte

30. Monocyte

31. Coagulation Tests
• PT
• aPTT
• BT/CT
• FDP

33. PT/aPTT

34. BT/CT

35. Interpretation
PT aPTT CT BT
Prothrombin time is
prolonged
conditions such as
liver disease,
vitamin k deficiency
or a coagulation
factor deficiency
(e.g., factor VII
deficiency).
Deficiency of factors
XII, XI, IX, VIII, X, V
or
II
•von Willebrand
disease
• Circulating
anticoagulants
• Massive
transfusion of
stored blood
• Liver disease
• DIC
Clotting time is
prolonged in:
• Severe Hemophilia.
• Severe Christmas
disease
• Anticoagulant
therapy particularly
with
heparin
• Factor XII deficiency.
• Circulating
anticoagulants
Prolongation of BT
commonly occurs in:
•
Thrombocytopenia
• von Willebrand
disease
• Platelet function
defects
• Aspirin ingestion
• Severe deficiency
of Factor V or XI
• Afibrinogenemia

36. THE END