CBC and the Blood Film Flashcards
which is the recommended anticoagulant used in blood collection?
K2EDTA
from where can blood be taken?
- venous
- arterial
- capillary
- cord blood
what are the white cell parameters investigated in a CBC?
- total white count
- neutrophils
- basophils
- eosinophils
- lymphocytes
- monocytes
- [immature granulocytes]
- [blasts]
what are the red cell parameters investigated in a CBC?
- haemoglobin
- haematocrit
- red cell count
- mean cell volume
- mean cell haemoglobin
- mean cell haemoglobin concentration
- red cell distribution width
- [reticulocytes]
- [nucleated red blood cells]
what are the platelet parameters investigated in a CBC?
- platelet count
- mean platelet volume
which are the primary measurements in a CBC?
- Hb
- haemocrit
- red blood cell count
which are the derived measurements in a CBC?
- MCV
- MCH
- MCHC
what does a flow cytometry?
diagnoses haematological malignancy
how is the haemoglobin count obtained in a CBC?
red cells are lysd by specific reagents which also bind haemoglobin
how is the haemoglobin concentration obtained?
measuring the light absorption or a specific wavelength
how is the RCC obtained?
a stream of cells are directed into a sensing zone where, when sensed, they generate an electrical impulse, which can be quantified
how is the MCV obtained?
calculated from the height of the impulse obtained in the RCC
haematocrit is the product of which two values?
- RCC
- MCV
how do you get the reticulocyte count?
flourescence penetrates the cells and detects the RNA, which ultimately, contributes to the overall intensity of the flourescence signal, which is proportionate to the nucleic acid content
how is the WCC and differential given?
the same away as the reticulocyte count
which are the abnormalities that can be found in a CBC?
- leukocytosis
- leukopenia
- anaemia
- polycythaemia
- reticulocytosis
- thrombocytosis
- thrombocytopenia
what are the steps of a blood film preparation?
- spreading
- drying and fixation
- staining
which types of dye can be used?
- acidic dye
- basic dye
- MGG (mixture of an acidic and basic dye)
what should you check for in a macroscopic blood film examination?
- background staining
- cold agglutination
what should the red blood cells look like in a blood film?
- biconcave
- central area of pallor
which type of white blood cells are not usually found in a blood film?
- eosinophil
- basophil
how can a red blood cell be abnormal?
- size
- shape
- colour (haemoglobinisation)
- abnormal add-ons
how can the size of the red cell be abnormal?
- microocytosis
- macrocytosis
- anisocytosis
how can the shape of the red cell be abnormal?
- poikilocytosis
how can the colour of the red cell be normal?
- hypochromasia
- polychromasia
- anisochromasia
what abnormal inclusions can be found in the blood film?
- howell-jolly bodies
- basophilic stippling and pappenheimer bodies
- parasites
causes of microcytosis, hypochromasia
- iron deficiency
- thalassemia
- late anaemia of chronic disease
causes of macrocytosis
- B12 and folate deficiencies
- hypothyroidism
- liver failure
- myelodysplasia
- drugs
when do target cells appear?
- thalassemia
- haemoglobinopathies
- iron deficiency
- liver disease
causes of spherocytosis
- hereditary spherocytosis
- immune haemolysis
causes of tear drop poikilocytes
- myelofibrosis
- bone marrow infiltration
causes of fragments in the blood film
- microangiopathic haemolysis
- TTP, HUS, DIC etc
what shape of red cell is characterised in B12/folate-deficiency anaemia?
oval
causes of a high MCV
- haemolytic anaemia
- cells getting stuck together
