6 Blood Counts and Films Flashcards
What are some factors which would cause errors in pathology results?
- Specimen collection mix up
- Specimen delivery delayed/not delivered
- Specimen analysis- technical error
- Responsive action- results not reviewed
What should you do if you get an abnormal/unexpected result?
REPEAT
What ‘turn around times’ for FBCs should be expected?
Urgent A&E= 1hr
Non-urgent (ward)= 4hrs
GP= 24hrs
What parameters can a Full Blood Count look at?
- Red cells
- Indices (size and haemoglobin content)
- Count
- Haemoglobin
- Platelets
- Count
- Size
- White cells
- Count
- Full
How is spectrophotometry used to measure haemoglobin content in RBCs?
Measures amount of light absorbed by sample=proportional to amount of compound in it
What is Flow cytometry and how does it work?
- Hydrodynamic focussing- single file line of cells
- –> passes through light beam
- Impedance counting
- More scatter=bigger cell
What is Packed cell volume?
Proportion of blood made up of RBCs
(Centrifuged to allow visualisation)
What is polycythemia?
Haematocrit (Volume % of RBCs) is elevated
What could occur to cause an incorrect measurement of haemoglobin levels? (2)
- Turbidity of plasma
- Invitro haemolysis/clotted sample (reduce Hb)
What are the normal haemoglobin levels?
What are the units for Red Cell Count?
x 1012/L
If the RCC is reduced, what could this be an indicator for?
Microcytic anaemia due to iron deficiency
(MCV also likely to be reduced)
What may cause an elevated RCC?
Microcytic anaemia- thalassemia trait
(MCV also likely to be reduced)
If a patient has a high mean cell volume, this may indicate anaemia.
What may have caused this anaemia?
- B12/Folate deficiency (Megaloblastic anaemia)
- Liver disease
- Alcohol, smoking
- Hypothyroidism
- Drugs
- Myeloma
If a patient has a low mean cell volume, this may indicate anaemia.
What may have caused this anaemia?
Iron deficiency anaemia
Thalassaemia
Anaemia of chronic disease
Lead poisoning
What is anisocytosis?
Patients RBCs= of unequal size
(Increased Red Cell Distribution Width)
What may cause anisocytosis?
- Iron deficiency
- Thalassaemia trait
- Post-transfusion
What is Mean Cell Haemoglobin?
Average measure- Hb in each RBC
What may cause an increase in mean cell haemoglobin?
Spherocytosis
What may cause reduced Mean Cell Haemoglobin?
Iron deficiency
What factors do we use to identify reticulocytes?
- Size
- RNA content
If reticulocyte count was elevated, what may have caused this?
- Increased EPO
- Recent blood loss
- Response to iron/vit B12/ folate replacement
- Haemolytic anaemia
- Recovery from bone marrow suppression
What may cause a reduced reticulocyte number?
- Haematinic deficiency
- Bone marrow failure
Why might a sample be flagged as requiring a blood film?
- Results from FBC=significantly outside normal range/significant change from last results
- Analyser thinks there are abnormal cells
How is a blood film carried out?
Small drop of blood- spread on glass- one layer thick
Fixed w./ methanol–> stained–> enable microscope visulisation
What do each of the following terms mean?:
Microcytic
Macrocytic
Hypochromic
Hyperchromic
What do each of the following mean?
Describe each of the following:
Fill in the missing labels:
Fill in the missing labels:
Fill in the missing labels:
Fill in the missing labels:
What results would you expect to see for an Iron Deficiency?
What results would you expect to see if someone had spherocytosis?
What results would you expect to see from an iron deficiency?
