T2 L4, Introduction to Anaemia Flashcards
What is anaemia?
When the Hb concentration falls below a defined level leading to insufficient O2 delivery
Why is the normal Hb concentration higher in men then women?
Because men have more testosterone which adds an arithropoetic drive
Why is the normal Hb range lower in pregnant woman than not pregnant?
Because more plasma is produced so the red blood cells are diluted but pregnant women do produce more RBC’s
What are some symptoms of Anaemia?
Lethargy, fatigue, shortness of breath, palpitations, headache
What are some signs of Anaemia?
Skin pallor, pale conjunctivae, tachypnoea, tachycardia, koilonychia (spoon nails)
What are the main causes of Anaemia?
Problems of inadequate blood synthesis (insufficient Fe, B12 and Folic acid or a mone marrow dysfunction) or a problem with blood loss or consumption (bleeding or haemolysis)
Why can chronic bleeding cause anaemia?
The bone marrow can compensate for blood loss until iron is used up
Describe the Serum Ferritin diagnostic test
It show how much iron is stored within the body iron store
What is Ferritin?
The storage form of iron within the body
Describe the Serum Iron diagnostic test
It reflects recent intake of iron
Describe the Serum Transferrin diagnostic test
It reflects the total iron binding capacity (TIBC) of the blood
What is Serum Transferrin?
A iron carrier molecule from gut to stores. It homeostatically goes up if iron is deficient
Describe the % Transferrin Saturation as a diagnostic test
A sensitive measure of iron saturation that reflects the proportion of transferrin that’s iron bound. A low TF saturation indicates iron deficiency
What is the Iron time to deficiency?
6-8 years in adult male
What is the vitamin B12 time to deficiency?
3-4 years
What is the Folic acid time to deficiency?
4 months
What is mean corpuscular volume?
The mean cell volume (size of red blood cells)
What is the normal mean corpuscular volume?
80-100 fL
What is the meaning of Microcytic and what does this indicate?
Small red blood cells. Indicates iron deficiency. Can be caused by inherited disorders like Thalassaemia
What is the meaning of Macrocytic and what does this indicate?
Large red blood cells. Indicates B12 and Folate deficiency. These are over mature cells
What is the meaning of normocytic and what does this indicate?
Normal red blood cells. Can indicate acute haemorrhage and renal failure
What are reticulocytes?
newly formed RBC’s (about 1 day old)
What does a reticulocyte count indicate?
Indicates the rate of RBC production in the bone marrow
When is a reticulocyte count low?
During precursor deficiencies and if the bone marrow is infiltrated
When is a reticulocyte count high?
During chronic bleeding and haemolysis
What drives red blood cell production?
Erythropoetin from kidney
What are the 4 blood film morphologies in iron deficiency?
Hypochromia, Microcytosis, pencil cells and target cells
What is Megaloblastic anaemia?
Macrocytic cells (MCV) caused by vitamin B12 and Folate deficiency
What is MCV?
Mean corpuscular volume
What is B12 and Folate required for?
DNA synthesis
What is Pernicious Anaemia?
Caused by B12 deficiency because there is an autoimmune destruction of intrinsic factor secreting parietal cells
What is the most common form of anaemia in hospitalised patients?
Anaemia of chronic disease caused by chronic inflammation or infection
What is sickle cell anaemia?
A mutation in the beta globin gene causing HbS (sickle Hb). This causes increased cell turnover and therefore raised reticulocytes
What are the characteristics of Thalassaemia?
It’s an inherited autosomal recessive gene that causes insufficient production of normal Hb
What are the 3 types of bone marrow infiltration?
Leukaemia, Lymphoma and Myeloma
Where is a bone marrow sample obtained from?
The iliac crest (Hip bone)
What 2 things can long-term transfusion cause?
Iron overload and Allo-antibodies to foreign RBC’S
