13 - Anaemia 1 Flashcards
How many RBC are there
24 x10^12 trillion RBC - 1/3 total body cells
How much iron should the diet contain
15mg iron/day
What is the total body iron
3-5g
1mg absorbed and 1 mg excreted in urine/faeces, hair so balance, 2g iron is in the form of circulating Haemoglobin
Where is the majority of the iron absorbed in
duodenum by enterocytes
Iron only taken up as Fe++
What enzyme reduces Fe3+ to Fe2+
Ferric reductase
What is transferrin
Iron binding blood plasma glycoproteins
Takes iron from inside the enterocyte into the blood to the bone marrow
What does transferrin carry iron as
The ferric form FE3+
it can carry 2 irons
What takes up iron
Ferritin
What does levels of transferrin tell you
The ability of the blood to transfer iron from enterocytes
Ferritin
The iron is stored here
= it can release iron in a controlled manner
Where is ferritin found
In most tissues
and small amounts in the plasma as a carrier
What does plasma ferritin indicate
Indirect marker of the total amount of iron in the body
What does serum ferritin indicate
used as a diagnostic test for iron deficiency anaemia
What do you do if the Hb is low
History and examination Full blood count and blood film Serum B12, folate and ferritin Test renal and liver function ESR - check if infection
What are further tests you can do
Hb electrophoresis
Bone marrow biopsy
What is anaemia
Low Hb level
Not a diagnosis
What are the levels of hb for an adult male and female
<13.5 g/dl - male
<11.5 g/dl (female)
What are the levels of hb for a human of age 6months - 6 y/o
<11 g/dl
What are the levels of hb for a human of age 6 y/o to 14 y/o
<12 g/dl
What are symptoms of anaemia
Tiredness
Fainting
SOB
palpitations
What are signs of anaemia
Pallor
Rapid heartbeat
Bounding pulse
Systolic flow murmur
What are causes of anaemia
Decrease in RBC production due to iron, folate, b12 deficiencies, infections, chronic disease
Increased destruction of RBC - haemolytic anaemia
Increase loss of RBC - bleeding
What is microcytic anaemia
<76fl
Iron deficiency
Thalassaemia
What is normocytic anaemia
76 - 96fl
Recent bleed
Chronic disease
Haemolytic anaemia
What is macrocytic anaemia
> 96fl
B12 or folate def
Alcohol/liver disease
What are 2 signs of iron deficiency anaemia on a blood film
Microcytic
hypochromatic (reduced hb)
Why can you get iron deficiency anaemia
Low iron in diet
Reduced RBC synthesis
Excess iron loss
What factors increase iron absorption
Haem irons ferrous salts (Fe2+) Acid ph Pregnancy Hypoxia
What factors impair iron absorption
Non-haem iron (veg) Ferric salts (Fe3+) Alkaline PH Iron overload Inflammatory disorders Proton pump inhibitor
What are some risk factors for anaemia
Sex (Females>Males) Appetite changes Drugs - Aspirin, NSAID Diet - Vegans, elderly Physiological - Pregnancy, adolescence
How would you confirm iron deficiency anaemia
1) Blood count = Low RBC number
2) Blood film = Microcytic, hypochromatic
3) Serum ferritin - Low
4) Serum iron total binding capacity - Low
What is the treatment for iron deficiency anaemia
Replace the iron
Improve the diet
Use iron tablets (ferrous sulphate)
How long do you continue iron supplements once the Hb is normal
3 months
What are causes of normocytic anaemia
Acute blood loss
Chronic disease
Cancer
Haemolysis
Why does chronic disease cause normocytic anaemia
Inflammation - reduces RBC lifespan - depressed erythropoiesis - poor marrow response to EPO (inflammatory cytokines interfere with EPO production/action)
