Anaemia Treatments IN EXAM Flashcards
what makes an anaemia microcytic and hypochromic
low MCV and low MCH (low Hb, what gives it low colour)
what causes microcytic anaemias
problems with Hb synthesis = iron deficiency or haemoglobinopathies (alpha/ beta thalassaemia)
why do you get anaemia in iron deficiency
cant form heam (porphyrin ring and Fe2+)
why are cells microcytic in iron deficiency anaemia
In the bone marrow the erythroblasts start as large nucleated cells, the nucleus is responsible for production for haemoglobin. The signal for enucleation is when cell reaches critical point of Hb. With each cell division the cell gets smaller, if the cell isn’t making much Hb it will continue divide and so there are more divisions than normal and therefore the cells are microcytic.
what does ferittin measure
stored iron
where is iron stored
macrophages, liver, spleen, bone marrow
can iron be raised in iron deficiency
yes- if acute inflammatory process there will be high ferittin as it is an acute phase protein
name 3 iron supplements
ferrous sulphate
ferrous fumarate
ferrous gluconate
what is the therapy of choice for iron deficiency anaemia
ferrous sulphate 200mg TDS
what are side effects of ferrous sulphate
(not uncommon for people to not tolerate them)
- constipation
- diarrhoea
- epigastric pain
- faecal impaction
- GI irritation
- nausea
what are the alternative options if someone is struggling to tolerate iron supplements
take the pill with food reduce dose to BP or QD encourage dietary iron intake avoid tea (tannis impair absorption of iron) vitamin C enhances iron absorption
ferrous gluconate 300mg
if cant tolerate at all can give S/c or IM iron
what are sources of iron in diet
red meat
green veg
breakfast cereals fortified
what should you worry about in older people/ non menstruating female with iron deficiency anaemia
right sided colon (caecal) cancers- can cause occult blood loss
what Ix for non menstruating females/ males with iron deficiency anaemia
colonoscopy, up GI endoscopy
why do children develop anaemia more easily than adults
as have increased need for iron and so can develop deficiency more easily
what is the commonest reason for not improving on iron replacement therapy
non compliance
how much should Hb conc rise on iron therapy
2g/100ml over 3-4 weeks
what tests can assess response to iron therapy
reticulocyte count (marker of bone marrow activity) ferritin levels
when is blood transfusion indicated for iron deficiency anaemia
Hb <70g/l
why are people usually well in chornic anaemia
Haemoglobin will change to become more efficient at delivery to the tissues. The oxygen dissociation curve will shift to the right to increase oxygen tissue delivery to the tissues (increase in 2,3-BPG)
what Tx if iron deficiency unresponsive to Tx
Im iron injection
dietary advice
find cause
what are B12 and folate required for
cell mitosis
is there b12 in seafood
yes
where is B12 absorbed
terminal ileum
what does B12 bind to
intrinsic factor which is secreted by gastric parietal cells which binds to B12 and facilitates transport across terminal ileum
what are common causes of B12 deficiency
crohns (terminal ileum)
diet
metformin (affects absorption)
pernicious anaemia
what antibodies will be present in pernicious anaemia
anti IF (intrinsic factor) (these are specific)
gastric pariental cell antibodies not specific but are sensitive so these used less
Antibodies can either bind to gastric parietal cells and prevent secretion of IF or they can bind to IF and prevent it binding to B12
what is pernicious anaemia associated with
hypothyroidism, vitiligo, addisons disease
what is the treatment for pernicious anaemia
IM vit B12 injections lifelong (1mg 3x a week for 2 weeks, then 1mg every 2-3 months)
alternatives= massive oral doses of B12
what is the pathology of pernicious anaemia
- Autoantibodies to the gastric parietal cells of the stomach result in reduced intrinsic factor release and therefore no absorption of vitamin B12 can occur in the terminal ileum of the small bowel
- This results in macrocytic anaemia due to inadequate nuclear maturation of the red cell precursors in the bone marrow and a subsequent apoptosis of dysfunctional red cell precursors
- With the injections of vit B12; normal red cell production can occur resolving the anaemia
what is the treatment for macrocytic anaemia in an alcoholic with folate deficiency
5mg folic acid for 3-4 months (or lifelong if think high risk)
would also give B12 injections as important for myelin shealth development
(if you were to just give folate on its own you would switch on haematopoesis and use up B12 quickly causing irreversible neuro disorders)
blood count in 4 weeks to check levels
what can a combined deficiency of folate and B12 cause
irreversible sub acute combined degeneration of the cord
how can alcohol affect rbcs
cause macrocytosis
how can liver disease cause anaemia
causes MACROcytic anaemia due to abnormal lipid metabolism = dysfunctional red cell membrane
(important to remember in alcoholics) (also consider NAFLD)
what will you see on blood film of someone with macrocytic anaemia
target cells
why is folate low in alcoholics
poor diet
damage to liver
why can you get high B12 in alcoholics
as is released when liver is damaged
