Anaemia Flashcards
anaemia definition
red total RBC mass
what are the 2 possible pathophysiologies of anaemia
increased destruction of RBCs eg bleeding, haemolysis
decreased production of RBCs
what is the problem in microcytic anaemias
there is a problem with the haemoglobin production
either heme problem or globin problem
microcytic anaemia, potential causes of haem deficiency caused by iron deficiency (4)
low dietary intake
anaemia of chronic disease
malabsorption
blood loss
microcytic anaemia, cause of globin deficiency
thalassaemia
most common cause of microcytic anaemia
who gets it
low iron dietary intake
veggie/vegans
microcytic anaemia, potential causes of haem deficiency not caused by iron deficiency (2)
porphyrin synthesis problem - lead poisoning
genetic
pneumonic for remembering causes of microcytic anaemia
find the small cell
Fe deficiency - diet, malabsorption, blood loss, anaemia of chronic disease
Thalassaemia
Sideroblastic anaemia (don’t need to know)
anaemia of Chronic disease
relative iron deficiency anaemia
eat ‘enough’ iron but not enough for body eg pregnant, children
absolute iron deficiency anaemia
don’t eat enough iron
what is anaemia of chronic disease
when you have enough iron intake but cant use it
second most common cause of anaemia after iron deficiency
anaemia of chronic disease
causes of anaemia of chronic disease
malignancy
infection
inflammatory (eg rheumatoid arthritis)
in anaemia of chronic disease, the cause of the problem is due to increased inflammatory cytokines, what does this then lead to the production of
what does this do
hepcidin
inhibits release of iron from duodenum = decreased Hb production in bone marrow = anaemia
NOTE inflammatory cytokines also decrease EPO from kidneys and directly inhibit erythropoiesis in bone marrow, but above is the main mechanism
example of chronic condition with malabsorption of iron
coeliac
causes of blood loss that can cause anaemia (3)
GI bleed
haematuria
menorrhagia
cause of porphyrin synthesis problem = haem deficiency = anaemia
lead poisoning
globin deficiency
thalassaemia
why does haemoglobin deficiency cause MICROCYTIC anaemia
bone marrow still makes RBCs, they just contain less Hb than normal = smaller with less Hb (low MCV)
is haemogllobin deficiency hypo or hyperchromic anaemia
hypochromic - less Hb than normal RBCs
when do people present with symptoms in microcytic anaemia
late stage
once microcytic anaemia has been diagnosed, what do you want to measure to diagnose cause
serum ferritin
if low = iron deficiency cause
if high = globin problem (thalassaemia)
iron deficiency anaemia diagnosed (microcytic anaemia with low serum ferritin), what do you do
prescribe fe2+ supplements (ferrous fumarate)
AND investigate cause further for blood loss - FOB, endoscopy etc
what blood component will be increased in microcytic anaemia
why
platelets = thromobocytosis
bone marrow compensates for decreased RBCs = tries to make more, platelets come from same precursor