intro to anaemia Flashcards
define anaemia
a haemoglobin conc lower than normal range
is anaemia itself a diagnosis
no but a manifestation of an underlying disease
what are the main symptoms of anaemia
- shortness of breath
- palpitations
- headaches
- claudication (muscle pain due lack of O2)
- angina
- weakness and lethargy
- confusion
what are the main signs of anaemia
- pallor
- tachycardia
- systolic flow murmur
- tachypnoea
- hypotension
what are specific clinical signs associated with the cause of anaemia
IRON DEF:
- koilonychia (spoon nails)
- angular stomatitis (inflam corners mouth)
VIT B12 DEF:
-glossitis (imflam tongue)
THALASSAEMIA:
- abnormal facial development
what are the three causes of anaemia in bone marrow
- reduced or dysfunctional erythopoiesis
- abnormal haem synthesis
- abnormal globin chain synthesis
what are the four causes of anaemia in peripheral blood cells
abnormal structure
mechanical damage
abnormal metabolism
excessive bleeding
what are the causes for anaemia in removal or RBC
increased removal by reticuloendothelial system
how can anaemia develop from reduced erythropoiesis
- lack of response in haemostatic loop so in chronic kidney disease kidney stops making erythropoietin
- marrow does not respond to EPO
- marrow infiltrated by cancer or fibrous tissue so less haemopoietic cells
- iron not made available for RBC
- myelodysplastic syndrome abnormal stem cells in marrow
how can anaemia develop from defects in Hb synthesis
- mutations in genes for globin –> thalassemia
- defects in haem synthesis –> sideroblastic anaemia
- insufficient iron in diet to make haem
how can anaemia develop from abnormal structure (inherited)
- mutations in genes coding for proteins involved in interactions between plasma mem and cytoskeleton
- less flexible and more easily damaged
- break up in circulation and removed more quickly by RES
how can anaemia develop from mechanical damaged (acquired)
- damaged caused by mechanical valves
-cells snagging on fibrin strands in small vessels causing clots - heart damage from severe burns
osmotic damage (drowning)
what are the fragments called when RBC go under mechanical damage
schistocytes
why might anaemia develop from defects in cell metabolism
- G6PDH deficiency:
more ox stress to RBC –> Heinz bodies and cleared by RES - pyruvate kinase deficiency:
RBC no mito so deficient in ATP without pyruvate kinase so undergo haemolysis
why might anaemia develop from excessive bleeding
- acute blood loss (injury, surgery, childbirth, ruptured vessel)
- chronic bleeding (menstruation, nosebleeds, haemorrhoids, gastro bleeding in stool, kidney or bladder tumours)
- chronic NSAID usage (aspirin, ibuprofen, naproxen,)
(induce GI bleeding by inhibiting cyclooxygenase activity = toxic)
why might anaemia develop from reticuloendothelial system
- in haemolytic anaemias RBCs destroyed more quickly as abnormal or damaged
- damage can occur in blood vessels (intravascular) or in RES (extravascular)
- autoimmune anaemia causes antibodies to bind to RBC mem so recognised by spleen
what two factors can help determine cause of anaemia
RBC size
presence or absence or reticulocytes
what are reticulocytes
immature RBC
- no nucleus and eliminate remaining mitochondria
- take one day to mature
what are the causes of macrocytic anaemia
- Vit B12 def
- folate def
- myelodysplasia
- liver diease
- alcohol toxicity
what are the three types of macrocytic anaemias
- megaloblastic
- macronormoblastic
- stress
what is macrocytic anaemia
where average size of RBC is greater than normal so higher MCV
what is megaloblastic anaemia
- interfers with DNA synth during erythropoiesis during development of nucleus so nuceluar, cytoplasmic dssynchrony as cell division delayed but cell continues to grow = larger cells = megaloblasts
what are examples of causes of macrocytic anaemia
- Vit B12/ folate def
- drugs that interfer with DNA synth
- erythroid leukaemias
what is macronormoblastic anaemias
larger erythroblasts are larger than normal and give rise to larger than red cells
