red cells + acquired anaemias Flashcards
factors influencing ‘normal range’ of haemoglobin levels
age sex ethnic origin time of day sample taken time to analysis
male haemoglobin reference ranges
12-70: 140-180
>70: 116-156
female haemoglobin reference ranges
12-70: 120-160
> 70: 108-143
general features of anaemia
tiredness pallor breathlessness swelling of ankles (heart failure) dizziness (adjustment of BP) chest pain - myocardial ischaemia
anaemia causes: problem with production in bone marrow
cellularity
stroma
nutrients - not enough iron, folate etc
anaemia causes: problem with red cell
membrane
haemoglobin
enzymes
anaemia causes: problems with destruction and loss
blood loss
haemolysis
hypersplenism - pooling of blood in spleen
red cell indices
automated measurement of red cell size and haemoglobin content
MCH
mean cell haemoglobin
MCV
mean cell volume (cell size)
hypochromic microcytic anaemia
small pale cells
normochromic normocytic anaemia
huge number of anaemias
normal amount of Hb and avg normal cell size
macrocytic anaemia
big red cells
bigger cells but usually with less Hb - usually pale
hypochromic microcytic anaemia first investigation to do
serum ferritin - measure of body iron store
if low = iron deficiency
if normal/inc = thalassaemia, 2ry anaemia (sideroblastic anaemia)
normochromic normocytic anaemic first investigation to do
reticulocyte count
if bleeding or haemolysis this count will increase
low if bone marrow nor working
first investigation to do if macrocytic anaemia
B12/folate + bone marrow
commonest cause = B12 or folate deficiency
if B12 + folate normal then bone marrow problem e.g. malignancy
hypochromic microcytic anaemia: secondary anaemia
normal ferritin with abnormal iron utilisation if background inflammation
intake and loss of dietary iron
absorbed by duodenum
lost by intestinal cells (+ menstruation in women)
dietary iron absorption
- iron from diet can be haem or non-haem
- enter through villi of duodenum, ferroportin transports it across into circulatin
- bind to transferrin which carries it to liver (if needed for making blood) or to liver where it is stored as ferritin
hepcidin
synthesised by hepatocytes in response to increased iron levels, binds to ferroportin and inactivates it
stops you absorbing more iron than you need
iron and inflammation
iron can be redirected into inflammatory processes
hepcidin switches on to allow this to happen
signs of iron deficiency
kooilonychia
angular chelitis
atrophic tongue
causes of iron deficiency
GI blood loss
menorrhagia
malabsorption - gasterectomy, coeliac
management of iron deficiency
correct deficiency - oral iron usually sufficient (IV if intolerant), blood transfusion rarely indicated
correct cause - diet, ulcer therapy, gynae intervention, surgery e.g. tumour
