Red Cells Flashcards
normal red cell lifespan
12 days
what are some substances necessary for red cell production?
iron
B12, folic acid
AAs
erythropoietin
nature red blood cell
erythrocyte
haemoglobin
the iron-containing oxygen-transport metalloprotein in the red blood cell
what is bilirubin?
a product of haem degradation (which occurs in the spleen)
it gets transferred to the liver where it gets conjugated to make it more water soluble
then helps with digestion
conjugated bilirubin is excreted where? what for?
into bile to help in food digestion
you get some excess in stool and urine
congenital reduced red cell survival results in
haemolysis
haemolysis
destruction or rupture of red blood cells
G6DP deficiency
cells vulnerable to oxidative damage
commonest disease causing enzymopathy in the world
signs: anaemia, neonatal jaundice, splenomegaly, pigment gallstones
triggers to haemolysis in G6DP
broad beans
acute illness
infection
drugs
Bohr effect gives what?
hypothermia
acidosis
haemoglobin gas exchange:
O2 to tissues
CO2 to lungs
difference between haemoglobin in sickle cell and normal:
Normal:
2 alpha chains
2 beta chains
Sickle Cell:
2 alpha chains
2 beta (sickle) chains
anaemia
either low RBC number
or low haemoglobin
(Hb below normal for age and sex)
what are the 3 main types/ morphological descriptions of anaemia?
hypochromic microcytic
normochromic normocytic
macrocytic
how do you test to see if its hypochromic microcyctic anaemia?
serum ferritin
how do you test to see if its normochromic normocytic anaemia?
reticulocyte count
how do you test to see if its macrocytic anaemia?
B12/ folate
bone marrow
absorbed iron in the body is stored as
ferritin
thalassaemia
mostly genetic
people make no or too little haemoglobin (absence or disfunction of alpha or beta chains in haemoglobin)
what is the commonest cause of anaemia?
iron deficiency
clinical features of iron deficiency
hypochromic microcytic red cells
kolinychia
atrophic tongue
angular cellulitis
causes of iron deficiency
GI blood loss
menorrhagia
malabsorption (gastroectomy, coeliac disease)
diet
increased requirement (like in pregnancy)
how do you manage iron deficiency?
correct the deficiency: oral/IV iron, blood transfusion
correct the cause: diet, ulcer therapy, gynae interventions, surgery
if the reticulocyte count is INCREASED what does this show?
test for normochronic normocytic anaemia
acute blood loss
haemolysis
if the reticulocyte count is DECREASED/ NORMAL what does this show?
(test for normochromic normocytic anaemia)
secondary anaemia
hypoplasia
marrow infiltration
what is secondary anaemia?
anaemia of chronic disease
underlying causes of secondary anaemia
infection
inflammation
malignancy
haemolytic anaemia
accelerated RBC destruction - so a lower Hb
compensation by bone marrow - increased reticulocytes
haemolysis can be acquired or congenital. Acquired is mostly
immune (extravascular)
non-immune (intravascular)
direct antiglobulin test detects what?
coombs test
immune haemolytic anaemia
haemolytic anaemia. tests to find out why is the patient haemolysing?
FBC, reticulocyte count, blood film
serum bilirubin
haemolytic anaemia. tests to find out the mechanism:
history and exam
blood film
direct antiglobulin test (coombs test)
two types of macrocytic anaemia
non-megaloblastic
megaloblastic
what is the commonest cause of a B12 deficiency in the western world?
pernicious anaemia
what type of disease is pernicious anaemia?
auto immune
mechanism behind pernicious anaemia:
autoantibodies against:
- intrinsic factor
- or gastric parietal cells
malabsorption of dietary B12
(as dietary B12 binds to intrinsic factor secreted by parietal cells)
how do you treat pernicious anaemia?
replace vitamin
B12 IM injection
Folate oral replacement
folic acid deficiency in pregnancy can cause what?
neural tube defects (eg spina bifida)
cleft palate
what are the general anaemia symptoms?
tired/pallor
breathlessness
swelling of the ankles
dizziness
chest pain
