Anaemia and Microcytic Anaemia Flashcards
define anaemia
reduced total red cell mass
name surrogate markers of anaemia?
haemoglobin conc
haematocrit
normal Hb for men?
130-180g/L
normal Hb for women?
120-180g/L
why do men have higher Hb levels?
more testosterone
haematocrit levels are higher in men or women?
men
red cell production occurs where?
bone marrow
how do you create a Hb solution?
lyse red cells
what is haematocrit?
the ratio of the volume of red cells to the total blood volume
when would Hb and haematocrit levels not be a good marker of red cell mass and why?
rapid bleeding
if fluids have been given
both cause plasma expansion
how does the body respond to anaemia?
increased red cell production
red cells that have JUST left the bone marrow are called…
reticulocytes
are reticulocytes or RBCs larger?
reticulocytes
what colour do reticulocytes stain and why?
purple/blue as they have RNA
“polychromatic blood film”
reticulocytes
how is haematocrit calculated?
red cell number x red cell volume
what is MCV?
size of the red cells (mean cell volume)
what blood test looks at cellular morphology (shape)?
blood film
when would you do a reticulocyte count?
to assess bone marrow response
2 main causes of anaemia?
decreased production
increased loss
what is a marker of decreased red cell production?
low reticulocyte count
what is a marker of increased red cell loss?
high reticulocyte count
causes of low reticulocyte count?
hypoproliferative - reduced erythropoesis
maturation abnormality - ineffective erythropoesis
what can make erythropoesis ineffective?
impaired haemoglobinisation
impaired cell division
causes of high reticulocyte count?
bleeding
haemolysis
if MCV is low and patient is anaemic what could be the cause?
haemoglobinisation problems in the cytoplasm
if MCV is high and patient is anaemic what could be the cause?
cell division
got big cells that cant divide
iron and porphyrin meet where in the cell to make haem?
mitochondrion
appearance of microcytic anaemia cells?
hypochromic - lack of colour from lack of Hb
small
haemoglobin synthesis occurs where?
cytoplasm
commonest and 2nd most common cause of microcytic anaemia?
iron deficiency
thalassaemia
define thalassaemia
cant make globin chain
how does anaemia of chronic disease differ from iron deficiency anaemia in terms of iron levels?
normal body iron but lack of available iron
its common for porphyrias to cause microcytic anaemia T or F
F
what kind of poisoning can cause problems with porphyrin synthesis?
lead
microcytic anaemia is caused by…
haemoglobinisation problems
macrocytic anaemia is caused by…
cell division problems
when fully saturated 1g Hb will bind __ml O2
1.34
how can you work out how much iron is in the blood
divide total blood volume by 2
storage iron is stored in a molecule called…
ferritin
circulating iron is bound to what molecule?
transferrin
what organ is iron stored in mainly?
liver
how does iron get to red cells?
circulate bound to transferrin
transferred to bone marrow macrophages
fed to red cell precursors
test for functional iron levels
Hb
test for transported iron levels?
serum iron OR transferrin
test for storage iron?
ferritin levels
what does transferrin transport iron from and to?
from macrophages/intestinal cells/hepatocytes to tissues expressing transferrin receptors eg erythroid marrow
low ferritin means…
iron deficiency
causes of iron deficiency
diet
blood loss eg menorrhagia/GI
malabsorption
men commonly get iron deficiency T or F
F, rare and usually pathological
how much iron is lost per month from menstrual blood loss? how is this worked out?
15-20mg
average period blood loss is 30-40ml and to get iron levels you divide blood vol by 2
heavy menstrual blood loss is defined as
> 60ml blood loss
when do epithelial changes such as skin and koilonychia occur in anaemia?
LATE
normal MCV values
85-105
normal transferrin sat is..
30%
what iron supplement is used? dose and frequency?
ferrous fumarate 210mg TDS
management plan for man with iron deficiency anaemia and bowel signs
colonoscopy
how should iron tablets be taken and why?
with food as it is absorbed very quickly
with orange juice as acidity transports it better
other iron preparations?
IV iron
risks of IV iron
risk of ROS
anaphylaxis
diabetes risk
how does iron get into the body?
as haem or non-haem iron
how much iron is absorbed per week?
7g
even if iron isnt raised after initiating supplements, what marker can you check to see if the patient is responding to treatment?
reticulocytes
how long should you treat pernicious anaemia?
for life as its an autoimmune condition
give B12 every 3 months
3 main SEs of iron supplementation
black stool
constipation
abdo pain
