introduction to anaemia Flashcards
what is anaemia?
reduced total red cell mass
what is a surrogate marker of anaemia?
hemoglobin concentration
haematocrit
what level of Hb is considered anaemia in adult males?
Hb<130g/L
what level of Hb is considered anaemia in Adult females?
Hb <120g/L
where does red cell production take place?
in the bone marrow
measuring hemoglobin concentration using a spectrophotometric method involves ———- the red cells to create Hb solution
Stabilise the Hb molecules ———
Measure the optical density (OD) at ———-
- lyse
- cyan-metHb
- 540nm
what is Beer’s law?
OD proportional to the concentration
wat is calculated against a known reference standard cyan-metHb concentration solution?
Hb concentration
Hb concentration is calculated against known reference of?
standard cyan-metHb concentration solution
how to measure hematocrit?
it is a ratio/percentage of the whole blood that is red cells if the sample was left to settle
how do modern machines measure hematocrit?
by adding the calculated volume of the red cells it counts
in what situations are Hb/Hct not good markers of anaemia?
Rapid bleeds
Haemadilution
wat are the two pathophysiological classifications of anaemia?
decreased production
increased loss or destruction of red cells
when there is decreased production what is the reticulocyte count?
low reticulocyte count because you are not producing enough cells
when there is increased loss or destruction of red cells the reticulocyte count is?
increased because you are producing more cells to compensate the loss
hypo proliferative problems?
reduced amount of erythropoiesis , amount of production is a problem
maturation abnormalities?
present but ineffective erythropoiesis
cytoplasmic defects?
impaired haemoglobinisation
nucleus defects?
impaired cell division
what two states cause in increased loss or destruction of red cells?
bleeding
haemolysis
what is the difference between bleeding and hemolysis?
in bleeding no bilirubin present
why is there bilirubin present in hemolysis?
increase of breakdown products
if MCV iss low (microcytic) consider problems with?
haemoglobinisation
if MCV is hight (macrocyclic) consider problems with?
maturation
if MCV is normal consider problems with?
hypo proliferation
where is HB synthesized?
cytoplasm
to make Hb you need?
globins
Haem : porphyrin ring, Iron (Fe2+)
causes of microcytic anaemia?
commonest iron deficiency (low body iron)
what is the second commonest cause of microcytic anaemia?
thalassemia which is when there is a globin deficiency
shortage of globins and ham result in?
small red cells with a los Hb content
in microcytic anaemia the cells are——–and ———
microcytic and hypo chromic )small and lack in color)
some causes of microcytic anaemia of chronic disease occur because?
normal body iron but lack of available iron - most normocytic
very rare reasons of microcytic anaemia?
problems with porphyrin synthesis - lead poisoning, pyroxidine responsive anemias
another rare cause of microcytic anaemia?
congenital sideroblastic anaemia
what amount of iron is absorbed everyday?
1mg/day
what is the actual circulating iron in plasma?
4mg of iron in the pool
most of the iron in the body is as?
Hb
iron is stored in the body as?
ferritin
different in post-menopausal women and men is that?
don’t lose much blood, so can’t cope with loss of blood that well
when hemoglobin is fully saturated?
1gHb will bind 1.34mlO2
transferrin
picks up from storage area and takes it to tissues where it is required
transferrin saturation
is the amount of available iron
ferritin?
is a large intracellular protein
spherical protein stores up to?
4000 ferric ions
ferritin is also an ———– ——— reactive protein?
acute phase,
what is serum ferritin a measure of?
indirect measure of storage iron
low ferritin means?
iron deficiency
high ferritin?
could be falsely high
iron deficiency can be confirmed by a combination of?
anaemia (decreased functional iron) and reduced storage iron (low serum ferritin)
iron is absorbed from?
the proximal small bowel
what two conditions cause insufficient absorption of of iron?
coeliac disease
achlorhydria
red meat iron is absorbed much?
faster
examples of relative deficiency of iron?
women of childbearing age and children
what are examples of absolute deficiency of iron?
vegetarian diets
causes of chronic blood loss? (5)
Menorrhagia Gastrointestinal -Tumours -Ulcers -Non-steroidal anti-inflammatory agents Haematuria
what is average menstrual blood loss per month?
30-40ml/month = 15-20mg/month of iron
what is the average daily intake of iron?
1mg/day
heavy menstrual blood loss is?
> 60ml ie. >30mg iron/month
what are the sequential consequences of negative iron balance?
- Exhaustion of iron stores
- Iron deficient erythropoiesis
- Falling red cell MCV - Microcytic Anaemia
- Epithelial changes
- skin
- koilonychia
what is occult blood loss?
A small volume gastrointestinal blood loss can occur without any symptoms or signs of bleeding
what can occult blood loss cause?
This can outstrip the maximum dietary iron absorption of iron and result in anaemia
iron absorption can be increased by iron supplements
iron deficiency anaemia is a ——– not a ——–
symptom not diagnosis
what may relieve iron deficiency without treating the underlying problem?
iron replacement therapy
what may be curative of iron deficiency anaemia?
early GI surgery of tumors
what is the body’s natural response to anaemia?
increased red cell production- reticulocytes
what are reticulocytes?
red cells that have just left the bone marrow
what is the size of reticulocytes?
larger than average red cells
what is different amount reticule cites?
still have remnants of protein making machinery (RNA)
what color do reticulocytes stain?
purple/deeper red as a consequence
how does the blood film appear for reticulocytes?
polychromatic
how long does up regulation of reticulocyte production by the bone marrow take in response to anaemia?
a few days
what can automated analyses tell us about red cells?
Physical principles – e.g. cell size and light-scattering properties
what is the advantage of using automated analysers?
rapid and reproducible
what are measured red cell indices?
The haemoglobin concentration
The number of red cells (concentration)
The size of the red cells. (Mean Cell Volume or MCV)
what are the calculated indices of red cell indices?
Haematocrit
Mean cell haemoglobin
Mean cell haemoglobin concentration
what can blood films show?
look at acellular morphology
what can reticulocyte count show?
asses marrow response
