anaemia Flashcards
general anaemia symptoms
- Tiredness, SOB, headaches
- Dizziness, palpitations
- Worsening of other conditions – angina, heart failure, PVD
- Pale skin, conjunctival pallor
- Tachycardia, raised respiratory rate
- Koilonychia – spoon shaped nails can indicate iron deficiency
- Angular chelitis – cuts at corner of mouth, iron deficiency
- Atrophic glossitis – smooth tongue due to atrophy of papillae, iron deficiency
- Brittle hair – iron deficiency
- Jaundice – haemolytic anaemia, slight like in pernicious
- Bone deformities – thalassaemia
- Oedema, hypertension + excoriations on skin – can indication CKD
reticulocytes
red cells that have just left bone marrow (immature)
larger than average red cells
still have RNA - stain blue
–> blood film appears “polychromatic”
what does a low reticulocyte count indicate?
decreased production
- hypoproliferative - reduced amount of erythropoiesis
- maturation abnormality - erythropoiesis present but ineffective
– cytoplasmic defects - impaired haemoglobinisation
– nuclear defections - impaired cell division
do WCC/platelet count
what does a high reticulocyte indicate?
increased loss or destruction of red cells
- haemorrhage - normal bilirubin
- haemolysis - high bilirubin
high vs low MCV
if MCV low (microcytic) consider problems with haemoglobinisation (cytoplasm)
if MCV high (macrocytic) consider problems with maturation (nuclear)
where does haemoglobin synthesis take place? what would problems with this result in?
cytoplasm of red cell precursors
- defects results in small cells
iron metabolism
closed system
tiny amount in circulation moving to/from storage site to being utilised
circulating iron is bound to transferrin
transferred to bone marrow macrophages that regulate iron uptake by transferrin receptor expression
they “feed” iron cell precursors
iron is stored in ferritin mainly in liver
test to assess function, transported and storage iron
functional - haemoglobin
transported - serum iron, transferrin, transferrin saturation
storage iron - serum ferritin
transferrin
a protein with 2 binding sites for iron
-> transports iron from donor tissues (macrophages, intestinal cells + hepatocytes) to tissue expressing transferrin receptors (Esp erythroid marrow)
measure of iron SUPPLY (not storage)
% saturation of transferrin with iron is a measure of iron supply - when is it increased/reduced?
reduced in iron deficiency
reduced in anaemia of chronic disease
increase in haemochromatosis
ferritin
large intracellular protein - spherical protein stores up to 4000 ferric ions
tiny amount of ferritin is present in serum
serum ferritin is easily measure but an INdirect measure of storage iron
- low ferritin = iron deficiency
how does ferritin levels respond to infection?
response to infection increases ferritin -> can give falsely reassuring results
how can iron deficiency anaemia be confirmed?
by a combination of anaemia (decrease functional iron) and reduced storage iron (low serum ferritin)
sequential consequences of negative iron balance
- exhaustion of iron stores - ferritin falls
- iron deficient erythropoiesis then starts - MCV falls
- anaemia then develops
- epithelial changes - late effects in other sites of chronic lack of iron
- skin, koilonychia, angular chelitis
causes of iron deficiency
insufficient dietary
- absolute def rare
- relative def - esp women of child bearing age due to periods
losing iron - usually blood loss (GI, menstrual, urinary)
malabsorption - uncommon
Increased iron requirements
o Kids during periods of rapid growth
o Pregnancy – demands from baby + increase plasma volume during pregnancy causes dilution
causes of chronic blood loss
menorrhagia
Gastrointestinal
o Tumours
o Ulcers
o NSAIDs
haematuria
menstrual blood loss
- average 30-40ml/month -> 15-20mg/month
- average daily intake 1mg/day
- iron status precarious
- heavy menstrual loss > 60ml -> >30mg/month
occult GI blood loss
small volume GI blood loss can occur without any symptoms or signs of bleeding – 5mls of blood a day would be 2.5mg iron + might go unnoticed
- this can outstrip the max dietary iron absorption + result in microcytic anaemia
physiological reaction to management of iron deficiency anaemia
most of total body iron is in Hb - ferrition (iron stores) will not rise till after Hb returns to normal
MCV will rise as new, well haemoglobinised red cells are made (reticulocytes)
rise in Hb is limited by the ability of marrow to upregulate production of red cells
- slower if ongoing blood loss elsewhere
iron deficiency management
review diet, improve gastric acidity
review other meds - anticoags, PPIs
ferrous sulphate, ferous fumaarate, ferrous gluconate
-> sodium feredetate for paeds
- best given on empty stomach
- irritant on gut is dose dependent
monitor response after 4-6 wks
- need to continue for 2-3 months to replenish stores after Hb improved
side effects of iron supplementation
constipation
nausea + vomiting
abdo pains
dark stools
-> can result in poor compliance
