anemia Flashcards
s/s
Possible symptoms include:
- pallor
- fatigue
- dyspnoea
- anorexia
- headache
- bowel disturbance
- features of underlying disease
Possible signs include:
- koilonychia is suggestive of iron deficiency
- conjunctival pallor suggests anaemia (1)
- combination of fair or prematurely grey hair and blue eyes may indicate pernicious anaemia
- gum hypertrophy may occur secondary to infiltration by leukaemic cells, especially in acute monocytic leukaemia
- atrophic glossitis may occur in megaloblastic anaemia or iron deficiency anaemia
- tachycardia
- wide pulse pressure
- systolic ejection murmur
definition
Anaemia can be described as a reduction in the haemoglobin concentration to below 13.5 g per decilitre in an adult male and below 11.5 g per decilitre in an adult female.
The World Health Organization uses the following haemoglobin thresholds to define anaemia individuals living at sea level:
children
- 0.50–4.99 yrs - 11 g/dl
- 5.00–11.99 yrs - 11.5 g/dl
- 12.00–14.99 yrs - 12 g/dl
women
- non-pregnant women (≥15 yrs) - 12 g/dl
- pregnant women - 11 g/dl
men (≥15 yrs)
- 13 g/dl (1)
~~~
Men: 135-180 g/l Women: 115-160 g/l
classification
Anaemia is not a disease in itself, but may reflect an underlying disease process. It may also result from an increase in plasma volume and a dilutional effect - for example, as occurs during pregnancy.
It can be classified according to the blood film; thus red cells with a
- low mean cell volume (MCV) appear small and pale - microcytic;
- those with a large MCV appear large and oval shaped - macrocytic.
- Alternatively, the red blood cells may be normal in size and shape but may be reduced in number - normocytic.
classification by blood film
In adults:
microcytic anaemia - MCV < 76 femtolitres
normocytic anaemia - MCV = 76-96 femtolitres
macrocytic anaemia - MCV > 96 femtolitres
microcytic anemia
This is anaemia where the mean cell volume (MCV) is less than 76 femtolitres (normal range = 76-96).
The most common cause of microcytic anaemia is iron deficiency anaemia.
This shows a microcytic, hypochromic blood film with anisocytosis and poikilocytosis.
microcytic anemia causes
- iron deficiency anaemia - the commonest cause
- sideroblastic anaemia
- thalassaemia
- anaemia of chronic disease
- lead poisoning
- pyridoxine-responsive anaemia
normocytic anemia
This is anaemia where the mean cell volume is within the range of 76-96 femtolitres.
The most usual cause is anaemia of chronic disease
However, if there is a reduced white cell count or reduced platelet count then suspect bone marrow failure - diagnosis will require the performing of a bone marrow biopsy.
normocytic anemia causes
- acute haemorrhage
- haemolytic anaemia
- bone marrow failure
- anaemia of chronic disease
- mixed iron and folate deficiency
- pregnancy
- chronic renal failure
- riboflavin deficiency
macrocytic anemia
Macrocytic anaemias have a MCV > 96 femtolitres.
The commonest causes of macrocytic anaemia are vitamin B12 and folate deficiency, both of which cause megaloblastic haemopoiesis on the bone marrow examination.
Normoblastic haemopoiesis is seen in the other causes of macrocytic anaemia such as alcoholic liver disease, hypothyroidism and acute blood loss.
macrocytic anemia: causes w. normoblastic marrow
Macrocytic anaemia with a normoblastic bone marrow presents as round macrocytes on the blood film.
Possible causes include:
- alcohol
- liver cirrhosis
- reticulocytosis
- marrow infiltration
- hypothyroidism / myxoedema
- myleloproliferative disease
- myelodysplastic syndrome
- acquired sideroblastic anaemia
megaloblastic anemia
Common causes include:
- vitamin B12 deficiency
- folate deficiency
Rare causes include:
- inherited:
- orotic aciduria
- Lesch-Nyhan syndrome
- homocystinuria
- methylmalonic aciduria
- acquired:
- myelodysplasia
- metabolic inhibition by drugs:
- 6-mercaptopurine
- azathioprine
- ganciclovir
- aciclovir
- fluorouracil
- hydroxycarbamide (former British Approved Name, hydroxyurea)
- cytosine arabinoside
- cyclophosphamide
microcytic anemia- ix
- blood film - iron deficiency anaemia has a microcytic, hypochromic blood film showing anisocytosis and poikilocytosis
- serum iron, ferritin and total iron binding capacity:
- iron deficiency anaemia - low serum iron, low serum ferritin, raised TIBC
- other causes are iron loading conditions characterised by raised serum iron, raised ferritin, low total iron binding capacity
how to differentiate between diff types of hypochromic microcytic anemia
normocytic anemia ix algorithm
- The first investigation is the full blood count.
Is the reticulocyte count raised or normal/decreased?
🌸 causes of: normochromic normocytic anaemia with an elevated reticulocyte count include:
- haemolytic anaemia
- post-haemorrhage anaemia
normal or reduced reticulocyte count
🌸 In a patient with a normochromic normocytic anaemia and a normal/reduced reticulocyte count the following investigations should be undertaken:
- urea, creatinine and liver function tests
- endocrine screen for:
- thyroid funtion tests
- short synthACTHen test
- LH, FSH and sex steroids
- growth hormone and IGF-1 levels
- serum iron
