Lecture 6: Anaemia Flashcards Preview

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Flashcards in Lecture 6: Anaemia Deck (10):
1

What is anaemia?

Lower than normal haemoglobin for the age and sex of the patient

2

Classifications of anaemia?

1. Basic mechanism 

  • ineffective production 
  • impaired red cell survival

2. morphology 

  • small and pale 
  • large 

 

3

Causes of impaired production?

Deficiency of substances essential for red cell production

  • iron, vitamin B12, folate 

Genetic defect in red cell production 

  • thalassaemia 

Failure of bone marrow

  • Infiltration eg. leukaemia, irratiation or drug damage 

4

Reduced red cell survival?

Blood loss 

  • usually acute trauma or surgery 

Haemolysis

  • shortened survial of the red cell 
  • RBC being broken down = billirubin in excess = jaundice 

5

Morphological approach to anaemia?

Uses MCV, average Hb concentration and blood film comment

Microcytic hypochromic anaemia (MCV < 76) 

Normochromic normocytic anaemia (MCV 76-96) 

Macrpcytic anaemia (MCV >96)

 

(NB: Packed cell volume (PCV) or Haematocrit = % of red cell volume to total blood volume and basically mirrors the Hb)

6

Differential for Microcytic hypochromic anaemia?

  1. Iron deficiency - most common cause of anaemia 
  2. Chronic illness - iron block 
  3. genetic - thalassaemia (globin chains are insufficient) 

A image thumb
7

Diagnosis of Iron deficiency?

  • Measure serum iron, iron binding capacity (transferrin normally 30%) and iron saturation 
  • Measure Serum Ferritin 
  • Rarely examin iron stores in bone marrow 

8

classical patterns of iron deficiency vs anaemia of chronic disorder?

Iron deficiency shows a low serum ferritin but as iron is low the body produces iron transport protein so the trasnferrin % drops.

In anaemia of chronic disorder the serum ferritin is actually normal or elevated whist the serum iron is low along with a low iron transport protein. 

9

Causes of Iron Deficiency?

Diet 

  • eg. vegetarian 

Malabsorption (normally only absorb 1-2mg from 15 per day)

  • proximal small bowel 
  • coelaic 

Increased demands 

  • eg. pregnancy and breastfeeding

Chronic blood loss (Most clinically important) 

  • GI or GU tract 

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