Anaemia Flashcards
What is the definition of anaemia?
low haemoglobin concentration
What is the normal haemoglobin levels for males and females?
males - 130-180
females - 120-160
What are the pathophysiological classifications of anaemia?
decreased production
increased destruction or loss of red cells
What is the practical classifications of anaemia?
microcytic - decreased MCV
macrocytic - increased MCV
What are the symptoms of anaemia?
fatigue dyspneoa faintness palpitations headache tinnitus anorexia
What are the causes of microcytic anaemia?
haem deficiency:
- iron deficiency
- anaemia of chronic disease
- problems with porphyrin synthesis (v rare)
globin deficiency:
- thalassaemia
What is the most common cause of microcytic anaemia?
iron deficiency
What are some causes of iron deficiency?
blood loss e.g. menorrhagia, GI bleeding
poor diet (usually children/babies)
malabsorption e.g. coeliac
Describe iron deficient anaemia
microcytic
hypo chromic
How is iron deficiency anaemia diagnosed?
decreased ferritin
decreased Hb
What is the treatment of IDA?
treat the cause
oral iron e.g. ferrous sulphate
What are the side effects of oral iron?
GI disturbance: nausea, abdominal discomfort, diarrhoea/ constipation
black stools
By how much should Hb rise per week after starting treatment for IDA?
by 10g/L a week
What are the different classifications of macrocytic anaemias?
megaloblastic
nonmegaloblastic
What is a megaloblast?
a cell in which nuclear maturation is delayed compared with the cytoplasm
Which macrocytic anaemias are megaloblastic?
B12 and folate deficiency
Why are B12 and folate deficiencies megaloblastic?
As they are both required for DNA synthesis
Where is b12 absorbed?
terminal ileum
Describe B12 absorption.
binds to intrinsic factor in the stomach
absorbed into terminal ileum
Why is RBC production slow in B12 deficiency?
synthesis of thymidine and hence, DNA is impaired
What are causes of B12 deficiency?
dietary e.g. vegans
malabsorption e.g. pernicious anaemia
What is pernicious anaemia?
autoimmune condition with resulting destruction of gastric parietal cells
intrinsic factor deficiency resulting in B12 malabsorption and deficiency
What are causes of folate deficiency?
poor diet e.g. alcoholics, elderly
increased demand e.g. pregnancy, haemolysis
malabsorption e.g. coeliac
drugs, alcohol, anti epileptics
Where is folate absorbed?
jejunum
What can folate deficiency cause in pregnancy?
neural tube defects
What is the treatment of folate deficiency?
underlying cause
folic acid 5mg/day PO 4 months
never without B12 unless patient has known normal B12 levels (as if low B12 - can cause subacute combined degeneration of the cord)
What spinal cord problem can B12 deficiency cause?
subacute combined degeneration of the cord
What is the treatment of B12 deficiency?
treat underlying cause
malabsorption/pernicious - lifelong injections
dietary - oral
What are the causes of non megaloblastic macrocytic anaemia?
alcohol
liver disease
hypothyroid
What autoantibodies can you test for in suspected pernicious anaemia?
anti intrinsic factor (IF)
anti gastric parietal cell (gpc)
What neurological symptoms can B12 deficiency cause?
parasthesiae
peripheral neuropathy
