Anaemia Flashcards
At what haemoglobin level is anaemia defined?
Men: <135
Women: <115
What are the main broad categories of causes for anaemia?
- Decreased production of RBCs
- Increased loss of RBCs
- Increased plasma cell volume
What are the clinical features of anaemia?
- Pallor
- Fatigue
- Shortness of breath
- Tinnitus
- Flow murmurs in severe cases
How can one classify anaemias?
According to the mean cell volume:
- Microcytic
- Normocytic
- Macrocytic
Name causes of microcytic anaemia
- Iron deficiency
- Anaemia of chronic disease (can be normocytic)
- Sideroblastic anaemia
- Thalassaemia
Name causes of normocytic anaemia
- Acute blood loss
- Anaemia of chronic disease (can be microcytic)
- Bone marrow failure
- Renal failure
- Hypothyroidism
- Pregnancy
Name causes of macrocytic anaemia
- B12 or folate deficiency
- Cirrhosis (alcohol excess or liver disease)
- Myelodysplastic syndromes
- Antifolates
- Hypothyroidism (can be normocytic)
- Reticulocytosis
Describe iron deficiency anaemia in regards to its cause, symptoms and signs on investigation.
How do you treat it?
Cause:
- Bleeding until proven otherwise
- Increased use/decreased intake/decreased absorption
- Haemolysis
Symptoms:
- symptoms of anaemia, brittle hair and nails
Signs:
- Microcytic, hypochromic anaemia, pencil cells
- Low iron, higher TIBC, low ferritin
Treatment:
- Investigate cause
- Give oral iron (IV if severe)
Describe anaemia of chronic disease in regards to its cause, symptoms and signs on investigation.
Cause: inflammatory markers inhibit EPO synthesis.
- Chronic infection
- Vasculitis
- Rheumatoid arthritis
- Malignancy
Symptoms:
- Symptoms of anaemia and cause
Signs:
- Low iron, low TIBC, higher ferritin
Describe sideroblastic anaemia in regards to its cause, symptoms and signs on investigation.
How do you treat it?
Cause: ineffective erythropoiesis
- Myelodysplastic syndromes
- Chemotherapy
- Alcohol excess/lead excess
Symptoms:
- Symptoms of anaemia and cause
Signs:
- Ring sideroblasts in the marrow
- High iron, normal TIBC, high ferritin
Treatment:
- Remove the cause
- Give pyridoxine
How can you differentiate between causes of macrocytic anaemia?
Megaloblastic anaemia:
- Hypersegmented polymorphs
- Leucopenia
- Thrombocytopaenia
- Anaemia
Name some causes of megaloblastic macrocytic anaemia?
- Vitamin B12 deficiency
- Folate deficiency
- Cytotoxic drugs
Name some causes of non-megaloblastic macrocytic anaemia
- Alcohol (most common)
- Reticulocytosis
- Pregnancy
- Liver disease
Where is vitamin B12 obtained by the body? What can cause a vitamin B12 deficiency? What are the clinical features of a vitamin B12 deficiency, and how do you treat it?
Mainly obtained from meat and dairy products, but there is a large body store.
Vitamin B12 deficiency is usually caused by dietary inefficiency or malabsorption due to a lack of intrinsic factor (pernicious anaemia), or a lack of a terminal ileum (resection for GI disease).
The clinical features include anaemia, glossitis, CNs disturbances (irritability, depression, peripheral neuropathy).
Vitamin B12 deficiency is treated by replenishing the stores with IM hydroxycobalamin.
Where is folate obtained by the body? What can cause a folate deficiency? What are the clinical features of a folate deficiency, and how do you treat it?
Folate is mainly obtained in the diet from green vegetables, and liver. There are generally low body stores.
Deficiency is usually due to poor diet, increased demand (pregnancy, increased cell turnover), malabsorption (coeliac disease) or drugs (alcohol, methotrexate, phenytoin).
The clinical features include anaemia.
To treat, oral folic acid is given. If the cause is unknown, vitamin B12 deficiency must be ruled out as folate can exacerbate the effects of the neuropathy.
