Anaemia Flashcards
Causes of anaemia
- Increased plasma volume (pregnancy)
- Increased loss of RBCs
- Decreased production of RBCs
Symptoms of anaemia
- Fatigue
- Tinnitus
- Dyspnoea
- Faintness
- Palpitations
- Angina (pre-existing coronary artery disease)
- Headache
Signs of anaemia
- Pallor (conjunctiva)
- Tachycardia
- Ejection systolic murmur
- Cardiac enlargement
- Retinal haemorrhage
3 types of microcytic anaemias
- Iron deficiency
- Thalassemia (high serum iron + ferritin)
- Sideroblastic anaemia (very rare) (high serum iron + ferritin)
5 causes of normocytic anaemia
- Acute blood loss
- Anaemia of chronic disease
- Bone marrow failure
- Haemolysis
- Pregnancy
When to suspect marrow failure
- Low platelet + WCC
- ?Normocytic anaemia?
5 Causes of macrocytic anaemia
- B12 or folate deficiency
- Alcohol excess or liver disease
- Myelodysplastic syndromes
Causes of iron deficiency anaemia
- Blood loss (menorrhagia or GI bleeding)
- Malabsorption, coeliac disease
- Poor diet in children, unlikely in adults
- Hook worms, in the tropics (GI blood loss)
Signs of IDA
- Angular stomatitis
- Koilonychia
- Atrophic glossitis
What type of anaemia is IDA
Microcytic Hypochromic
Investigations for IDA
- Serum ferritin (?+serum iron?)
- Blood film
- Stool microscopy for ova (if hookworm suspected)
Rx of IDA
- Rx cause (menorrhagia COCP)
- Oral iron (ferrous sulphate)
Cause anaemia of the chronic disease (secondary anaemia)
Many
- Chronic infection
- Vasculitis
- Rheumatoid arthritis
- Malignancy
- Renal failure
Pathophysiology of secondary anaemia
- Poor use of iron in erythropoiesis
- Cytokine-induced shortening of RBC survival
- Reduced production of +response to erythropoietin
Investigations for secondary anaemia
- Blood film
- B12, folate and TSH levels
- Bilirubin?
- Serum LDH (Lactic dehydrogenase)?
- Coomb’s test?
Rx for secondary anaemia
- Rx underlying cause
- Erythropoietin
- Parenteral Iron
Causes macrocytosis
- Megaloblastic
- Non-Megaloblastic
- Other haematological disease
Most common type of macrocytic anaemia
Pernicious anaemia (Vit B12 deficiency)
Causes of Megaloblastic anaemia
- B12 deficiency
- Folate deficiency
- Cytotoxic drugs
Causes of non-Megaloblastic anaemia
- Alcohol excess, liver disease
- Hypothyroidism
- Pregnancy
Investigations of macrocytic anaemia
- Blood film
- Serum B12 and folate
- Bone marrow biopsy
- LFTs
Causes of folate deficiency
-Poor diet, alcoholics
-Increased demand (pregnancy, malignancy etc)
-Malabsorption (coeliac disease)
-Drugs
Phenytoin
Methotrexate
Sodium valproate
Trimethoprim
Rx for folate deficiency
- Rx underlying cause
- Folic acid 5mg/d po
How do we absorb Vit B12
Binds to intrinsic factor, absorbed at terminal ileum
Why does Vit B12 deficiency cause anaemia
- Reduced synthesis of thymine
- Therefore reduced DNA synthesis
- Therefore reduced RBCs synthesis
Causes of Vit B12 deficiency
- Dietary (vegans)
- Malabsorption
- Congenital metabolic errors
Why may there be malabsorption of Vit B12
- Gastrectomy (lack of intrinsic factor)
- Ileal resection
- Crohn’s disease
Symptoms of pernicious anaemia
- General anaemia symptoms
- Lemon skin (due to pallor + mild jaundice)
- Angular stomatitis
- Glossitis
- Dementia
- Degeneration of spinal cord
Cause of pernicious anaemia
- Autoimmune atrophic gastritis
- Leads to lack of gastric intrinsic factor excretion
Investigations for pernicious anaemia
- FBC
- Serum B12
- Blood film
- Parietal cell antibodies
What makes intrinsic factor
Parietal cells
Rx for pernicious anaemia
- Rx cause if possible
- If due to malabsorption then B12 injection are required
- If cause is dietary then oral B12 can be given
