Haematology Flashcards
what is anaemia
- low haemoglobin concentration, may be due either to a low red cell mass or increased plasma volume
- reduced production or increased loss of RBCs
symptoms of anaemia
- Fatigue
- Dyspnoea
- Faintness
- Palpitations
- Headache
- Tinnitus
- Anorexia
what are the ranges for anaemia in men and women
Low Hb is <135g/L for men and <115g/L for women
signs of anaemia
- May be absent
- Pallor
- Hyperdynamic circulation e.g. tachycardia, flow murmurs and cardiac enlargement
consequences of anaemia
-Reduced O2 transport
-Tissue hypoxia
-Compensatory changes:
>Increase tissue perfusion
>Increase O2 transfer to tissues
>Increase red cell production
pathological consequences of anaemia
- Myocardial fatty change
- Fatty change in liver
- Aggravate angina/ claudication
- Skin and nail atrophic changes
- CNS cell death (cortex and basal ganglia)
what is MCV and how does it separate the types of anaemia
- mean cell volume
- normal = 76-96 femtolitres
- low MCV = microcytic anaemia
- normal = normocytic
- high = macrocytic
what are the 3 causes of microcytic anaemia
- Iron-deficiency anaemia – most common cause
- Thalassaemia
- Sideroblastic anaemia – very rare
- anaemia of chronic disease is an example
what are 7 causes of normocytic anaemia
- Acute blood loss
- Anaemia of chronic disease
- Bone marrow failure
- Renal failure
- Hypothyroidism
- Haemolysis
- Pregnancy
examples of normocytic anaemia
- Aplastic anaemia
- Haemolytic – thalassaemia, sickle cell disease, G6PD
- Infections – malaria
- Haemorrhage
8 causes of macrocytic anaemia
- B12 or folate deficiency
- Alcohol excess – or liver disease
- Reticulocytosis
- Cytotoxics
- Myelodysplastic syndromes
- Marrow infiltration
- Hypothyroidism
- Antifolate drugs
examples of macrocytic anaemia
Megaloblastic
B12/folate deficiency
Pernicious anaemia
what can haemolytic anaemias be
- normocytic or macrocytic
investigations for anaemia
- FBC and film, reticulocyte count, U&E, LFT, TSH, B12, folate, ferritin
- B12 deficiency = intrinsic factor Abs, Shilling test, coeliac Abs, B12 replacement
causes of iron deficiency anaemia (IDA)
- blood loss (haemorrhage, GI bleeding, menorrhagia)
- poor diet or poverty
- malabsorption ( coeliac disease)
- hook worm causes GI blood loss in tropics
pathology of IDA
- inadequate iron supply so interrupts the final step in haem synthesis
signs of IDA
- Tiredness
- Often asymptomatic
- Rare – koilonychias, angular cheilosis and glossitis
tests for IDA
- Blood film: microcytic, hypochromic anaemia
- Decreased MCV, MCH and MCHC
- Low ferritin
treatment for IDA
- treat cause
- ferrous sulfate = oral iron = can cause nausea and diarrhoea
- use for at least 3 months
what is anaemia of chronic disease
- microcytic/normocytic
- Reduced Hb related to chronic inflammatory disorders, chronic infections and malignancy
pathology of anaemia of chronic disease
- inflammatory cytokines = reduce sensitivity of bone marrow to erythropoietin and lead to failed incorporation of iron into developing red cells
- arise from 3 problems = poor use of iron in erythropoiesis, cytokines shorten RBC survival, decreased production and response to erythropoietin)
causes of anaemia of chronic disease
- Chronic infection, chronic inflammatory disease or malignancy
- Vasculitis
- Autoimmune disorders - Rheumatoid
- Renal failure
tests for anaemia of chronic disease
- ferritin normal
- B12, folate, TSH and tests for haemolysis
treatment for anaemia of CD
-Treat underlying disease
-Erythropoietin (raise Hb levels)
Side effects: flu-like symptoms, hypertension, mild rise in platelet count
-IV iron (overcome functional iron deficiency)