Anaemia Flashcards
What is anaemia?
Having less than the normal amount of haemoglobin in the blood
What clinical features does anaemia present with?
Dyspnoea Weakness and lethargy Palpitations Headaches Angina, heart failure and claudication (usually with pre existing coronary artery disease) Pallor (pale) Tachycardia and murmur and tinnitus Koilonychia Angular stomatitis (iron and B12 deficiency raw and red at edge of mouth
What causes a low MCV anaemia?
Low MCV anaemia
• Iron-deficiency anaemia
• Thalassaemia, Spherocytosis and Elliptocytosis (MCV too low for the Hb and raised red cell count)
• Sideroblastic anaemia – ineffective erythropoiesis causing iron toxicity and anaemia
• Anaemia of chronic disease
What causes a normal MCV anaemia?
Normal MCV anaemia • Acute blood loss • Anaemia of chronic disease • Bone marrow failure • Renal failure • Hypothyroidism (also raised) • Haemolysis (also raised) • Pregnancy
What causes a high MCV anaemia?
High MCV anaemia • B12 or folate deficiency (and pernicious anaemia) • Alcohol excess or liver disease • Hydroxycarbamide • Myelodysplastic syndromes • Marrow infiltration
Is haemolytic anaemia high or low MCV?
Haemolytic Anaemia – can be low normal or high (due to lots of large reticulocytes). Causing pre-hepatic jaundice (so no bilirubin in the urine)
How should anaemia be investigated?
FBC
Haematinics – Folate B12, Ferritin, Transferrin, EPO and Total iron binding capacity
Blood film
Bone marrow aspirate and trephine biopsy
How is iron deficient anaemia managed?
Iron Deficiency Anaemia Assess and manage cause Bleeding - menorrhagia, GI bleed Poor diet or poverty (mostly babies not adults) Malabsorption – Coeliac’s disease
Treat underlying cause and give ferrous sulphate.
If this fails to correct the anaemia, then assess compliance – often causes GI upset in first few days and people stop taking. Also encourage they take with glass of orange juice.
What are the two types of macrocytic anaemia?
This can be
Megaloblastic – nuclear maturation is delayed compared to the cytoplasm – B12 and folate both of which are required for DNA synthesis
Non-Megaloblastic – alcohol excess, haemolysis and consequent Recticulocytosis, liver disease, hypothyroidism and pregnancy.
What foods is folate found in and why might is be low?
Folate – naturally found in green vegetables, nuts, yeast and liver
Reasons for it being low include: poor diet, increased demand – pregnancy, malabsorption (Coeliac’s) , alcohol and drugs such as antiepileptics.
How should folate deficient anaemia be managed?
Treat with 5mg/day of PO folate with B12, never give folate without B12 as otherwise you may precipitate subacute combined degeneration of the cord.
How should B12 deficient anaemia be managed?
Vitamin B12 – most people have stores of B12 that will last for 4 years. If low this could be due to diet (vegan), malabsorption and congenital metabolic disorders. Treat with B12 supplements.
What is pernicious anaemia and how is it managed?
B12 requires intrinsic factor to be absorbed. This is normally created in the stomach. In pernicious anaemia autoimmune atrophic gastritis destroys the cells that produce intrinsic factor or destroy intrinsic factor itself. Treat with IM B12 every other day for 2 weeks then 1mg IM every 3 months for life. Can also be due to malabsorption in which case give oral B12 after the initial IM doses.
What are haemolytic anaemias?
Premature breakdown of RBCs which can occur intravascular (circulation) or extravascular (reticuloendothelial system e.g. bone marrow, spleen and liver). May be asymptomatic unless the bone marrow can’t compensate.
What acquired causes are there for haemolytic anaemia?
- Immune mediated haemolytic anaemia which can be drug induced, autoimmune (AIHA), paroxysmal cold haemoglobinuria, or Isoimmune such as acute transfusion reactions or haemolysis of the new-born. Extravascular haemolysis
- Microangiopathic Haemolytic anaemia – mechanical damage to RBC which causes intravascular haemolysis e.g. Haemolytic uraemic syndrome, TTP, DIC, eclampsia and prosthetic heart valves.
- Infection – e.g. malaria
