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
What hereditary causes of haemolytic anaemia are there?
- Enzyme defects such as G6PD deficiency – X-linked disorder with haemolysis especially at night. Note avoid henna use.
- Membrane defects such as hereditary elliptocytosis, spherocytosis or ovalocytosis. Extravascular haemolysis
- Haemoglobinopathies such as Sickle Cell disease and thalassaemias
What are the clinical features of haemolytic anaemia?
Symptoms of Anaemia
Hypersplenism
Jaundice
What investigations should be done for someone you suspect of having haemolytic anaemia?
FBC – looking at Hb, red cell count, MCV and reticulocyte count
Blood film
Bilirubin – conjugated or unconjugated
Serum LDH – released from RBC when they die
What signs indicate intravascular haemolysis?
Haptoglobin – low (mops up free plasma Hb)
Methaemalbuminaemia – albumin bound to haem
Haemoglobinuria
Haemosiderin – storage of Hb in the kidneys leads to loss in the urine
What is the direct vs indirect coomb’s test?
Direct Coomb’s test – this test for antibodies bound to a patient’s RBC. This is different from the neonatal/blood transfusion test called the Indirect Coomb’s test which assesses for antibodies against RBCs.
What is aplastic anaemia?
Extremely rare disorder in which the bone marrow stops making cells causing a pancytopenia.
What are the clinical features of aplastic anaemia?
Anaemia
Leukopenia and infections
Thrombocytopenia and bleeding
What causes aplastic anaemia?
Autoimmune
Drugs
Viruses such as parvovirus, hepatitis
Irradiation
How should aplastic anaemia be investigated?
FBC
Blood film
Bone marrow biopsy
What management options are there for aplastic anaemia?
Supportive
Transfusion programme
Neutropenic regimen if counts below 0.5
Allogenic matched stem cell transplant if young enough
Immunosuppression with ciclosporin and antithymocyte globulin
How does pernicious anaemia present?
Presentation
Features of anaemia – lethargy, dyspnoea and pallor
Peripheral neuropathy – pins and needles and numbness typically symmetrical affecting the legs more than arms
Subacute combined degeneration of the cord
Neuropsychiatric features – memory loss, poor concentration, confusion, depression and irritability
Mild jaundice combined with pallor – lemon tinge
Glossitis
