Anaemia

The most popular video on our site! Nearly all you will ever need to know about anaemia.

 

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Video Duration: 52 minutes

  • Sickle Cell
    Created by EveRobertson
    General
    Epidemiology

    Haemoglobinopathy

    Prevalence 1 in 2000 live births

    Most commonly affected: African, Caribbean and Middle Eastern ethnic backgrounds

    Those with Northern European ethnic background have low prevalence

    Pathology

    HbS - codon 6 of Hb gene. Glutamine to valine substitution --> insoluble at low O2 tensions --> blood vessel occlusion --> ischaemia

    HbSS: Sickle cell anaemia

    HbAS: Sickle cell trait

    Some patients have increased HbF which reduces the disease severity

    Infection, dehydration and hypoxia precipitate sickling

    Increased susceptibility to infection: pneumococci, Haemophilus influenza +salmonella (encapsulated organisms)

    Top three causes

    None

    Clinical Features
    Symptoms

    General: abdominal pain (gall stones), jaundice, fatigue (anaemia).

    Painful crises: acute chest* (chest pain, non-productive cough), bone pain, hand-foot syndrome (dactylitis - swelling and pain of the fingers), priapism

    *differential is LRTI

    Signs

    General: Splenomegaly, anaemia, jaundice, neurological signs (stroke 1 in 10), retinopathy, leg ulcers.

    Specific: salmonella osteomyelitis

    Painful crises may be precipitated by: dehydration, cold environment, hypoxia

    Late: cardiomegaly (chronic anaemia), heart failure, stroke


    Investigations
    Cultures

    Urine dip (?nephritis)

    Blood cultures in acute presentation

    Bloods

    Hb electrophoresis and sickle solubility tests

    FBC (?anaemia, ?infection in acute presentation)

    U+Es (?nephritis)

    Folate level (?folate deficiency)

    Imaging

    CXR (in acute chest)

    Scopic/Biopsy

    None

    Functional

    None

    Treatment
    Conservative

    General: keep warm, keep hydrated especially before exercise, careful with extreme exercise

    Crisis: Oral or IV analgesia PRN, keep patient warm, high flow oxygen if sats are low, IV and oral fluids PRN

    Medical

    Screening: Guthrie heel prick test. Can carry out chorionic villus sampling in high risk parents.

    General: OD folic acid, vaccinations, penicillin prophylaxis. Hydroxyurea can increase the amount of HbF and therefore improve oxygen sats.

    Crisis: exchange transfusion in acute chest syndrome and priapism

    Bone marrow transplantation is reserved for repeat admission in a child with an HLA-matched sibling

    Surgical

    None

  • Thalassaemia
    Created by Eimear McClenaghan
    General
    Epidemiology

    Imbalanced alpha beta chain production.

    Pathology

    Both thalassaemias result in ineffective erytgropoeisis, resulting in haemolysis.


    Alpha Thalassaemia

    • genetic deletions
    • overproduction of beta chains


    Beta Thalassaemia

    • point mutations
    • over production of alpha chains

    Top three causes

    Alpha Thalassaemia

    • genetic deletions resulting in impaired reduction of 1, 2, 3 or all 4 of the alpha globin genes leading to a relative excess of beta globin chains (or gamma globin chains in the new born)
    • the excess beta chains form unstable tetramers (HbH) which have abnormal oxygen dissociation curves
    • the excess gamma chains form tetramers which are poor carriers of O2 as their affinity for O2 is too high and so is not dissociated in the periphery
    • the degree of impairment corresponds to which clinical phenotype is present - I.e. how many genes are affected
    • 4 X Alpha genes affected - alpha thalassaemia major: not compatible with life (hydrops fetalis), fetuses are edematous and require intrauterine transfusions at 18-25 weeks with chronic transfusions or bone marrow transplants after brith
    • 3 X Alpha genes affected - haemoglobin H disease: two unstable Hbs are present -/- -/a; Hb Barts (tetrameric gamma chains) and Hb H (tetrameric beta chains); microcytic hypochromic anaemia with target cells and Heniz bodies on Hb H as well as hepatosplenomegaly.
    • 2 X Alpha genes affected - alpha thalassaemia minor: genotype -/-, a/a or -/a, -/a is mild hypochromic anaemia and often associated with iron deficiency; alpha-thal-1 which is a cis deletion of both genes on one chromosome is associated with Asians, whereas alpha-thal-2 is a trans deletion of one gene on each chromosone and is associated with Africans
    • 1 X Alpha genes affected - alpha thalassaemia minima: genotype -/a, a/a is enough to produce normal function


    Beta Thalassaemia

    • point mutations causing
    • Thalassaemia Major Cooley's Anaemia (homozygous) occurs when both alleles have point mutations, this is a severe microcytic, hypochromic anaemia that causes compensatory extramedullary haematopoesis (hepatosplenomegaly and bony expansion - frontal bossing), presents at 3-6months and requires chronic transfusions
    • Thalassaemia Intermedia
    • Thalassaemia Minor (heterozygous) only one allele bears a deletion so individuals will suffer microcytic anaemia
    Clinical Features
    Symptoms

    Alpha Thalassaemia

    • alpha thalassaemia major: not compatible with life (hydrops fetalis), fetuses are edematous and require intrauterine transfusions at 18-25 weeks with chronic transfusions or bone marrow transplants after birth
    • haemoglobin H disease: microcytic hypochromic anaemia and hepatosplenomegaly.
    • alpha thalassaemia minor: mild hypochromic anaemia and often associated with iron deficiency; alpha-thal-1 is associated with Asians, whereas alpha-thal-2 is associated with Africans
    • alpha thalassaemia minima: is enough to produce normal function


    Beta Thalassaemiaa

    • Thalassaemia Major severe microcytic, hypochromic anaemia that causes compensatory extramedullary haematopoesis (hepatosplenomegaly and bony expansion - frontal bossing), presents at 3-6months and requires chronic transfusions
    • Thalassaemia Intermedia need transfusions at times of illness
    • Thalassaemia Minor mild microcytic anaemia
    Signs

    None

    Investigations
    Cultures

    Blood film

    • all thalassaemias are microcytic anaemias
    • HbH will show target cells with Heinz bodies
    Bloods

    Blood film

    • all thalassaemias are microcytic anaemias
    • HbH will show target cells with Heinz bodies
    Imaging

    None

    Scopic/Biopsy

    None

    Functional

    None

    Treatment
    Conservative

    None

    Medical

    Transfusions

    Surgical

    Splenectomy for Thalassaemia Beta Major and Haemoglobin H disease

  • Iron Deficiency Anaemia
    Created by Eve Fordyce
    General
    Epidemiology

    Anaemia is a haemoglobin less than the reference range set for the individual.

    Women <11.5g/dl

    Men <13.5 g/dl

    Iron deficiency anaemia is the most common form of anaemia world wide and it is estimated that between 2-5% of men and postmenopausal women In the developed world suffer from it.

    Pathology

    Iron deficiency anaemia is due to having insufficient supplies of iron to maintain adequate RBC production.


    Top three causes

    IDA can be due to multiple underlying causes, such as:

    1. Reduced iron intake, This is fairly uncommon, but may occur with unorthodox diets such as veganism.

    2. Malabsorption from the duodenum, this can occur on coeliacs

    3. Increased demand for iron, for example in pregrancy.

    4. Prolonged blood loss. ( just 10ml a day can lead to IDA)

    The last is the most common cause, with pathology in the GI tract and the uterus (in menstruating women) being the most common site of blood loss.


    Clinical Features
    Symptoms

    Largely anaemia will be asymptomatic.

    However, where there is a chronic underlying condition the symptoms of this may be worsened.

    Symptoms, when present, include:

    lethargy, breathlessness, angina, peripheral oedema, headache, tinnitus and sore tongue/taste disturbances, rarely dysphagia.

    Signs

    The most common sign is pallor of the conjunctivae, other things that may be visible are:

    koilonychia (spooning of the nail),

    angular stomatitis (fissures around the oral cavity),

    atrophic glossitis (smooth, and beefy tongue) ,

    In severe cases may have a flow murmur, or a compensatory tachycardia.

    Consider also, that it might be worthwhile performing an abdominal examination to look for palpable masses, and a rectal exam to look for visible bleeding. These types of examination are important because anaemia is not an end diagnosis and the underlying cause must be found.

    Investigations
    Cultures

    None

    Bloods

    Venous: Full blood Count, Blood Film, MCV, serum ferritin and binding capacity

    Imaging

    None specific to diagnosing anaemia, if suspect abdominal pathology may request, ultrasound, x-ray, Barium enema etc.

    Scopic/Biopsy

    None specific to anaemia, may be required for diagnosing underlying cause of anaemia.

    Functional

    None

    Treatment
    Conservative

    None

    Medical

    Largely patients are treated with ferrous sulphate, which is given orally.

    However, in some people it is not tolerated due to severe side effects. In these cases can consider giving it parenternally.

    In haemorrhage situations patients may require a transfusion of blood products to stabalise them initially.

    Surgical

    None