CPT2: Anaemia 4 Flashcards
What is sideroblastic anaemia?
The body has Iron available but cannot incopperate it into the Hb
What type of anaemis is this based on morphology?
- If Hereditary (rare) - Microcytic
- If acquired (30% alcoholics) - Macrocytic
- Production of abnormal red blood cells which may evolve into haematological malignancies
- Nucleated erythroblasts with granules of
iron in the cytoplasm
What are the clinical manifestations in:
- Aquired
- Hereditary
Sideroblastic anaemia?
Hereditary Sideroblastic anaemia:
- Infancy or childhood
- Enlarged spleen
- Mild thrombocytopenia
Acquired Sideroblastic anaemia:
- Middle age
- Asymptomatic
- Can evolve into haematological malignancies (leukaemia)
- Linked to Vit B6/copper deficiency
Levels – high or low?
- Fe levels?
- Ferritin levels ?
- Transferrin Saturation?
- Vit B6 levels?
- What is vit B6 also known as?
- High
- Hight
- Low
- Low
- Pyridoxine
What investigations are the following results of investigation:
- Eythrocyte size
- Haemolglobin
- Serum ion
- Serrum Ferritin
Treatment for sideroblast anaemia?
What Counselling points
Treatment:
- Pyridoxine 400mg daily
- •Long term lower maintenance dose (high dose causes peripheral neuropathy)
Counselling:
- Rarely reversible
- Pyridoxine may take months
- Do not buy OTC vitamin supplements
What is haemolytic anaemia?
•Anaemias caused by haemolysis
What causes haemolytic anaemia? What is the epidemiology?
Epidemiology/ Aetiology
- Sickle cell anaemia
- Hereditary
- Found in ethnic groups living in the tropics
- UK ~5000 people, mainly Afro-Caribbean’s
Patients with sickle cell trait are more resistant to malaria in childhood. This selective survival advantage explains the high incidence in equatorial countries
What is the prevalance of sickle cell disease?
What is used to detect it?
- Infant screening programmes
- 1 in every 2000 live births, 350 babies born with SCD annually (England)
- Most common genetic disorder at birth (NHS screening programme 2011)
•
- Highest prevalence – black African & black Caribbean
- Population migration, history of malaria or migration from malaria area
- Clinical practice in most countries
- Improved:
- median age of death – M 42yrs, F 48Yrs, (Platt et al 1994)
- improved management of infections
- childhood complications
- new interventions, active health lifestyles, counselling
•Estimated 90% will survive past 20yrs of age (BMJ Best practice 2016)
What is sickle cell disease?
What does it cause?
In Sickle cell disease, Sickle Hb has an abnormal beta-globin chain that distorts the erythrocyte into a sickle shape (Hb S). This distorted shape of erythrocytes means they do not flow as freely through the blood vessels
The deformed erythrocytes can form clusters and block blood vessels leading to damage of small & large vessels. They can also sequestered in Liver & spleen and cause anaemia. This leads to intense pain, life threatening infections and chronic organ damage
Sickle cell crisis – Intense pain caused by blockage and infarction of blood vessels leading to ischaemic tissue, inflammation and pain
What is the lifespan of a RBC?
120 days
How is sickle cell anaemia developed?
What is the lifespan of sickle cells
What are Hb levels?
- If Hb S is inherited from both parents (homozygous) = Hb SS
- Sickle cell anaemia - Most severe from of Sickle cell disease
- Sickle cell lifespan: 16-20 days Vs 120 days in normal erythrocytes
- Hb levels typically 6-8g/dL
- Chronic anaemia can be well tolerated, no treatment may be needed
What are clinical signs and symptoms of Sickle cell anaemia?
What are precipitating factors of sickle cell crisis?
- Chronic anaemia
- Arthralgia
- Anorexia
- fatigue,
- Splenomegaly
- severe pain
Sickle cell crisis - precipitated by fever, dehydration, hypoxia and acidosis.
Sickling of erythrocytes and acute complications more likely when…?
Sickling of erythrocytes & Acute complications more likely when:
- Reduced blood Oxygen; exertion, high altitude, anaesthesia
- Under psychological stress, illnesses
- Cold temperatures
- Dehydration
- Pregnancy à complications (miscarriage, still birth, UTI’s, chest crisis, thromboembolic eventsàmaternal death
What are chronic complications?
Chronic complications
Due to repeated infarction & vascular occlusion
- Acute stroke – sickle cell most common cause of ischaemic stroke in children
- Acute priaprism
- Gall stones
- Epilepsy…
- Renal complications – renal failure, dilute urine —> dehydration, Nocturnal Enuresis
- Chronic pain – (leg ulcers, poor microvascular blood flow & poor oxygenation by sickle cells)
- Chronic anaemia
What infections are patients with SC anaemia likely to get?
What is important to include in regards to treatment
- Life threatening infections- splenic dysfunction —> immune system less able to clear circulating antigens
- Common chronic infection – osteomyelitis
- Common childhood infection – pneumococcal infections in under 5’s
- Common acute infection - respiratory tract and septicaemia
- Lifelong antibiotic prophylaxis
- Vaccination programme
What is Thalassaemia?
What are common characteristics?
An inherited blood disorder. The inherited genes detemrine the severity. It is characterised by low Hb levels. It can be the a or B chain of HB affected.
- b – thalassaemia: Mediterranean population. North and West Africa, middle east and India – tends to be severe anaemia
- a- thalassaemia: more common but mild anaemia
Characteristics:
- Increase in erythropoeitin production
- expansion of the bone marrow
- bone deformity
- growth retardation
- splenomegaly
Bone defomity of face/ skull: The bone marrow expands and bones become wider, thinner and more brittle. As they are more brittle there is more chance of osteoporosis
What investigations should be carried out for haemolytic anaemia?
Sickle cell anaemia:
- Hb – low or normal
- Blood film - visual characteristics
- Serum ferritin – low and normal
Thalassaemia:
- Hb – low
What are goals of theapy?
- Identify underlying cause
- Reduce symptoms
- Prevent crisis
- Improve QOL
What is the treatment for siickle cell anameia?
- Sickle cell anaemia – self/care management plan
Prophylaxis:
- Adults:Phenoxymethylpenicillin 250mg bd
- Children under 1yr: 62.5 mg bd
- Penicillin allergy? - oral erythromycin
- Haemophilus influenza vaccine
- Pneumococcal polysaccharide vaccine (PPV) /5yrs
- Hep B vaccine
- Folic acid supplementation – pre-conception/pregnancy - 5mg daily
- Anti-malarials – importance of adherence if travelling
Crisis treament
Treatments for Stem cell anam
Thalassaemia
CSD Stem cell transplantation
- The only potentially curative treatment
- Recommended in children - under 17yrs
- Matched sibling donor required for success
Thalassaemia
- Currently no effective treatment available
- Bone marrow transplant, Blood transfusion,
- folic acid daily 5mg, splenectomy
Cousneling points
- Encouragement for prophylactic penicillin and folic acid in sickle cell anaemia
- Opioid addiction is possible due to severely painful nature of sickle cell crisis
- counsel on non-pharmacological methods of pain relief
- Always inform healthcare professionals before taking anything OTC/Herbal etc – due to interactions/Contra-indications
