Anaemia Flashcards
What is haemoglobin
- protein found in red blood cells. It is responsible for picking up oxygen in the lungs and transporting it to the cells of the body
- Made from iron
Causes of microcytic anaemia
T – Thalassaemia A – Anaemia of chronic disease I – Iron deficiency anaemia L – Lead poisoning S – Sideroblastic anaemia
Causes of normocytic anaemia
A – Acute blood loss A – Anaemia of Chronic Disease A – Aplastic Anaemia H – Haemolytic Anaemia H – Hypothyroidism
What is macrocytic anaemia
- can be megaloblastic or normoblastic
What is megaloblastic anaemia
- the result of impaired DNA synthesis preventing the cell from dividing normally
- Rather than dividing it keeps growing into a larger, abnormal cell.
- This is caused by a vitamin deficiency
Examples of a megaloblastic anaemia
B12 deficiency
Folate deficiency
Examples of a Normoblastic macrocytic anaemia
Alcohol Reticulocytosis (usually from haemolytic anaemia or blood loss) Hypothyroidism Liver disease Drugs such as azathioprine
What are the generic symptoms of anaemia
Tiredness Shortness of breath Headaches Dizziness Palpitations Worsening of other conditions such as angina, heart failure or peripheral vascular disease
Signs of specifically, iron deficient anaemia
- Pica: dietary cravings for abnormal things such as dirt
- Hair loss
Generic, systemic signs of anaemia
Pale skin
Conjunctival pallor
Tachycardia
Raised respiratory rate
peripheral stigmata of anaemia
- Koilonychia
- Angular chelitis
- Atrophic glossitis
- Brittle hair and nails
- Jaundice: haemolytic anaemia
- Bone deformities: thalassaemia
- Oedema, hypertension and excoriations on the skin: CKD
What investigations should you do to investigate anaemia
Haemoglobin Mean Cell Volume (MCV) B12 Folate Ferritin Blood film ? OGD/Colonoscopy for IDA ? bone marrow biopsy
Why do we need iron
- Bone marrow requires iron to produce Hb
- Iron is mainly absorbed in the duodenum and jejunum
Why might patients be iron deficient
- Insufficient dietary iron
- Iron requirements increase (e.g. pregnancy)
- Iron is being lost (e.g. slow bleeding from a colon cancer)
- Inadequate iron absorption
Why do PPIs and antacids cause iron deficient anaemia
- acid from the stomach keeps the iron in the soluble ferrous (Fe2+) form.
- When the acid drops it changes to the insoluble ferric (Fe3+) form so it can’t be absorbed
Causes of iron deficient anaemia
- Blood loss (most common cause in adults e.g. menorrhagia)
- Dietary Insufficiency (most common cause in growing children)
- Poor iron absorption (inflammation of bowel)
- Increased requirements during pregnancy
What is Total iron binding capacity (TIBC)
is directly related to the amount of transferrin in the blood which is the carrier protein for ferric ions (Fe3+)
What is Transferrin saturation
- good indication of the total iron in the body
- Normal adults about 30%
In iron deficient anaemia, what do transferrin levels & TIBC do
Increase
decrease in iron overload
What is ferritin
- form that iron takes when it is deposited and stored in cells
- marker of inflammation
- Low in iron deficient anaemia
What is a normal serum ferritin level
41 – 400 ug/L
What is a normal Total Iron Binding Capacity
45 – 80 μmol/L
What is a normal transferrin saturation
15 – 50%
What is the management of iron deficient anaemia
- If unclear cause OGD & colonoscopy If symptomatic: - Blood transfusion - Iron transfusion (avoid during sepsis, iron feed bacteria) - Oral iron: ferrous sulphate
How quickly does the Hb rise when treating an IDA
10 grams/litre per week.
What is Penicious anaemia
- Autoimmune vitamin B12 deficiency where antibodies are created against the parietal cells in the stomach which produce intrinsic factors which allows Vitamin B12 to be absorbed in the ileum
What neurological symptoms can a vitamin B12 deficiency cause
Peripheral neuropathy with numbness or paraesthesia (pins and needles)
Loss of vibration sense or proprioception
Visual changes
Mood or cognitive changes
Which autoantibodies should you test for if suspecting pernicious anaemia
- Intrinsic factor antibody: first line
- Gastric parietal cell antibody: can be tested but is less helpful
What is the management of Vitamin B12 deficiency due to dietary issues
oral replacement with cyanocobalamin
What is the management of pernicious anaemia
- 1mg of intramuscular hydroxycobalamin 3 times weekly for 2 weeks, then every 3 months
Why must you always treat a folate deficiency AFTER a vitamin B12 deficiency is treated, why?
Treating patients with folic acid when they have a B12 deficiency can lead to subacute combined degeneration of the cord.
What is haemolytic anaemia
- destruction of red blood cells (haemolysis) leading to anaemia
- Can be inherited fragility of RBC leading to faster break down (chronic haemolytic anaemia)
- Can be acquired increased break down of RBC
Example of inherited haemolytic anaemia
Hereditary Spherocytosis Hereditary Elliptocytosis Thalassaemia Sickle Cell Anaemia G6PD Deficiency
Examples of acquired haemolytic anaemias
Autoimmune haemolytic anaemia Alloimmune haemolytic anaemia (transfusions reactions and haemolytic disease of newborn) Paroxysmal nocturnal haemoglobinuria Microangiopathic haemolytic anaemia Prosthetic valve related haemolysis