Anaemia Flashcards
What is Anaemia?
A low level of haemoglobin in the blood (an = without, emia = blood)
What is an essential component in creation of the haemoglobin molecule?
Iron
What is the diagnostic criteria for anaemia?
FBC - look for low levels of haemoglobin
Women = <120g/l
Men = <130-180g/l
MCV = 80-100Fl
What type of anaemia would you have if you had a MCV of less than 80?
Microcytic
What type of anaemia would someone have if they had a MCV of 80-100?
Normocytic
What type of anaemia would someone have if they had a MCV of over 100?
Macrocytic anaemia
What are the causes of microcytic anaemia?
- Thalassaemia
- Iron dificiency
- Chronic disease
What is the most common cause of microcytic anaemia?
Iron deficiency
What are the causes of normocytic anaemia?
A – Acute blood loss A – Anaemia of Chronic Disease A – Aplastic Anaemia H – Haemolytic Anaemia H – Hypothyroidism
What are the two categories of macrocytic anaemia?
Megaloblastic or normoblastic.
What can cause megaloblastic anaemia?
B12 or folate deficiency
What are the causes of normoblastic microcytic anaemia?
Alcohol excess or reticulocytosis or hypothyroidism or liver disease
What are some non-specific symptoms of anaemia?
- Tiredness
- SOB
- Headaches
- Dizziness
- Palpitations
What are some anaemia symptoms that are specific to iron deficiency anaemia?
- Pica
- Hair loss
- Coilinica (spooning of the nails)
- Brittle hair and nails
What are some generic symptoms of anaemia?
- Pale skin (Pallor)
- Conjunctiva pallor
- Tachycardia
- Raise RR
What is a symptom specific to haemolytic anaemia?
- Jaundice
What investigations would you do in someone you suspect to have anaemia?
- Hb
- MCV
- B12 and folate level
- Ferritin level
- Blood film to look for abnormal inclusions in the blood
What are the situations in which iron stores in the body can be used up causing the patient to become iron deficient and therefore struggle to create haemoglobin?
- Insufficient dietary iron
- Slow bleeding resulting in iron loss
- Increased demand of iron e.g in pregnancy
- Inadequate iron absorption in the GI tract
Where is iron absorbed?
In the duodenum and the jejunum
How does the stomach acid play a part in iron absorption?
It changes iron into its soluble form (ferrous Fe2+)
How can proton pump inhibitors lead to iron deficiency?
They lower the stomach acid so iron isn’t converted into soluble ferrous and therefore not absorbed
What can cause inadequate iron absorption in the GI tract?
Inflammation of the duodenum or jejunum i.e in coeliac disease of IBD
What is the most common cause of iron deficiency anaemia?
Blood loss e.g from a heavy menstrual period or from a GI source like a gastrointestinal cancer
What is the most common cause of iron deficiency in children?
Increased demand due to growing
What is the most common source of blood loss in non menstruating women and in men?
Gastrointestinal bleeding e.g through a cancer
What is total iron binding capacity?
Basically means the total space on the transferrin molecules for the iron to bind. So total iron binding capacity is directly related to the amount of transferrin in the body
What is the form that iron takes when it is store in cells?
Ferritin
Why is serum iron on its own not a useful measure?
Because the serum iron fluctuates throughout the day. For example, it is higher in the morning and after eating a meal containing foods high in iron
What happens to the total binding capacity and transferrin levels in iron deficiency?
They increase.
What is the normal serum ferritin?
40-100
What is the normal total binding capacity?
45-80
How do you manage iron deficient anaemia?
Treating the underlying cause
- Blood transfusions (this will immiedetly correct the anaemia but not the iron deficiency so it will come back)
- Iron infusion
- Oral iron e.g ferrous sulphate 200mg 3 x a day
What are the side effects of oral iron?
Constipation and black stools
What is pernicious anaemia?
A cause of B12 deficiency anaemia
What is pernicious anaemia?
A cause of B12 deficiency anaemia.
An autoimmune disease where antibodies are formed against the parietal cells in the duodenum causing decrease intrinsic factor and therefore insufficient B12 absorption.
What is the management of pernicious anaemia?
Dietary insufficiency can be corrected using oral supplements but in pernicious anaemia oral replacement is inadequate because the problem is absorption. They can be treated with 1mg of intramuscular hydroxycobalamin 3 times weekly for 2 weeks, then every 3 months.
What is haemolytic anaemia?
Where there is destruction of RBC’s (haemolysis) which leads to a low Hb count which is called anaemia.
What are the 5 inherited haemolytic anaemias?
- Hereditary Spherocytosis
- Hereditary Elliptocytosis
- Thalassaemia
- Sickle Cell Anaemia
- G6PD Deficiency
What are 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
What is the presentation of haemolytic anaemia?
- Anaemia - due to the reduction in circulating red blood cells
- Splenomegaly - as the spleen becomes filled with destroyed red blood cells
- Jaundice - as bilirubin is released during the destruction of red blood cells
What investigations would you do if haemolytic anaemia is suspected?
- Full blood count shows a normocytic anaemia
- Blood film shows schistocytes (fragments of red blood cells)
- Direct Coombs test is positive in autoimmune haemolytic anaemia
What is Hereditary Spherocytosis?
It is an autosomal dominant condition. It causes sphere shaped red blood cells that are fragile and easily break down when passing through the spleen.
