Anaemia: General Concepts and Iron Flashcards
What are the symptoms of anaemia?
Tired
Dizziness
lethargy
Shortness of breath
Headache
Tachycardia
Older people: heart failure and chest pain
Infants irritable and failure to thrive
What are the signs of anaemia?
Paleness
Increased CO (tachycardia and heart murmur)
Specific types of anaemia:
Jaundice (haemolytic anaemia and megaloblastic anaemia)
Koilonycha (spoon shaped nails)
Splenomegaly (especially in haemolytic anaemia)
Stool colour change
How is anaemia investigated?
A mean cell volume and blood film (MCV-mean cell volume)
What must be known before commencing treatment of anaemia?
The cause must be known
What is the factor looked at when making a diagnosis of anaemia?
Mean Cell Volume (MCV)
What stain is used for microscopic investigation of RBCs?
Romanovsky stain
What is investigated on stained blood film?
RBC morphology as well as other cell types for abnormalities
What other tests are guided by results of stained blood film?
Iron
Folate
Vitamin B12
Hb electrophoresis
What are the causes of anaemia?
Reduced BM production
Increased RBC loss
What are the causes of primary reduced bone marrow production?
BM failure: aplastic anaemia (bone marrow just doesn’t make RBCs usually after infection)
Red cell aplasia
Bone marrow dysfunction: myelodysplasia (in older people abnormal production of blood it is a preleukeumic situation.)
What are the causes of secondary reduced bone marrow production?
Insufficient nutrients: iron, folate, vitamin B12, EPO
Infection
Drugs
Marrow infiltration: leukaemia and cancer
What causes increased RBC loss?
Blood loss:
Acute incident which causes blood loss.
Chronic slow bleeding usually gastrointestinal (cancer; ulcer) or menorrhagia. May be secondary to anticoagulant drugs
Haemolysis: (premature RBC breakdown)
Inherited
Acquired
Defect of the cell or environment
Clinical clues to cause of blood loss?
Blood loss:
Menorrhagia
Malaena
Splenomegaly:
Chronic haemolysis
Extramedullary haemopoiesis
Bone marrow failure:
Bruising/bleeding or infection
Jaundice: Haemolysis
What is menorrhagia?
Abnormal bleeding during menstruation
What is malaena?
Production of dark sticky faeces containing partly digested blood as a result of internal bleeding
What is chronic splenic haemolysis?
Slow breakdown of RBCs in the spleen
What is normal MCV?
Normal MCV is 80 - 100 femtoliters, anything less is microcytic anaemia and anything larger is macrocytic
What anaemia is caused by lack of iron?
Iron deficiency microcytic anaemia
What anaemias are caused by microcytic ferritin normal/increased anaemia?
Thalassemia
Sideroblastic anaemia
Anaemia of chronic disease
What are the causes of macrocytic anaemia? What type of macrocytic anaemia do they cause?
Vitamin B12 and folate deficiency.
Low reticulocytic megaloblastic anaemia
What type of disorders cause normocytic anaemias?
Haemolytic anaemias as well as renal failure
Which cells of the body contain iron?
All cells in various amount.
2/3rds to 3/4ers in blood
What is iron important for?
RBCs
Myoglobin
Enzymes (cytochrome system in mitochondria)
Immune system
What is normal iron content in body?
4000mgs
What is normal iron content for RBCs?
2500mgs
What is normal iron content for myoglobin?
300mgs
What is normal iron content for enzymes?
200mgs
What is normal amount of iron for storage? Where does this storage take place
1000mgs (in liver, spleen, and bone marrow)
What happens to the iron in RBCs after 120 days?
It is absorbed by macrophages and released to transferrin as needed.
Where is excess iron stored?
In macrophages and in the liver as ferritin
Where is iron typically lost?
Skin, gut, sweat - 1mg/day
Menses 1mg/day
What causes iron deficiency?
Poor intake/absorption
Increased blood loss or utilization
Who typically has low iron intake?
People of developing world
Most common form of Anaemia in paediatrics
What causes poor iron absorption?
Stomach or bowel:
Gastrectomy
Coeliac disease
What causes chronic blood loss?
GI problems: ulcers, carcinoma, varices, diverticulosis, haemorrhoids
Uterine bleeding (menorrhagia)
What causes increased iron utilization?
Neonates
Puberty
Pregnancy (3mg/day required)
What causes iron deficiency in ages 1 - 5 years?
Nutrition
What causes iron deficiency in ages 5 - 15 years?
Increased utilization / growth
What causes iron deficiency in ages 15 - 40 years?
Mestruation and pregnancy in females
Coeliac’s disease in males causes malabsorption
What causes iron deficiency in ages >40 years?
GI blood loss
What are the stages of iron deficiency?
Negative iron balance - reduced iron stores, normal iron in erythrocytes without anaemia.
Iron deficient erythropoiesis - reduced iron stores, mildly reduced erythron iron, without anaemia
Iron deficiency anaemia - reduced iron stores and erythron iron with anaemia
What are some clinical features of iron deficiency anaemia?
Atrophic glossitis (smooth tongue without pappilae)
Angular cheilitis (redness and fissures at corners of the mouth)
Koilonychia (spoon nails)
Which factors are low in iron deficiency anaemia?
Hb
Hct
MCV (microcytic anaemia)
MCH (less haemoglobin per cell)
RCC (less red cells)
What kind of cells do we see in iron deficiency anaemia blood film?
Hypochromic microcytic cells
Pencil cells
Elliptocytes
What happens to reticulocyte count in iron deficiency anaemia?
It is reduced
What happens to platelet numbers in iron deficiency anaemia? Why?
It is increased causing mild thrombocytosis
Body responding to blood loss
What are lab measures of iron status?
Serum iron
Serum transferrin
Transferrin saturation
Serum ferritin
Is serum iron a reliable measure of iron stores?
No, it is highly variable
What does serum transferring measure?
The amount of iron transporter
What is transferrin saturation?
Amount of transferrin occupied by iron
What is serum ferritin?
Reflects body stores
What investigations should be done following a discovery of iron deficiency anaemia?
Malabsorption test for coeliac disease
Testing GI and uterine tract for blood loss
How are the GI and uterine tract tested for blood loss?
Gastroscopy
Colonoscopy
Capsule endoscopy
Pelvic U/S
What is done to manage iron deficiency?
Treat underlying cause (Blood loss or coeliac’s should be treated)
Iron replacement therapy (could be oral, intramuscular or intravenous if severe)
Blood transfusion (rarely required)
When is iron replacement therapy stopped?
Until Hb is normalised as well as ferritin stores
What are possible results of oral iron replacement therapies?
reticulocytes response begins in 7 days
Poor response may be seen in continued bleeding, malabsorption, poor compliance (patient forgets or refuses to take tablets) and incorrect diagnosis
What are possible complications of Intravenous iron replacement therapies?
Same side effects as oral iron.
Ongoing blood loss that exceed capacity of oral iron
What is the normal result of partially treated iron deficiency?
Dimorphic blood film showing some normal RBCs and some deficient RBCs
What is the most important consideration for iron deficiency anaemia?
That the underlying cause is treated because iron deficiency is a secondary diagnosis
