Anaemia Flashcards
What is pancytopaenia?
not enough of red cells, white cells and platelets
What is leukopaenia?
not enough white cells
What is neutropaenia?
not enough neutrophils
What is lymphopaenia?
not enough lymphocytes
What is anaemia?
not enough red cells
What is thrombocytopaenia?
not enough platelets
What is polycythaemia?
too many red cells
What is leukocytosis?
too many white cells
What is thrombocytosis?
too many platelets
What is dyserythropoeisis?
red cells dont work properly
What is anaemia defined as?
a Hb level lower than normal for age and gender
What is the equation for tissue oxygen delivery?
= CO x Hb x % saturation x 1.34
Why is the equation for tissue oxygen delivery so important?
because it determines when to use blood, inotropes and oxygen
What is a mechanism for monitoring anaemic patients?
measure their HR because it is a linear equation so as Hb decreses HR will increase
What is the impact of anaemia?
reduced oxygen to tissues unless can compensate with increased CO
What are the clinical signs of anaemia?
- Pale
- Lethargic
- Failure to thrive
- Hypoxic (disorientated, confused)
- Ischaemia
- tachycardia
What are the three causes of anaemia?
failure of production, increased destruction/loss, inappropriate production
What can be determined about red blood cells from a blood film?
the size (normocytic, microcytic, macrocytic), the shape and the colour (normochromic, hypochromic, polychromic)
What is the cause of polychromasia?
the cell has too much RNA in it which means it is immature
What are the signs of increased destruction?
more reticulocytes, polychromasia, jaundice, haptoglobins
Why is it important to detect if the anaemia is caused by increased destruction or blood loss?
because Hb may fall rapidly because of it
What is the most common cause of anaemia caused by blood loss in older people?
colon cancer
What are the two possible causes of haemolysis?
the problem is internal cell or external to the cell
What are the three possible internal causes of haemolysis?
problem with the membrane, problem with the enzyme, problem with the Hb
What is the most common cause of problems with the membrane in red blood cells?
hereditary spherocytosis
What is the most common cause of problems with the enzymes?
G6PD deficiency
What are the most common causes of problems with the haemoglobin?
sickle cell or thalassemia
What are the 3 possible causes of haemolysis that is caused by an external cause?
immune mediated, mechanical or infection
What are the mechanical causes of haemolysis?
sepsis, hardware (e.g. valve), haemolytic uremic syndrome, haemangioma
What are the infectious causes of haemolysis?
malaria
What are the three causes of failure of production of red blood cells?
haematinics, marrow failure or supression, marrow invasion
Lack of which haematinics causes a macrocytic anaemia?
B12 and folate
Lack of which haematinic causes a microcytic anaemia?
iron
What is the differential diagnosis for microcytic anaemia?
iron deficiency or thalassemia
What causes bone marrow invasion?
- Leukaemia
- Solid tumour
- Fibrosis
- Metabolic/storage
- infection
What is the treatment for anaemia?
cause specific or if unknown cause transfusion will always work
On which chromosome are the ABO genes?
chromosome 9
On which chromosome is the H gene?
chromosome 19
If your blood group is A what antigens are present on your red blood cells?
A and H
If your blood group is B what antigens are present on your red blood cells?
B and H
If your blood group is AB what antigens are present on your red blood cells?
A and B
If your blood group is O what antigens are present on your red blood cells?
H
What do the ABO genes do?
codes for transferase enzymes which adds sugars to the H precursor
If your blood group is A what antibodies do you have?
B
If your blood group is B what antibodies do you have?
A
If your blood group is AB what antibodies do you have?
none
If you blood group is O what antibodies do you have?
A and B
What are the antigens of the Rhesus blood group system?
C, c, D, E and e
What is rhesus positive?
positive for the D rhesus antigen
What is rhesus negative?
negative for the D rhesus antigen
On which chromosome are the rhesus antigens located?
chromosome 1
Who has rhesus antibodies?
rhesus negative individuals who have been exposed to rhesus positive blood either through a tranfusion or pregnancy
What blood group is the universal donor for red blood cells?
O
What blood group is the universal donor for plasma?
AB
What happens if you transfuses a rhesus negative patient with rhesus positive blood?
there will be a mild immune reaction 7-10 days later which is not fatal but if the patient is ever exposed to rhesus positive blood again there will be a fatal immune reaction
What is haemolytic disease of the newborn and how is it prevented?
haemolytic disease of the newborn is where a rhesus negative mum has a rhesus positive fetus and furing the pregnancy or during birth the mum is exposed to the blood and amounts an immune response against it - during the next pregnancy the antibodies will cross from mum to the baby and attack the fetus’ red blood cells - it is prevented by giving the mum anti D antibodies during pregnancy so that if there is any fetal blood in her circulation the antibodies will destroy them and this prevents the mum ammounting an immune response against them
