Haematology Flashcards
what are the features of anaemia?
fatigue, fainting, breathless, angina, intermittant claudication, pale skin and mucous membraines, tachycardic, cardiac failure, systolic flow murmer
Name some causes of MCV low anaemia
iron deficiency, chronic disease, thallasaemia
name some causes of MCV normal anaemia
acute blood loss, chronic disease, iron and folate deficiency
name some causes of MCV high anaemia
B12/folate deficiency, alcohol, liver disease, hypothyroid
causes of iron deficiency
blood loss, increased demand (growth/pregnancy), reduced absorption (coeliac/bowel dis), reduced intake
what Ix do you do for anaemia?
blood count and film serum ferritin serum iron and TIBC serum transferrin BM exam
how do you manage iron deficiency anaemia?
ferrous sulphate
causes of B12 deficiency?
vegans, pernicious anaemia, gastrectomy, crohns disease, coeliac
how is B12 absorbed?
binds to intrinsic factor which is released by gastric parietal cells and then absorbed in the ileum and stored in the liver
what is pernicious anaemia?
autoimmune condition with atrophic gastritis with loss of parietal cells
where do we find folate in our diet?
green vegetables, liver and kidney
name some causes of folate deficiency
damage to upper intestine (where it is absorbed) - crohns/coeliac
age, poverty, alcohol, pregnancy, lactation, methotrexate
what is aplastic anaemia?
BM failure, pancytopenia (deficiency of all cell elements of the blood and BM aplasia)
What is haemolytic anaemia?
destruction of RBCs with reduced circulating lifespan of 120 days. compensatory increase in BM activity with release of immature red cells
causes of haemolytic anaemia?
hereditary spherocytosis/elliptocytosis, thalassaemia, sickle cell, G6PD deficiency, autoantibodies, malaria
how can you manage haemolytic anaemia?
splenectomy
what are A and B thallasaemia?
A = reduced A chain synthesis B = reduced B chain synthesis
Disorder in the gene for the chain = reduced rate of production of one or more globin chains
name some features of thallasaemia?
MINOR - genetic carrier state
INTERMEDIA - moderate anaemia, splenomegaly, bone deformities, leg ulcers, gallstones
MAJOR - severe anaemia, failure to thrive, recurrent infections, enlarged maxilla, hepatosplenomegaly
How do you manage thalassaemia? what needs to be given in addition to this Mx?
blood transfusions
give iron chelating agents too (desferrioxamine)
what is sickle cell?
autosomal recessive condition. HbS is a different shape when deoxygenated –> becomes insoluble and polymerises which increases rigidity of cells/sickle appearance/premature destruction and obstruction
what precipitates a sickle crisis?
hypoxia, dehydration, infection, cold
Features of sickle cell?
child is normal until until 6 months old (due to HbF)
OCCLUSION - acute hand and feet pain, avascular necrosis of the BM, bone pain in the long bones
ANAEMIA - enlarged spleen, BM aplasia, increased haemolysis with drugs/infection
LONG TERM - deformed long bones, splenic atrophy, retinal ischaemia, cerebral infarction
how do you Mx sickle cell?
avoid precipitating factors, folic acid supplements
How do you Mx a sickle cell crisis?
paracetamol/NSAIDS
complications of sickle cell?
pain, swollen and painful joints, acute sickle chest, CNS deficit, pigment gallstones
what is autoimmune haemolytic anaemia and how do we diagnose it?
immune destruction of RBCs - we diagnose it with the COOMB’s TEST - tests for antibodies/complement on the surface of RBCs
how do we manage autoimmune haemolytic anaemia?
prednisolone, splenectomy
what causes polycythaemia?
increased EPO production produced by kidneys when they have signs of hypoxia
what is the difference between primary and secondary polycythaemia?
primary - mutation on polycythaemia gene (JAK2)
secondary - due to smoking/hypoxia
how do you investigate polycythaemia and what do the results show?
blood count (raised RBCs/raised PCV/Raised Hb)
what are the symptoms of polycythaemia?
headache, dizzy, tinnitus, visual changes, angina, intermittant claudication, DVT
how do you manage polycythaemia?
stop smoking/hypoxia (give O2)
venesection, low dose aspirin
what is thrombocytopenia?
low levels of platelets
what are some causes of impaired production of platelets (BM)
BM failure, megaloblastic anaemia, leukaemia, myelofibrosis, HIV infection
name some causes of excessive platelet destruction?
autoimmune - ITP
SLE
post transfusion
DIC
what is the main cause of ITP in children?
post viral
what do you find in the bloods?
platelet autoantibodies
management of ITP?
corticosteroids, IVIG, splenectomy
features of ITP?
routine bloods
petichae, purpura
bleeding (e.g. epistaxis)
catastrophic bleeding (e.g. intracranial) is not a common presentation
what is TTP?
widespread adhesion and aggregation of platelets - microvascular thrombosis and profound thrombocytopenia
causes of TTP?
pregnancy, SLE, infection, cancer
features of TTP?
purpura, fever, fluctuating cerebral dysfunction, haemolytic anaemia
management of TTP?
plasma exchange
what is Haemophilia A?
deficiency in factor 8, X linked recessive disease
features of haemophilia A?
depends on how low the plasma factor 8 levels are
SEVERE - spontaneous muscle/joint bleeds (arthropathy)
MOD - severe bleeding following injury
MILD - bleeding with trauma/surgery
Ix for haemophilia A and the results?
prolonged APTT, reduced factor 8 plasma levels
Mx of Haemophilia A?
IV factor 8 recombinant as prophylaxis pre surgery
hep A/B vaccinations
avoid contact sport
how are the haemophilias inherited?
x linked recessive
what is haemophilia B?
deficiency in factor 9
what is von Willebrand disease?
vWF deficiency leading to defective platelet function and factor 8 deficiency
features of vonWB disease?
mucosal bleeding - GI/nose bleeds
prolonged bleeding after dental work
what is shown on investigation of vWB disease?
prolonged bleeding time - due to defective platelet adhesion
Mx for vWB disease?
factor 8 concentrate
which clotting factors is vitamin K required for production of?
2, 7, 9, 10
what is DIC?
widespread fibrin generation within blood vessels caused by coagulation pathway initiation.
- consumption of platelets and coagulation factors
- secondary activation of fibrinoysis
name some causes of DIC?
sepsis, major trauma, tissue destruction, malignancy
Features of DIC?
complete haemostatic failure, thrombotic events
