Haematolgy Flashcards
Differentiate the causes of megaloblastic and non-megaloblastic macrocytic anaemia
Megaloblastic: B12/folate deficiency (pregnancy, old age, veganism)
Non-megaloblastic: liver disease/ alcoholism/ multiple myeloma
Recall the 2 key symptoms and the 3 key signs of any anaemia
Symptoms: lethargy, breathlessness
Signs: pallor, tachycardia, breathlessness
Recall 3 signs of pernicious anaemia that might be present in addition to the normal signs of anaemia
Glossitis
Angular stomatitis
Mild jaundice
What signs of B12 deficiency may be present alongside an anaemia?
Peripheral neuropathy
Optic atrophy
Dementia
How are LFTs commonly deranged in macrocytic anaemia and why?
High bilirubin
Ineffective erythropoiesis, haemolysis
What blood tests are done to detect B12 and folate levels?
Serum cobalamin
Red cell folate
As well as macrocytic erythrocytes, what can be seen on a blood film in megaloblastic anaemia?
Hypersegmented neutrophils
What test is done to diagnose pernicious anaemia?
Schilling test
Recall the management of pernicious anaemia
IM hydroxycobalamin for life
What is the most likely cause of a microcytic anaemia?
Iron deficiency
Recall 4 causes of iron deficiency
GI blood loss
Small bowel disease
Vegan
Pregnancy
What size are the red cells in anaemia of chronic disease?
Microcytic
In what sort of anaemia may the patient develop brittle nails and hair?
Iron deficiency anaemia
What might an FBC show in microcytic anaemia?
Low Hb
Low MCV
High reticulocytes
Recall the iron, TIBC and ferritin seen in iron deficiency anaemia
Iron: low
TIBC: high
Ferritin: low
Does thalassaemia produce a microcytic or a macrocytic anaemia?
Microcytic
Systematically recall some causes of normacytic anaemia
Decreased production: vit B2/6 deficiency, ACD, aplastic anaemia
Increased destruction: haemolysis
Increased blood volume: fluids, pregnancy
Define aplastic anaemia
A pancytopaenia due to fewer haemotopoietic precursors
What symptoms and signs of aplastic anaemia will not be present in any other aetiology of anaemia?
Symptoms of thrombocytopaenia Purpura Easy bruising Epistaxis Petechiae Also multiple infections due to leukocytopaenia
What are the 2 different types of disseminated intravascular coagulation?
Acute overt
Chronic non-overt
Differentiate the pathophysiology of acute overt and chronic non-overt disseminated intravascular coagulation
Acute overt: bleeding –> depletion of platelets and clotting factors
Chronic non-overt: thromboembolism –> generalised activation of coagulation system
What sort of infection is most likely to cause disseminated intravascular coagulation?
Gram negative sepsis
Describe the pathophysiology of DIC
Endothelial damage –> tissue factor release
Tissue factor activates thrombin
Thrombin depletes clotting factors and platelets
Thrombin activates fibrinolysis
Fibrinolysis releases fibrin, which occludes the microvasculature
Which patients are particularly at risk of disseminated intravascular coagulation?
Pretty much all severely unwell patients will get
Differentiate the signs that are present in acute and chronic disseminated intravascular coagulation
Acute: purpura, petechiae, ecchymoses, epistaxis
Chronic: signs of DVT/ arterial thromboses
Describe the FBC of someone with disseminated intravascular coagulation
Low Hb and platelets
What should be tested for alongside FBC in the blood in suspected disseminated intravascular coagulation
APTT (will be high)
FDP (will also be high)
Recall the pathophysiology of haemachromatosis
GENETIC increase in iron absorption, iron accumulates in tissues, organs damaged
Recall some late symptoms of haemachromatosis
T2DM Bronzed skin Hepatomegaly Cirrhosis Hypogonadism Cardiac arrhythmias/ cardiomyopathy
Recall the results of haematinic investigations in haemachromatosis
Ferritin: high
Transferrin: low
[Transferrin]: high
TIBC: low
Systematically recall possible causes of haemolytic anaemia
- Hereditary
a) membrane defects - elliptocytosis, hereditary spherocytosis
b) haemaglobinopathies: thalassaemia, sickle-cell disease
c) metabolic defects: G6PD deficiency, PKU deficiency - Acquired
Infection: sepsis, malaria
Trauma
Drugs
Autoimmune
Recall 2 symptoms of haemolytic anaemia that are not present in other types of anaemia
Jaundice (due to increased red cell breakdown)
Haematuria (due to haemolysis)
Is haemolytic anaemia macrocytic or microcytic?
Macrocytic
Recall 3 abnormalities found on urinalysis in haemolytic anaemia
- High urobilinogen
- Haemaglobinuria
- Haemosiderinuria
What specific test is done for auti-immune haemolytic anaemia?
Direct Coomb’s test
What are the 2 categories of haemolytic uraemic syndrome
D+ (with diarrhoea, usually children)
D- (no prodromal illness)
Define haemolytic uraemic syndrome
Triad of microangiopathic haemolytic anaemia, thrombocytopaenia and acute renal failure
Explain the pathophysiology of HUS and TTP
Endothelial damage –> platelets aggregate
1a. Platelet aggregation –> thrombi formation –> promotion of intravascular haemolysis
1b. Platelet aggregation –> loads of vWF released –> small vessel thrombosis
Small vessel thrombi most likely to affect afferent glomerular arterioles which is why HUS + TTP –> renal failure
What is the difference between thrombotic thrombocytopaenic purpura and haemolytic uraemic syndrome
TTP has extra clinical manifestation of fever and CNS signs
Which pathogen is the most common cause of HUS and where it is usually found?
E Coli 0157
Contaminated water
Recall the symptoms of HUS
General sickness/ malaise
GI symptoms: bloody diarrhoea, severe colic
Renal symptoms: oligouria, haematuria
Describe the FBC results for someone with HUS and TTP
Normacytic anaemia
High neutrophils
VERY LOW platelets
What would an ABG show in HUS?
Lactic acidosis
What would a blood film show in HUS?
High reticulocytes and schistocytes
Recall 3 symptoms of haemophilia
- Haemarthroses
- Haematuria
- Deep bleeding
Recall 2 investigations that should be done in suspected haemophilia
Clotting factor assay
APTT
What is immune thrombocytopaenic purpura?
Immune destruction of platelets
What is the antibody that is implicated in immune thrombocytopaenic purpura?
Anti-GpIIb/ anti-GPIIIa
Recall the general signs/ symptoms of ITP
Easy bruising, epistaxis, visible purpura, menorrhagia
What will the result of a clotting screen be in ITP?
Normal
Why is it important to do a blood film in suspected ITP?
Need to rule out pseudothrombocytopaenia
What is the most common malignancy of childhood?
Acute lymphoblastic leukaemia