Corrections 2 Flashcards
What does cryoprecipitate contain?
Factor VIII
Fibrinogen
vWf
Factor XIII
What is the major constituent of cryoprecipitate?
Factor VIII
What is CML blast transformation?
The final stage of CML
CML transforms until an acute leukaemia, usually AML.
Features of blast transformation in CML?
- fever
- fatigue
- SOB
- enlarged spleen
- bone pain
- abdo pain
- night sweats
- weight loss
- bleeding
- infections
What is the universal donor of FFP?
AB RhD negative
Mechanism of dabigatran?
Direct thrombin inhibitor
What investigation should be used to diagnose hereditary spherocytosis?
EMA binding test
1st line imaging in suspected multiple myeloma?
Whole body MRI - to assess for bony involvement
What is the treatment of choice in TTP?
Plasma exchange
Features of TTP?
- fever
- fluctuating neuro signs (microemboli)
- renal failure
Blood test results in TTP?
1) Microangiopathic haemolytic anaemia –> schistocytes
2) Thrombocytopenia
What are schistocytes on a peripheral blood smear a characteristic feature of?
Microangiopathic hemolytic anemia:
- DIC
- TTP
- HUS
- HELLP
- malfunctioning cardiac valves
Causes of TTP?
- post-infection e.g. GI, urinary
- pregnancy
- SLE
- HIV
Metabolic abnormalities in tumour lysis syndrome?
- high potassium
- high phosphate
- low calcium
What is the platelet threshold for transfusion for patients with severe bleeding, or bleeding at critical sites, such as the CNS?
<100
Platelet transfusion thresholds:
1) patients with clinically significant bleeding e.g. haematemesis, melaena, prolonged epistaxis
2) patients with severe bleeding or CNS bleeding
1) <30
2) <100
What platelet level should you aim for prior to surgery/invasive procedure?
> 50
How should TXA be given in cases of major haemorrhage?
IV bolus followed by slow infusion
What is the most common hereditary haemolytic anaemia in people of northern European descent? (e.g. Finland)
Hereditary spherocytosis
What is erythema infectiosum caused by?
Parvovirus (‘slapped cheek’)
Mx of post-thrombotic syndrome?
Graudated compression stockings
Features of post-thrombotic syndrome?
- painful, heavy calves
- pruritus
- swelling
- varicose veins
- venous ulceration
What is required to diagnose tumour lysis syndrome?
Laboratory tumour lysis syndrome plus one or more of the following:
1) increase in serum creatinine (1.5x upper limit of normal)
2) cardiac arrhythmia or sudden death
3) seizure
A peripherlal blood smear showing spherocytes can be found in what 2 conditions?
1) hereditary spherocytosis
2) autoimmune haemolytic anaemia
Pathophysiology of haemophilia?
Interferes with the intrinsic pathway of the coagulation cascade.
Factor VIII/IX deficiency –> reduced activation of factor X to Xa –> reduced generation of thrombin –> reduced conversion of fibrinogen (soluble) to insoluble fibrin (provides structural integrity of a clot).
Which clotting pathway is affected in haemophilia?
Intrinsic coagulation cascade
What clotting study result is one of the hallmarks of haemophilia?
Prolonged APTT (this represents a delay in the intrinsic coagulation pathway).
How can clotting studies differentiate between vitamin K deficiency or DIC and haemophillia?
Haemophilia:
- prolonged APTT (intrinsic)
- normal PT
Vitamin K deficiency:
- prolonged PT
- can have a prolonged APTT
What is the most sensitive screening test to detect early or mild vitamin K deficiency?
Prolonged PT
Mx of haemophilia?
Replacement of clotting factors: VIII in haemophilia A, IX in haemophilia B
What can be used in acute episodes of mild haemophilia A to promote the function of vWf?
Desmopressin
Inheritance of thalassaemia?
Autosomal recessive
Cause of beta-thalassaemia?
Mutation in globin (HBB) gene on chromosome 11
HbA vs HbA2 levels in beta-thalassaemia major?
HbA: absent
HbA2: raised (HbF is also raised)
What is required for a diagnosis of polycythaemia vera?
1) Mutation in JAK2
and
2) High haematocrit (>0.52 in men, >0.48 in women) OR raised red cell mass (>25% above predicted)
What is used to reduce risk of thrombosis in polycythaemia vera?
Aspirin
1st line mx of polycythaemia vera?
Venesection
What is the mainstay of imaging for staging HL?
PET/CT
This combines functional imaging from PET, which detects areas of increased metabolic activity, with anatomical imaging from CT, providing precise localisation of disease sites.
What is the initial investigation of choice in suspected polycythaemia vera?
JAK2 mutation screen - this is +ve in approx 95% of PV cases
Mechanism of:
a) rivaroxaban
b) apixaban
c) dabigatran
d) heparin
a) direct factor Xa inhibitor
b) direct factor Xa inhibitor
c) direct thrombin inhibitor
d) activates antithrombin III
What clotting factors does warfarin inhibit?
II, VII, IX and X
What is the most likely biochem findings in myeloma (without mets)?
- raised calcium
- normal phosphate
- normal ALP
Is extra-nodal disease more common in HL or non-HL?
Non-HL
What medication is often used in the mx of non-HL?
Rituximab
What should all patients be screened for prior to receiving treatment with rituximab?
Hep B (can cause reactivation)
Why does SLE commonly cause neutropenia?
Autoimmune destruction of neutrophils
What is the single most important factor in determining whether cryoprecipitate should be given?
A low fibrinogen level
What is cryoprecipitate mainly used in the mx of?
DIC –> indicated for the treatment of hypofibrinogenaemia
What blood product may be indicated in:
a) prolonged APTT
b) prolonged PT
c) low fibrinogen
a) FPP
b) FPP
c) cryoprecipitate
