Haem Flashcards
What’s the pattern of inherited of haemophilia?
X Linked recessive
What are the 4T s in HIT pretest probability?
Thrombocytopenia (>50% decrease or platelet ~20)
Timing of thrombocytopenia (5-14 days)
Thrombosis (or skin necrosis)
OTher causes excluded
What test for the extrinsic pathway?
PT
What factors are in the intrinsic pathway?
TENET
(twelve-eleven-nine-eight-ten)
What is bound in HIT?
Platelet Factor 4
(Autoantibodies)
What receptor on platelets binds to vwf?
GP1B-V-IX (reversible adhesion to exposed extracellular matrix)
What does platelet adhesion to ECM trigger?
GPIIb-IIIa activation (irreversybinding to matrix ligand and platelet activation)
What does GPIIb-IIIa do?
Mediates platelet aggregation + binds fibrin to form fibrin clot
What does clopidogrel and ticagrelor work on?
P2Y receptor antagonists
PT-N, APTT-long, TT-N Fibr-N, Plt- N, diagnosis?
Factor VIII, IX XI, XII deficiency, vwf def
What is dilute Russel venom viper test used for?
Detecting presence of antiphospholipids, (prolonged test), esp b2gp.
Is also prolonged if DOAC present.
What hormonal state is the most risky for clots?
Post-partum
How does VITT doffer from HIT?
No heparin exposure
What is the bleeding pattern with platelet type bleeding disorders
Skin, mucosal membranes, vaginal, petichiae common, prolonged bleeding from skin cutes, bleeding immediately
What is the bleeding pattern with clotting factor disorders?
Deep soft tissue bleeds, muscles, joints, minimal bleeding from skin cuts as primary haemostasis intact, bleeding delayed 1-2 days and often severe (e.g post op day2)
What clotting factor deficiency has no clinical significance?
XII
What is inheritance of haemophilia?
X-Linked recessive, 1/3 if cases have no apparent family history
What is emicizumab?
MAB used in Haemophilia A to act as factor 8 and bond X to IX
What is type 1 VWF disease?
Partial quantitative deficiency. most common , 70-80%
What is VWD 2B?
Increased affinity of VWF for GP1B, selective deficiency of high molecular weight multimeters
What is VWD type 3?
Complete deficiency VWF
How to treat VWD?
Replace VWF, dvavp in acute bleeding if required (releases stores from wible plaby bodies)
What is the reversal agent for heparin?
Protamine
What does PFA100 test?
Primary haemostasis - used in assessment of VWD