HAEM - Clotting and Bleeding Disorders Flashcards
What is Haemophilia A
Factor VIII deficiency
Inheritance Haemophilias
X linked recessive
+ high rates new mutations)
What is Haemophilia B
Factor IX deficiency
Which haemophilia is more common
A
Clinical features of haemophilias (3)
Major bleeds from minor trauma
Rec haemarthroses –> arthropathies
Compartment syndrome/nn palsies
Ix Haemophilias (2)
Raised APTT
+ Low VIII/IX on assays
Mx Haemopilias - general (2)
Avoid NSAIDs
Avoid IM injections
Mx minor bleed - haemophilias (2)
Compression + elevation
Desmopressin
Mx major bleed - haemophilias
Recombinant factor 8/9 to raise factors to 50% of normal
Mx life threatening bleed - haemophilia
Recombinant factor 8/9 to raise factors to 100% of normal
What is von willebrands disease
Abscence of vWF –> platelet type disorder
PS vWD
bleeding post op
Menorrhagia
Epistaxis
Difference between AD and AR vWD
AR - complete loss vWF (20%)
AD = less severe depletion (80%)
Ix vWD (2)
APTT increase
INR/platelets within normal limit
Mx vWD
Expert Mx
Transenamic acid for minor bleed
Desmopressin/recom factor 8 if more severe)
Site of bleed + clue it gives for condition - mm/joint
Coagulation issue
Site of bleed + clue it gives for condition - purpura/epistaxis/menorrhagia/GI haemorrhage
Platelet issue/vWd
Site of bleed + clue it gives for condition - rec bleeds @ 1 site
Local endothelial abnormality
What does bleeding immediately after surgery tell you
= Platelet issue
What does bleeding several hours after surgery tell you
= coagulation issue
Clopidogrel mode of action
Irreversible modification of platelet receptor
Dipyrimadole
PDE inhibitor (affects aggregation)
Mode of action Heparin
Activates AT3 –> inactivation of thrombin + X
Desmopression mode of action
Stimulates exocytosis of vWF
Hence is useful in vWD/Haemophilia A
How long does Warfarin take to have an effect
up to 5 days
C/I Warfarin (4)
Peptic ulcer disease
Bleeding disorders
Severe HTN
Pregnancy
Target INR - Warfarin for DVT/PE
2-3
Target INR - Warfarin for AF
2-3
Target INR - Warfarin for rec DVT/PE
3-4
Target INR - Warfarin for prosthetic heart valves
3-4
NOACs - Xa inhibtors (3)
The Xabans
Apixaban
Rivaroxaban
Edoxaban
How are Xaban’s reversed
Andexanet alfa
Mode of action dabigatran
Thrombin inhibitor
Reversal of dabigatran by:
Idarucizumab
Which NOACs are approved for the 2’’ prevention in pt w/ AF
Dabigatran
Apixaban
Rivaroxaban
+ves of NOACs (4)
Rapid onset coag
> Predictable pharmacokinetics
Less interactions w/ foods/Dx
Dont need reg coag monitoring
-ve NOACs
Partially cleared by kidney
Hence need does reduction in CKD
Overcoag w/ Warfarin Mx- INR 4.5-6:
Reduce dose or omit
Restart when INR <5
Overcoag w/ Warfarin Mx - INR 6-8
Stop
Restart when INR <5
Overcoag w/ Warfarin Mx - INR >8 + minor/no bleed
Stop Warfarin
+ 0.5-2mg vit K PO
Overcoag w/ Warfarin Mx - INR >8 + major bleed
Stop warfarin
+ 5-10mg Vit K IV + octaplex or FFP
Why is Vit K not sufficient Mx for Warfarin OD in a major bleed
Can take hours to work
Mode of action LMWH
Inactivates factor Xa
route LMWH
LC
UFH - route
IV SC
When to use UFH over LMWH
When high risk of bleed
or in severe CKD when LMWH = C/I
Mode of action UFH
Potentiates anti thrombin III
Monitoring aim UFH
APTT at 6hrs
1.5-2.5
SE of heparins (4)
BLEED
Heparin induced thrombocytopenia (HIT)
OP - l term
Hyperkalaemia
C/I heparins (4)
Bleeding disorders
Platelets <60 x 10 9
Prev HIT
Peptic ulcer
Mx overcoagulation by heparins (2)
Stop infusion
Give protamine sulphate
2 drugs used in thrombolysis
Streptokinase
Alteplase
What is streptokinase
Purified fraction of filtrate obtained from haemolytic streptococci
What does streptokinase do
Activates plasminogen –> plasmin
Why is streptokinase not good for repeated use?
= antigenic
Mechanism of action alteplase
TPA increases plasminogen activation + fibrinolysis
C/I of thrombolysis (7)
Active bleed Severe HTN (>200/120) Recent head trauma Recent surgery Pregnancy/recent delivery 10days Severe liver disease/oesophageal varices Prolonged/traumatic CRP
What is thrombophilia
Inherited/acquired coagulopathy predisposing to thrombosis, usually vv
E.g.s of inherited thrombophilias (3)
APC resistance/Factor V Leiden
Antithrombin III deficiency
Prothrombin gene mutation
E..g of acquired thrombophilia
APLS
Indications for screening for a thrombophilia (6)
aa thrombosis <50 vv thrombosis <40 w/ no RF Familial VTE Rec unexplained VTE Unusual site thrombosis (mesenteric/portal) Rec foetal loss
Ix suspected thrombophilia’s (5)
FBC + clotting Fibrinogen [ ] +/- APC resistance test Lupus anticoag/anti-cardio-lipin ab Antithrombin + Protein C/S assays PCR
If APC resistance test is +ve, what is the next Ix
Factor V Leiden mutation PCR
What is DIC
Systemic activation of coagulation pathways –> extensive IV anticoagulation + fibrin clot development
What happens in DIC
Thrombotic occlusion of aa microvasculature
Depletion of clotting factors + consumption platelets –> haemorrhage
+ progressing to organ failure
Causes of DIC (7)
Infection --> sepsis Trauma Malig (leukaemia, solid tumours) Obstetric complication Sever LF Tissue destruction Toxic/immunogenic stimuli
CF DIC (3)
Bruising
XS bleeding from sites
RF
Ix DIC (4)
Low platelets + fibrinogen
Raised PT, APTT, bleeding time
Raised D dimer
Broken RBC/schistocytes on film
Tx DIC (3)
Tx cause
agressive resus, replace platelets, FPP, fibrinogen (cryopreicpitate)
Protein C
Most common blood group UK
O (47%)
Blood group O antigens + ab
Antigens - none
Ab - Anti-A + Anti-B
Blood group A - antigens and ab
Antigens - A
Ab - Anti-B
Blood group B - antigens and ab
Antigens - B
Ab - Anti-A
Blood group AB - antigens and ab
Antigens - A + B
Ab - none
What does group and save involve
Taking a sample from pt and determining what ABO group the pt blood is + screening for ab that may cause haemolysis reaction in transfused blood
how long does it take to do a cross match
40 mins
How long does it take to do a G+S
40 mins
In an emergency situation, how quickly can ABO matching be done (without antibody testing)
12 mins
What are packed red cells
All plasma is removed and replaced by additive –> in acute blood loss
What is FFP used for
Replacing coagulation factors in acquired deficiencies
What is cryoprecipitate useful for
DIC
How often should a transfusion reaction be monitored?
Ev 30 mins
Sx of acute haemolytic reaction during transfusion (5)
Agitation Raised T Low BP ABdo/Chx pain Signs DIC
Mx acute haemolytic reaction (4)
STOP transfusion
A-E
Keep IV line
0.9% saline
Mx of rash/urticaria during transfusion
Slow/stop transfusion + chloramphenamine
Mx of anaphylaxis during transfusion
STOP transfusion
Tx as per anaphylaxis guidelines
Mx of bacterial contamination of blood product for transfusion
Sepsis 6 protocol
Send blood unit to lab
What is TRALI
Transfusion related acute lung injury
ARDS b/c ab in donor plasma
PS TRALI (2)
Dyspnoea
CXR white out
Sx non-haemolytic ferbrile transfusion reaction
Shivering
Fever ½-1h after starting
Mx non-haemolytic febrile transfusion reaction (3)
Slow transfusion
Give antipyretic
Monitor
Mx fl overload during transfusion
Stop/slow
Give O2 + diuretic
Consider exchange transfusion
