Bleeding Disorders Flashcards Preview

Module 103: Theme 2 > Bleeding Disorders > Flashcards

Flashcards in Bleeding Disorders Deck (27):
1

Causes of bleeding

Vascular disorders, platelet disorders (thrombocytopenia, defective function), defective coagulation (inherited, acquired)

2

Pattern of bleeding

Depends on aetiology, Pattern of bleeding with a vascular and platelet cause bleeding into mucous membranes and skin)
Coagulation disorders: bleeding into joints and soft tissues

3

Vascular bleeding

Problems with vessel wall
Inherited: Hereditary haemorrhagic telangiectasia, Ehlers-Danlos syndrome
Acquired from: scurvy, steroids, senile

4

Thrombocytopenia

Low platelet count
under 150-400*10^9/l
Symptoms: Epistaxis, GI bleeds, menorrhagia, bruising - start when platelets less than 10
Acquired from: drug related, immune thrombocytopenia, disseminated intravascular coagulation

5

ITP

immune thrombocytopenia
Treat with steroids or IV immunoglobulins or occasionally splenectomy

6

Disorders of platelet function

Platelet count - normal to low
Acquired from drugs like aspirin or NSAIDs
Inherited: rare diagnoses

7

Coagulation disorders

Due to a defect in coagulation cascade
Usually acquired, inherited is rare

8

Haemophilia

A: deficiency in factor 8
B: deficiency in factor 9v (Christmas disease)
X linked - affects males only

9

Clinical features of haemophilia

Spontaneous bleeding into joints and muscles
Unexpected post-op bleeding
Chronic debilitating joint disease - recurrent bleeds in joints - results in arthritis
Usually is a family history

10

Inheritance of haemophilia

Carrier mums have haemophiliac sons
haemophiliac dads pass gene to daughters

11

Coagulation tests

APTT: Activated partial thromboplastin time - assesses the intrinsic pathway (factors 8, 9, 11, 12)
PT: Prothrombin time (tests factor 2, 5, 7, 10)
TT: Thrombin time
Fibrinogen level
Factor level assay
Bleeding time

12

Diagnosis of haemophilia

Prolonged APTT
Normal PT
Low factor 8 or 9 levels

13

Treatments of haemophilia

Historic: Fractionated human plasma
Current: Infusions of factor 8 or 9, prophylactic treatment

14

Von villebrand disease

Autosomal dominant disease with deficiency of vWF and factor 8 in plasma
vWF: large multimeric protein that carries factor 8 in the blood
vWF also binds platelets to endothelial collagen
Symptoms: mucocutaneous bleeds, nosebleeds, menorrhagia

15

Test for vWD

Prolonged APTT
Normal PT
Low vWF level
Prolonged bleeding time
Defective platelet function

16

Treatment for vWD

desmopressin, antifibrinolytics and plasma products

17

Liver disease

Can cause haemophilia
Defects synthesis of clotting proteins
Impaired platelet function and fibrinolysis

18

Disseminated intravascular coagulation (DIC)

Release of pro-coagulation material into circulation
Causes both bleeding and thrombosis to occur
Causes of this: cancer, severe infection, obstetric disasters

19

Meningococcal disseminated intravascular coagulation

Prolonged APTT, PT, TT, low fibrinogen, low platelets, raised D-dimers or raised fibrinogen degradation products (FDP)

20

Latrogenic

Overdose of anticoagulant drugs

21

Heparin

Treats MIs, PEs, DVTs

22

Warfarin

Used to treat PEs, DVTs, atrial fibrillation, prosthetic valves

23

DOACS

Direct novel oral anti-coagulation
Direct thrombin inhibitors: dabigatran, argatroban
Factor 10a inhibitors: rivaroxiban, apixaban

24

Vitamin K deficiency

Required for gamma-carboxylation of factors 2, 7, 9, 10
Inhibited by warfarin
Deficiency of vit k due to malabsorption of Vit k, bilary obstruction (jaundice), haemorrhagic disease of new-borns

25

Monitored by PT

Extrinsic - factors 2, 5,7, 10

26

Monitored by APTT

Intrinsic

27

Extrinsic and Intrinsic

Both pathways result in thrombin burst that produces a blood clot and haemostasis