L28 Bleeding disorders (II) Flashcards
The difference of site of bleeding between vWFD/Platelet disorders VS Coagulopathy?
- vWFD& Platelet disorders
- mucocutaneous: skin, mucous membrane e.g. gum, epistaxis, vaginal, GI tract - Coagulopathy
- Deep in soft tissue, e.g. joint and muscles
What are petechiae? How to differentiate it from angioma and vasculitis?
The difference in presence of petechiae between vWFD/Platelet disorders VS Coagulopathy?
Petechiae
- pinpoint areas of hemorrhage in subcutaneous tissue
- not blanchable on pressure c.f. angioma
- not palpable c.f. vasculitis
- vWFD& Platelet disorders
- Present, RBC leaks through postcapillary venules - Coagulopathy
- no petechiae
What is ecchymosis?
The difference in presence of ecchymosis/purpura between vWFD/Platelet disorders VS Coagulopathy?
Ecchymosis: gradual onset, progressive bruises
- vWFD & Platelet disorders
- small and superficial - Coagulopathy
- Large, deep: lack of thrombin prevents secondary/ tertiary hemostasis
The difference in presence of hemarthrosis and muscle bleeding between vWFD/Platelet disorders VS Coagulopathy?
- vWFD & Platelet disorders
- Extremely rare - Coagulopathy
- common
The difference in presence of bleeding after cuts/ scratches between vWFD/Platelet disorders VS Coagulopathy?
- vWFD & Platelet disorders
- common/yes - Coagulopathy
- no
The difference in presence of bleeding after surgery/trauma between vWFD/Platelet disorders VS Coagulopathy?
- vWFD & Platelet disorders
- immediate, usually mild - Coagulopathy
- delayed (1-2 days), severe
(platelets can initially stop bleeding but the plug is not stabilized and will be washed away easily.
List what would you like to ask in history taking (HPI) in patients who presented with bleeding disorders.
- Site of bleeding: mucocutaneous/ hemarthrosis
- Nature of bleeding
- frequency
- duration
- amount
- type of insults associated - Childhood: congenital cause
- Gynaecological: menarche, menorrhagia, post-partum
What are the important PMH that you have to ask in Bleeding disorder Hx taking? (3)
- Liver disorders: coagulopathy
- Connective tissue/ rheumatologic disorders: vascular problem
- Malabsorption: acquired vascular problem
What are the possible significant family history examples that you would like to ask?
- Hemophilia - X-linked recessive
- Von-Willebrand disease (vWD)- autosomal dominant
- Others: Autosomal recessive
What signs would you expect to see in patients with bleeding disorders?
- Ecchymoses/petechiae/ hematoma: size, location, distribution
- Signs of anemia
- Signs of systemic diseases: chronic liver disease, lymphadenopathy, hepatosplenomegaly
- Others:
- skin laxity (Ehlers-Danlos syndrome [everything loose!!]),
- lips and oral mucosa telangiectasia (vascular problems)
What would you investigate in suspected platelet/vWD?
- CBC: platelet count
- vWF
- Platelet function test
What would you investigate in suspected coagulopathy?
- Clotting profile: PT, APTT
- Mixing test
- Factor/inhibitor essay
Prothrombin time is the measurement of the time for the ___________ system.
Describe the pathways
Extrinsic system (tissue damage) > tissue factor + Factor 7 > Factor 7a
> F9a + F7a changes F10 to F10a
F10a changes F2 to F2a (thrombin)
F2a (thrombin changes Fibrinogen to fibrin
List 4 reasons for prolonged PT.
- Vitamin K antagonist admistration (e.g. warfarin)
- Liver disease
- Vitamin K deficiency
- Factor 2,7,9,10 deficiencies/inhibitor
Activated partial thromboplastin time (APTT) is the measurement of the time for the __________ system.
Describe the pathways.
Intrinsic (surface contact)
- Factor 12 > Factor 12a added to Factor 11 >
- Factor 11a added to Factor 9 >
- Factor 9a + factor 8a added to Factor 10 >
- Factor 10a + Factor 5a added to Factor 2>
- Factor 2a (thrombin)
- Factor 2a + fibrinogen > fibrin
List 4 reasons for prolonged APTT.
- Vitamin K deficiency (2,7,9,10)
- Vitamin K antagonists
- Factor 2,5,10 deficiency/inhibitor
- Multiple factors deficiency e.g. liver failure, DIC
What is thrombin time?
List 4 reasons for prolonged thrombin time.
Thrombin time
= time for changing fibrinogen to fibrin by factor 2a (thrombin)
Prolonged when
- Hypofibronogenemia - congenital/DIC
- Dysfibrinogenaemia - inherited or liver disease
- Presence of heparin, paraproteins
- Raised concentration of Fibrin Degredation Product - as in DIC
In patients with abnormal clotting profile, it is either due to clotting factor deficiency OR presence of inhibitors: antibodies which inhibit the function of clotting factor.
How to distinguish these 2 causes? (2)
- Screening tests: 50:50/ 1:1 mixing of normal and patient’s plasma and then repeat the test
- Confirmation: Specific factor/ inhibitor assay
1:1 Mixing test:
Factor 8 0% > APTT 120s
+
Patient’s blood 100% > APTT 30s
= APTT 35s
What does it mean?
decreased clotting time (from 120s to 35s) = factor8 deficiency
Unchanged clotting time = inhibitors
Management options for bleeding if due to platelet problems?
(rather than coagulation/fibrinolysis)
(2)
- Blood products transfusion: platelet transfusion
- Drugs: Desmopressin DDAVP
(for stimulating the release of vWF from endothelium)
Management options for bleeding if due to coagulation problems? (rather than platelet/fibrinolysis)
(list 2/5)
Blood products transfusion
- Platelets
- Cryoprecipitate (prepared from plasma and contains fibrinogen, von Willebrand factor, factor VIII, factor XIII and fibronectin)
- Factor concentrates
Drugs
- Clotting factor concentrate
- Recombinant human factor 7a