#25 - bleeding disorders Flashcards
2 categories of bleeding disorders
1-platelet disorders
2-coagulation factor disorders
2 categories of bleeding disorders
1-platelet disorders
2-coagulation factor disorders
mucocutaneous bleeding, bruises/echchymoses, petechiae suggest which type of disorder?,
platelet defect
platelet defect usually leads to which type of bleeding?
bleeding, bruises/echchymoses, petechiae
hemarthrosis, hematuria, deep hematoma all suggest what type of bleeding disorder?
coagulation factor defect
bruising, mucocutaneous bleeding, and hemarthrosis (bleed into joint) suggest which type of disorder?
both types of bleeding = suggest von Willebrand disease
What is the normal level of platelets?
150,000 to 450,000
At what level of platelets will spontaneous (life threatening) bleeding occur?
prothrombin time (PT) tests which process of coagulation / factors?
initiation of coagulation .
factor 7
PTT tests which factors?
8 and 9
PT is prolonged by what?
- liver disease
- vit K deficiency
- warfarin
PTT is prolonged by what?
- hemophilia
- heparin
- coagulation inhibitors
mucocutaneous bleeding, bruises/echchymoses, petechiae suggest which type of disorder?,
platelet defect
platelet defect usually leads to which type of bleeding?
bleeding, bruises/echchymoses, petechiae
hemarthrosis, hematuria, deep hematoma all suggest what type of bleeding disorder?
coagulation factor defect
bruising, mucocutaneous bleeding, and hemarthrosis (bleed into joint) suggest which type of disorder?
both types of bleeding = suggest von Willebrand disease
Clinical Presentation of Thrombotic thrombocytopenic purpura
- thrombocytopenia
- renal dysfunction
- fever
- rash
- petechiae in oral mucosa
- 3+ schistocytes!!
At what level of platelets will spontaneous (life threatening) bleeding occur?
At what level of platelets will increased risk of bleeding occur?
prothrombin time (PT) tests which factor?
factor 7
PTT tests which factor?
8 and 9
PT is prolonged by what?
- liver disease
- vit K deficiency
- warfarin
PTT is prolonged by what?
- hemophilia (factor 8 and 9 deficiency),
- coagulation factor inhibitors
- heparin
T/F Acquired (qualitative) platelet defects are common
True (congenital defects are rare)
what is idiopathic/immune thrombocytopenic purpura?
severe thrombocytopenia, usually
treatment for ITP (idiopathic/immune thrombocytopenic purpura)
- children - self limited - not needed
- adults - it is chronic, treatment needed. corticosteroids.
Schistocytes on the peripheral blood smear indicate
microangiopathic hemolysis
Clinical Presentation of Thrombotic thrombocytopenic purpura
- thrombocytopenia
- renal dysfunction
- fever
- bleeding
- 3+ schistocytes!!
Treatment of TTP - Thrombotic thrombocytopenic purpura
hematologic emergency!!
urgent plasma exchange
What causes TTP? (Thrombotic thrombocytopenic purpura)
Many cases caused by deficiency of vWF - cleaving protease (ADAMTS13).
You end up with ultra-large multimers of vWF, which bind platelets too much, causing thrombosis and lowered platelet counts
labs in TTP (Thrombotic thrombocytopenic purpura)
- PT and APTT usually normal
- high LDH
What is the role of von WIllebrand factor?
- it facilitates platelet adhesion to injured endothelium
- it binds and carries factor 8 in plasma
(this is why it causes platelet and coag factor bleeding)
Treatment for hemophilia b
- factor 9 concentrate for everyone, all severities.
- antifibrinolytic agent for
complications of hemophilia treatment
- expensive
- pt’s develop antibodies to the factors they are given.
3 common causes of acquired platelet defects
- Drugs (NSAIDs, clopidogrel)
- uremia/ renal disease
- liver failure
characteristics of von willebrand disease - clinical presentation
- lifelong bleeding
- -prolonged PTT, which corrects with mixing.
- prolonged PFA-100
- decreased levels of vWF and Factor 8
Who gets hemophilia A and B?
young boys - they are X linked recessive disorders
presentation of hemophilia
young boy
-prolonged PTT which corrects to normal with 1:1 mixing.
What levels of factor 8/9 define severe, moderate and mild?
severe = 5%
only severe have spontaneous bleeds. Mild and moderate don’t have many symptoms
clinical findings for hemophilia
- hemarthrosis, hematuria, hematoma
- excessive surgical bleeding
- arthropathy
Treatment for mild hemophilia A
desmopressin (releases vWF from endothelium, increasing factor 8)
Treatment for moderate/severe hemophilia A
factor 8 concentrate (only for moderate / severe cases)
-antifibrinolytic agent for bleeding
Treatment for hemophilia b
- factor 9 concentrate for everyone, all severities.
- antifibrinolytic agent for
complications of hemophilia treatment
- expensive
- pt’s develop antibodies to the factors they are given.
characteristics of factor inhibitor diseases
don’t correct with mixing.
-result in low levels of a specific factor (eg if it’s a factor 8 inhibitor, it will show low factor 8 on labs)
- can be spontaneous, or as a result of hemophilia therapy.
- severe and difficult to control bleeding.
characteristics of von willebrand disease - clinical presentation
–prolonged PTT, which corrects with mixing.
-prolonged PFA-100
-
difference between type 1 and type 2 and type 3 von willebrand disease.
type 1 = quantitative deficiency of vWF
type 2 - qualitative deficiency of vWF
type 3 - complete absence of vWF
Treatment for mild von willebrand disease
desmopressin
Treatment for type 3 von willebrand disease (absence of vWF)
factor 8 / vWF concentrates
how do you differentiate TTP from DIC?
In TTP, PT and PTT are normal.
what is hemolytic uremic syndrome and what causes it?
HUS is a variant of TTP.
It is the leading cause of renal failure in children worldwide.
It is NOT caused by deficiency of ADAMTS13, it is caused by E coli shiga toxin.
What are the 4 most common causes of qualitative platelet defects?
- congenital
- drugs
- renal disease
- liver disease
