Lecture 6: Bleeding Disorders Flashcards
What is primary hemostasis?
Activation of platelets and formation of initial platelet plug in wall of injured vessels
What screening tests are included for primary hemostasis? (3)
(1) Platelet count
(2) Platelet function assay (PFA)
(3) Platelet aggregation studies- PT, PTT, thrombin time
What is secondary hemostasis?
Activation of plasma coagulation factors and formation of a fibrin clot
What screening tests are included in secondary hemostasis? (3)
(1) Prothrombin time (PT)
(2) Partial Thromboplastin Time (PTT)
(3) Thrombin Time (TT)
What is the difference between primary hemostasis and secondary hemostasis?
Primary hemostasis is a platelet-type disorder while secondary hemostasis is a clotting cascade problem
What will you see on physical exam for primary hemostasis? (5)
(1) Superficial bleeding
(2) Mucocutaneous bleeding
(3) Petechiae
(4) Immediate bleeding after trauma
(5) Bleeding controlled by direct pressure
Which hemostasis is not controlled by direct pressure?
Secondary hemostasis
What will you see on physical exam for secondary hemostasis? (4)
(1) Deep muscle bleeding: Hemarthrosis
(2) NOT petechiae
(3) Delayed bleeding after trauma
(4) Not controlled by direct pressure
When do you want to pursue further workup? (in relation to abnormal labs and bleeding history)
When you have abnormal labs AND a bleeding history!
When do you suspect a PLT disorder? (PLT=platelet) (4)
(1) Bleeding pattern consistent with quantitative or qualitative PLT dysfunction
- superficial bleeding
- mucocutaneous bleeding
- petechiae
- immediate bleeding after trauma/surgery
(2) Thrombocytopenia
(3) Abnormal # or size PLT on blood smear
(4) Abnormal PLT aggregation studies or PFA
What are 2 inherited PLT disorders? What are 2 major differences in diagnosing these disorders?
(1) Bernard-Soulier
- Thrombocytopenia and giant PLT size
- PLT aggregation studies NORMAL except to ristocetin
(2) Glanzmann thrombasthenia
- Normal PLT count and size
- PLT aggregation studies ABNORMAL except to ristocetin
What is the treatment of Inherited PLT disorders if bleeding?
PLT transfusion if bleeding
What is defective on PLT with Bernard-Soulier disorder? Glanzmann thrombasthenia?
Defective GpIb/IX complex (receptor to vWF); Defective GpIIB/IIIa (receptor for fibrinogen)
T/F Both Bernard-Soulier and Glanzmann thrombasthenia are autosomal dominant inheritance.
FALSE; autosomal RECESSIVE inheritance
What are 2 acquired PLT disorders?
(1) Drug induced qualitative platelet disorder
2) Immune Thrombocytopenic Purpura (ITP
What is seen with ITP (in regards to blood)?
- Isolated thrombocytopenia
- Blood count is normal
What is the pathophysiology of ITP? (2)
(1) Immune mediated destruction
(2) Decreased PLT production
When is spontaneous remission of ITP seen?
In children; NOT in adults (uncommon)
What is the point of differentiation between patients with ITP that have increased mortality rate?
The “Safe” vs. “Normal” PLT count; though you may have less PLT count, you will have NO excess mortality in patients with mild to moderate disease as they have a “safe” number of platelets
How do you diagnose ITP?
Diagnosis of exclusion
- Isolated thrombocytopenia
- History, PE, CBC, and PBS do not suggest other etiologies
When would you consider doing a bone marrow biopsy? (in regards to diagnosing ITP)
To rule out cancer in patients >60 y/o
What is most common treatment for ITP?
DO NOTHING!
What will happen to PTT, PT, TT in secondary hemostasis?
They will be prolonged
What are 2 types of hemophilia? What are their deficiencies?
(1) Hemophilia A (classic hemophilia)- defect in Factor VIII
(2) Hemophilia B (Christmas disease)- defect in Factor IX
Why does hemophilia effect primarily males?
Because it is an x-linked recessive disorder
- Genes encoding for factors VIII and IX are located on X-chromosome
T/F Hemophilia can present as an acquired disorder.
True. Rarely, it can be antibody mediated as well
Which type of hemophilia is more common? Why?
Hemophilia A (80-85%); because the FVIII gene is larger and thus more susceptible to mutations
What is the variability (in levels) in severity of bleeding for hemophilia? (3)
(1) Factor VIII levels 5-25%- MILD; very few problems unless surgery or major trauma
(2) 1-5%- MODERATE; bleeding after minor trauma
(3) <1%- SEVERE; presents in childhood
What are the various sites of bleeding in hemophilia? (4) What is absent?
(1) Intra-articular bleeding
(2) Intra-muscular hemorrhage
(3) Hematuria
(4) Life threatening hemorrhage
- GI bleeding
- Retroperitoneal
- Intracranial
- Retropharyngeal
~Absent: Petechiae and superficial ecchymoses~
What are the most common sites of bleeding with hemophilia?
Hemarthrosis- joints
What are the confirmatory labs for hemophilia when you have prolonged PTT?
(1) 1:1 PTT mixing study
(2) Coagulation factor assay
What is the 1:1 PTT mixing study?
- Patient’s plasma and normal pooled plasma
- the clotting time corrects to 50%
- it is enough to correct the PTT
What is hemophilia management? What do you want to avoid?
Factor replacement; NSAIDS
What is Von Willebrand Disease?
Inherited deficiency/defect in Von Willebrand’s factor
What does VWF do? (2)
(1) Platelet adhesion to subendothelial collagen and platelet-platelet binding= primary hemostasis (platelet plug)
(2) Carrier molecule for Factor VIII in plasma= secondary hemostasis (fibrin clot)
What is the most common inherited bleeding disorder?
Von Willebrand Disease
T/F Von Willebrand disease is an autosomal dominant inheritance.
TRUE
What is one different to distinguish between Von WIllebrand Disease and Hemolysis.
VWD is seen in males and females equally. Hemolysis= males
Which type of VWD is most common?
Mild (type 1) 70-75%
What is the difference between types 1 and 3 VWD? between 1,3 and 2?
type 1=partial quantitative deficiency in VWF
type 3=complete deficiency of VWF
type 2= QUALITATIVE
What are the symptoms of type 1 VWD?
PLT-like bleeding
- Epistaxis, gingival bleeding, easy brusing
(excessive menstrual or post-partum bleeding)
(bleeding after surgery or dental extraction)
What are the symptoms of type 3 VWD?
- GI bleeding, hemarthrosis, deep hematomas (female patient with “hemophilia”)
- undetectable multimers
VWD treatment
DDAVP
