Bleeding Disorders Flashcards
1
Q
Defect of Primary Hemostasis
A
- defect of platelets, vessels
- petechiae
- infection associated, drug reaction, scurvy, Ehler’sDanlos
2
Q
Defect of Secondary Hemostasis
A
- defect of coagulation cascade and regulation
- hematoma/hemarthrosis
3
Q
Common office presentations of thrombosytopenia
A
- asymptomatic, isolated –> ITP, gestational, liver disease, myelodysplastic syndrome, HIV
- symptomatic, severe –> drug-induced, immune
4
Q
Common hospital presentations of thrombocytopenia
A
- part of a multi-system illness
5
Q
Immune Thrombocytopenic Purpura (ITP)
A
- common autoimmune disorder
- autoantibodies to platelet GP IIb/IIIa
6
Q
Acute ITP
A
- self-limiting
- almost exclusively in children
- preceded by viral illness or vaccine
- probably d/t exposure of cryptantigens or pseudoantigens
- sudden onset, mucocutaneous bleeding
- NO LAD or splenomegaly
- Tx: observe if no or mild bleeding, IVIg, RhIg, steroids
- histo: reduced platelets, increased megakaryocytes
7
Q
Chronic ITP
A
- adults 20-40, F>M
- reduced platelet lifespan d/t Ab mediated destruction
- diagnosis of exclusion
- usually no precipitating causes
- splenomegaly may be present
- Tx: reduce risk of bleeding
- need to exclude myelodysplastic disorders
8
Q
Heparin-induced thrombocytopenia
A
- highest risk with prolonged use for postop
- type 1: presents in first 2 days, non-immune, direct effect of heparin on platelet activation
- type 2: immune-mediated, 4-10 days after, immune complexes bind heparin-platelet factor 4 complexes and promote a prothrombotic state
- usually presents with thromboembolism (DVT, PE)
- Dx: HIT Abs studies
- prog: severe, limb loss, stroke, or death
9
Q
HIV associated thrombocytopenia
A
- more common with progressive immunosuppression but can occur at any point in infection
- ineffective platelet production and/or increased peripheral destruction
- splenomegaly may be present
10
Q
Thrombotic thrombocytopenic purpura (TTP)
A
- thrombosis in small vessels and subsequent low platelet count
- age 40-52
- sx: hemolytic anemia, thrombocytopenic purpura, neurologic abnormalities, fever, renal disease
- deficiency of ADAMTS13, E. coli infection, meds or pregnancy can be associated
- histo: RBC fragmentation, megakaryocytic hyperplasia
- normal PT, aPTT, D-dimer
- Tx: medical emergency! plasma exchange
- platelet transfusion NOT indicated
11
Q
Hemolytic-uremic syndrome (HUS)
A
- progressive renal failure associated with microangiopathic hemolytic anemia and thrombocytopenia
- most common cause of acute renal injury in kids
- associated with shiga-like toxin from E. coli infection
- sx: bloody diarrhea, seizures, renal failure
- labs: renal failure, hemolytic anemia, stool culture
- Tx: supportive
12
Q
Atypical HUS
A
- similar to HUS but no association to shiga-like toxin
- more frequent in adults, doesn’t usually present with diarrhea
- mutations of alternative complement pathway - factor H, factor I, CD46
- poor prognosis, commonly progressing to end-stage renal disease
- Tx: plasma exchange
13
Q
Approach to the pt with thrombocytopenia
A
- history: drug, infection, vaccine, nutrition, family hx
- examine ocular fundus for evidence of CNS bleeding
14
Q
Glanzmann’s Disease
A
- deficiencies of the fibrinogen receptor alpha-IIB, beta-3
- bleeding of mucosa, skin, etc
- tx: avoid meds that affect platelet function, treat the anemia, platelet transfusion in bleeding patients
15
Q
Bernard-Soulier Syndrome
A
- hereditary platelet disorders characterized by thrombocytopenia, giant platelets, qualitative platelet defects
- decreased expression of GPIb/IX/V
- autosomal recessive
- easy bruising, bleeding, purpura, petechial rash
- Tx: supportive
