13. bleeding disorders Flashcards
(38 cards)
Haemostasis
Mechanism which maintains the integrity of the circulatory system after vascular damage
haemostasis achieved by
vessel constriction platelet plug (primary haemostasis) activation of the coagulation cascade and fibrin deposition (secondary haemostasis)
Lab for primary hemostasis
Platelets count
Bleeding time
Platelets function assay
Platelets agrigometry
PM and BM study
normal PTT and PT time
PTT 25-37
PT 10-13
If ptt increased and pt normal problem in
intrinsic
if ptt and pt increase
common pathway
if ptt normal and pt increase
extrinsic pathway problem
which factor has longest and shortest half life
longets factor 2
shortest factor 7
The clinical significance of hemorrhage depends on
Volume of the bleed – rapid loss > 20% of the blood volume can cause hemorrhagic (hypovolemic) shock,
Rate of bleeding – chronic or recurrent external blood loss results iron deficiency anemia
Location – trivial in subcutaneous tissues vs deadly in the brain
Defects in blood vessel
Vasculitis
Scurvy
Amyloidosis
Malignant HTN
Uterine atony
henoch scholein purpura clinical manifestation
palpable purpura
joint pain
blood in urine
pain in abdomen
primary heamostasis defect because of
defect in platlet either qualitatively or quantitavily
von willebrand diesease both
qualitative defect in platelet divided into 2
genetic and acquired
genetic qualitative defect in platelet
Bernard-Soulier syndrome
Glanzmann thrombasthenia
Bernard-Soulier syndrome
defect in glucoprotein Ib-IX-V
enlarged platlets
Glanzmann thrombasthenia
defect in glycoprotein IIb-IIIa
acquired qualitative defect in platelet
uremia
drugs - asprin
quantitative defects include
thrombocytopenia
idiopathic thrombocytopenic purpura
thrombotic microangiopathy - ttp - hus - dic
waterhouse fridrichsen syndrome
trousseaus syndrome
Thrombocytopenia
(< 150,000 platelets/μL)
causes of thrombocytopenia
decreased production
ineffective production
increased destruction
increased sequestration
dilution
idiopathic thrombocytopenic purpura
primary immune thrombocytopenia
pathogenesis antibody against platlet antigen
thrombotic microangiopathy divided into
ttp
hus
dic
thrombotic thrombocytopinic purpura ttp
low ADAM13 (cleaves von wille)
platelet aggregation
lysis
5 characteristics of ttp
fever
thrombocytopenia
microangiopathic hemolytic anemia
neurologic
renal failure