Primary hemostasis disorders Flashcards
Primary hemostasis disorders
vascular disorder
Platelet disorder
Secondary hemostasis disorders
Coagulation factor disorders
Fibrinolytic disorder
Primary hemostasis characteristics
“superficial bleeding at the surface” –> mostly skin and mucous membrane bleeds
Epistaxis
nose bleed
petechiae
pinpoint bruising
purpura
bleed under the skin resulting in larger flat areas (bruises)
PH bleedings
prolonged bleeding of minor cuts
spontaneous gingival bleeds
Mostly skin and mucous membrane bleeds
primary hemostasis
Vascular phase disorders
Before platelet plug forms, excess RBCs leave vessel and start to pool under skin or mucous membrane.
Vascular phase disorders
Primary Purpura
Secondary Purpura
Vascular and connective tissue disorders
Primary purpura
Disorders that results in bruising not associated with any specific disease
Mild bruising with minimal trauma.
Example: Bruising from sneezing, light physical touch, loss of subcutaneous tissue.
Secondary purpura
result of another disease process
Ex: infections or allergic reactions
Metabolic imbalances (Scurvy - Vit C def.)
Abnormal blood vessel structure –> leads to increased blood permeability
example of vascular and connective tissue disorder
Hereditary hemorrhagic Talangiectasia (HHT)
HHT disease
Arteries and veins become abnormally connected
Development of telangiectasis (red line patterns) on mucous membranes and skin
Lesions develop on the tongue, lips, palate, face, hands, nasal mucosa and GI tracts
Quantitative disorders
Thrombocytopenia
Thrombocytosis
Qualitative PLT disorder
Congential disorders of PLT function
- PLT membrane
- PLT secretion
- Coagulation
Acquired qualitative platelet disorders
Related: von Willebrand Disease
Thrombocytopenia
Platelets must be present in adequate numbers to maintain normal hemostasis
Thrombocytopenia: <150,000/ul
PLT<60,000/ul
unexpected bleeding
PLT<10,000/ul
spontaneous bleeding/hemorrhaging
thrombocytopenia is due to
deficient platelet production
Myelophthsisc conditions
BM is infiltrated
aplasia
BM is hypocellular (mostly fat)
Ineffective erythropoiesis (and thrombopoiesis)
megaloblastic anemia
Congenital disorders, examples
May Hegglin
Chediak Higashi
Bernard-Soulier
Thrombocytopenia: May-Hegglin Syndrome
Inherited PLT disorders, resulting in abnormally large and misshapen platelets (giant platelets)
WBC have increased Doyle-like bodies
May Hegglin syndrome
Hypersplenism
Spleen normally sequesters 30% of platelets
When it is enlarged (splenomegaly), it sequesters more
Kasabach - Merit Syndrome
Rare disorder with giant hemangiomas (vascular tumors) that are believes to be sequestering platelets from circulation
Immune (idiopathic) thrombocytopenia purpura (ITP)
autoantibody to self-platelets
post transfusion purpura
alloantibody to donor platelets
neonatal isoimmune purpur a
maternal antibody to baby platelets
drug induced thrombocytopenia
drug bound antibody to self platelets
Heparin induced thrombocytopenia and thrombosis
abnormal antibodies formed that activate platelets and get used up making non-needed clots.
secondary immune platelets destruction disorders
All present with ITP-like thrombocytopenia that is due to some other disease process
- SLE
- Infections (viral - HIV, hepatitis), or parasitic (malaria)
- Lymphoproliferative disorders (Hodgkins, non-hodgkins lymphoma)
TTP - Thrombotic Thrombocytopenic Purpura
Fibrinolysis inhibited + deficiency in ADADMTS-13, leads to increased platelet aggregation and thrombosis
Hemolytic Uremic Syndrome (HUS)
Infection by E.Coli O157;H7 or others that lead to platelet destruction, anemia, acute kidney failure.
Disseminated Intravascular Coagulation (DIC)
Accelerated platelet destruction + coagulation factor consumption (micro thrombi)
Thrombocytopenia: increased platelet destruction
Results in:
Microangiopathic thrombocytopenia
- conditions that result in thrombosis (blood clot formation) in small vessels (capillaries and arterioles)
Thrombocytosis - PLT count
> 450,000 PLT/ul
Primary thrombocytosis
often due to myeloproliferative disorders
Platelet proliferation is not due to thrombopoietin levels
Reactive thrombocytosis
Often caused by a reaction to something and can either be transient or chronic
acute hemorrhage
platelet counts increase after to try to replenish lost
TRANSIENT
post splenectomy
spleen no longer sequestering platelets
CHRONIC
Drugs
Epinephrine causes rapid transient increase
qualitative disorders of platelet function
congenital
Platelet membrane problem
Bernard soulier syndrome
Glanzmanns thrombasthenia
secretion release problem
storage pool deficiency
primary secretion defects
Bernard Soulier syndrome
deficiency of platelet GPIb/IX complex
Rare
Bleeding due to :
- thrombocytopenia
- Abnormality of platelet-vWF binding in platelet adhesion
abnormality of platelet - thrombin interaction
Glanzmann Thrombobasthenia
Deficiency of platelet GPIIb/IIIa receptor (needed for fibrinogen bridges)
Deficiency causes abnormal clot retraction –> patient forms loose clot
Secretion release problem - storage pool deficiency
granule proteins present/absent and platelet morphological appearance
Gray-platelet syndrome
deficiency of alpha granules with granular appearance of platelets
dense granule deficiencies
associated with congenital abnormalities including Oculocutaneous albinism
hermansky - pudlak syndrome
neutropenia, pulmonary fibrosis, prolonged bleeding
Chediak Higashi
Oculocutaneous albinism + dense granule deficiency + thrombocytopenia
GIANT AZUROPHILIC GRANULES in WBC
secretion defects
- due to enzymatic pathway
- granules are present, but not released properly
- presentation is similar to storage pool deficiencies
Platelet coagulation defects
PLT disorders that result in thrombin not being generated
rare!
symptoms close to hemophilia
non-immune cause
PLT dysfunction by systemic illness or medication
more common than congenital qualitative PLT disorders
EX of qualitative PLT disorders
Uremia (renal disease)
Liver disease
Paraproteinemias - excess immunoglobin proteins (MM, WM)
Myeloproliferative disorders - PV, idiopathic, myelofibrosis, essential thrombocyothemia
Von willebrand disease
Most prevalent inherited bleeding disorder worldwide
- inherited deficiency of vWF
- often confused with primary PLT disorder
- missing VIII:vWF
vWF disease classified:
by ABO blood type, lowest in O
type 1 = 70-80%, quantitative decrease in vWF, mild bleeding
type 2 = 15-20%, qualitative abnormality in vWF structure, mild to moderate bleeding
type 3 = very rare, absent levels of vWF, severe bleeding, similar to hemophilia A
