Difference between revisions of "Thrombocytopenia"

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* '''HIGH''' IPF%, Prolonged PT / aPTT
 
* '''HIGH''' IPF%, Prolonged PT / aPTT
 
* What happens to platelets after they help form a clot?
 
* What happens to platelets after they help form a clot?
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* [[DIC]]
 
* [[DIC]]
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** Most Common Etiologies
 
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*** '''Bacterial sepsis''' (83%), '''Trauma''' (31%), '''Cancer''' (e.g. APML, 6.8%), placental abruption, preeclampsia, amniotic fluid embolism, burn, hyperthermia, rhabdomyolysis, infection, transfusion reaction (ABO incompatibility), snake venom, aortic aneurysm
 
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** Pathogenesis
 
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*** Expression of the transmembrane glycoprotein TF (which activates factor VII and the extrinsic pathway)
 
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*** Consumption of clotting factors
 
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*** Widespread micro and macrovascular thrombosis, depletion of fibrinogen and fibrin clot formation
 
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*** Platelets are trapped in the clots
 
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*** Plasminogen --> Plasmin also upregulated, leading to large increase in clot breakdown and release of [[FDPs]].
 
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** Diagnostic Algorithm: Score of 5+ points strongly associated with DIC
 
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*** Presence of a disease known to be associated with DIC (2 pts)
 
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*** Platelets < 100k (1 pt), < 50k (2 pt)
 
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*** Fibrin degradation products (FDPs) (e.g. d-dimer): moderate increase (2 pt), strong increase (3 pt)
 
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*** PT > 3s (1 pt), > 6s (2 pt)
 
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*** Fibrinogen < 1 g/L (1 pt)
 
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** Treatments and Evidence Behind Them:
 
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*** Basically don't get it.
 
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*** Treat underlying condition
 
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*** Treatment is lousy. Evidence behind treatment is likewise lousy.
 
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*** Platelets, cryo, FFP
 
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** Morbidity/Mortality is 20-50%
 
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* ITP
 
* ITP
 
* TTP
 
* TTP

Latest revision as of 05:29, 21 October 2022

Platelets come from megakariocytes and are produced in bone marrow and lung. Their development is stimulated by thrombopoeitin produced in liver and kidney. They are 2-3 um across. Platelet function follows the pattern: Adhesion -> Activation -> Aggregation. Platelet aggregation forms a platelet plug (primary hemostasis), which is stabilized by coagulation factors culminating in a fibrin mesh/net which stabilizes the platelet plug.

Spurious

  • Clumping

Sequestration

  • Hypersplenism

Destruction/Consumption

  • HIGH IPF%, Prolonged PT / aPTT
  • What happens to platelets after they help form a clot?
  • DIC
  • ITP
  • TTP
  • HUS
  • HIT

Decreased Production

  • LOW IPF%
  • Parvo
  • Aplastic Anemia
  • Cancer
  • Chemotherapy
  • Liver disease?
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