Difference between revisions of "Thrombocytopenia"
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(Created page with "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 ac...") |
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** Most Common Etiologies | ** Most Common Etiologies | ||
*** '''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 | *** '''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 | ** Pathogenesis | ||
*** Expression of the transmembrane glycoprotein TF (which activates factor VII and the extrinsic pathway) | *** Expression of the transmembrane glycoprotein TF (which activates factor VII and the extrinsic pathway) | ||
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*** Platelets are trapped in the clots | *** Platelets are trapped in the clots | ||
*** Plasminogen --> Plasmin also upregulated, leading to large increase in clot breakdown and release of [[FDPs]]. | *** 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 | ** Diagnostic Algorithm: Score of 5+ points strongly associated with DIC | ||
*** Presence of a disease known to be associated with DIC (2 pts) | *** Presence of a disease known to be associated with DIC (2 pts) | ||
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*** PT > 3s (1 pt), > 6s (2 pt) | *** PT > 3s (1 pt), > 6s (2 pt) | ||
*** Fibrinogen < 1 g/L (1 pt) | *** Fibrinogen < 1 g/L (1 pt) | ||
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** Treatments and Evidence Behind Them: | ** Treatments and Evidence Behind Them: | ||
*** Basically don't get it. | *** Basically don't get it. | ||
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*** Treatment is lousy. Evidence behind treatment is likewise lousy. | *** Treatment is lousy. Evidence behind treatment is likewise lousy. | ||
*** Platelets, cryo, FFP | *** Platelets, cryo, FFP | ||
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** Morbidity/Mortality is 20-50% | ** Morbidity/Mortality is 20-50% | ||
Revision as of 05:27, 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
- Most Common Etiologies
- 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
- Pathogenesis
- Expression of the transmembrane glycoprotein TF (which activates factor VII and the extrinsic pathway)
- Consumption of clotting factors
- Widespread micro and macrovascular thrombosis, depletion of fibrinogen and fibrin clot formation
- Platelets are trapped in the clots
- Plasminogen --> Plasmin also upregulated, leading to large increase in clot breakdown and release of FDPs.
- Diagnostic Algorithm: Score of 5+ points strongly associated with DIC
- Presence of a disease known to be associated with DIC (2 pts)
- Platelets < 100k (1 pt), < 50k (2 pt)
- Fibrin degradation products (FDPs) (e.g. d-dimer): moderate increase (2 pt), strong increase (3 pt)
- PT > 3s (1 pt), > 6s (2 pt)
- Fibrinogen < 1 g/L (1 pt)
- Treatments and Evidence Behind Them:
- Basically don't get it.
- Treat underlying condition
- Treatment is lousy. Evidence behind treatment is likewise lousy.
- Platelets, cryo, FFP
- Morbidity/Mortality is 20-50%
- Most Common Etiologies
- ITP
- TTP
- HUS
- HIT
Decreased Production
- LOW IPF%
- Parvo
- Aplastic Anemia
- Cancer
- Chemotherapy
- Liver disease?