Hemodynamic Derangements Flashcards
What are the clinical findings of HUS and TTP?
- Skin and mucousal bleeding
- Microangiopathic hemolytic anemia
- Fever
- Renal insufficiency (more common in HUS)
- CNS abnormalities (more common in TTP)
Vitamin K is activated by ________ in the liver.
Epoxide reductase
Hemophilia B
- Genetic factor IX deficiency
Treatment of ITP
- Corticosteroids (initial)
- Children respond well. Adults may show early response but often relapse
- IVIG (gives antibodies something else to bind to for a moment)
- Splenectomy
What are the laboratory finds of disorders of fibrolysis?
- Increased PT/PTT- Plasmin destroys coagulation factors
- Increased bleeding time with normal platelet count
- Increased fibrinogen split products without D-dimers
PT measures…
Extrinsic (VII) and common (II, V, X, and fribrinogen) pathways
How do endothelial cells prevent thrombosis?
- Block exposure to subendothelial collage and underlying tissue factor
- Produce PGI2 and NO (vasodilation and inhibition of platelet aggregation)
- Secrete heparin like molecules
- Augment antithrombin III (ATIII), which inactivates thrombin and coagulation factors
- Secrete tPA
- Secrete thrombomodulin
- Redirects thrombin to activate protein C, which inactivates factors V and VIII
HUS
- Due to damage by drugs or infection
- Seen in children with E. coli O157:H7 dysentery, which results from exposure to undercooked beef
- E.coli verotoxin damges endothelial cells resulting in platelet microthrombi
With anaphylatic, septic, and neurogenic shock, what happens to cardiac output and peripheral resistance?
Increase in CO
Decrease in peripheral resistance
Immune Thrombocytopenic Purpura (ITP)
- IgG against platelet antigens
- Antibodies are produced by plasma cells in the spleen
- Antibody-bound platelets are consumed by splenic macrophages; resulting in thrombocytopenia
___________ activates factor VII.
Tissue thromboplastin
With cardiogenic and hypovolemic shock, what happens to cardiac output and peripheral resistance?
Decrease in CO
Increase in Peripheral resistance
_________ normally stabilizies FVIII.
vWF
Vitamin K is important for which factors function?
II, VII, IX, and X, and protein C and S
NOTE: Activated vitamin K gamma carboxylates the above factors. Gamma carboxylation is necessary for factor function
What are the neurologic symptoms of ft and marrow embolism?
Irritable, Restless, Delirium and Coma
Laboratory findings of ITP
- Decreased platelet count
- Normal PT/PTT
- Increased megakaryocytes on bone marrow biopsy
Disseminated intravascular coagulation (DIC)
- pathologic activation of the coagulation cascade
- Widespread microthrombi result in ischemia and infarcation
- Consumption of platelets and factors results in bleeding, especially from IV sites and mucosal surfaces
treatment for disorders of fibrinolysis
Aminocarproic acid, which blocks activation of plasminogen
________________ inactivates plasmin.
a2- antiplasmin
Laboratory findings of DIC
- Decreased platelet count
- increase PTT/PT
- Decreased fibrinogen
- Microangiopathic hemolytic anemia
- Elevated fibrin slit products, particular D-dimer
Oral contraceptives are associated with a hypercoagulable state. Why?
Estrogen induces increased productopn of coagulation factors
Ristocetin test
- Ristocetin incudes platelet agglutination by causing vWF to bind platelet GPIb
- Lack of vWF, leads to impaired agglutination and an abnormal test
Cystathonine beta synthase deficiency
- Results in high levels of homocysteine
- Cystathonine converts homocystein to cystathonine
- Characterized by: Vessel thrombosis, mental retardation, lens dislocation, and long slender fingers
Glanzmann thromboasthenia
- Genetic GPIIb/IIIa deficiency