Hemostasis Flashcards
Define edema
Accumulation of interstitial fluid in tissues, including subcutaneous tissues and body cavities
What is anasarca?
Very severe generalized edema
What is the most common cause of lymphatic obstruction (lymphadema)?
Post-surgical or post-radiation therapy scarring/removal of lymph channels.
Name 4 general pathopysiologic causes of edema
- Increased capillary hydrostatic pressure due to arterial dilation or impaired venous return
- Reduced plasma osmotic pressure due, possible due to excessive loss of albumin (nephrotic syndrom, protein-losing enteropathy, malnutrition, liver disease/cirrhosis)
- Lymphatic obstruction (lymphedema) due to inflammatory, neoplastic, or iatrogenic (surgery, radiation) processes
- Sodium (and water) retention due to excessive salt intake or acute reduction in renal function
Define hyperemia. Where does it occur?
Increase in blood volume within a tissue due to increased blood flow and arteriolar dilation. Hyperemia is an active process that commonly occurs at the site of inflammation or in exercising skeletal muscles.
Define congestion. Where does it occur?
Increase is blood volume in a tissue due to impaired/decreased outflow of venous blood (passive process).
Examples:
Systemic: liver and lung congestion due to heart failure
Local: obstruction of superior saggital sinus
List the general steps in primary hemostasis (5)
- Platelet adhesion
- Platelet shape change
- Platelet granule release
- Recruitment
- Aggregation and formation of hemostatic plug
Name the general steps in secondary hemostasis (4)
- Tissue factor release
- Phosphlipid complex expression
- Thrombin activation
- Fibrin polymerization
What does Prothrombin time (PT) measure?
Extrinsic pathway + common pathway
What does Activated Partial Thromboplastic time (aPTT) measure?
Intrinsic pathay + common pathway
Hemophilia A features a defect in what clotting factor? Hemophilia B?
A: Factor VIII
B: Factor IX
Which clotting factors are dependent on vitamin K?
Factors 2, 7, 9, 10
Name the hemodynamic disease matching each of the following bleeding disorder mechanisms or descriptions:
- Factor 9 deficiency
- General factor deficiencies or dysfunction
- Inherited defect in platelets causing a deficiency of gpIIb/IIIa expression on platelet membranes
- Too few platelets
- Vitamin C deficiency leading to vessel fragility (collagen synthesis issue)
- von Willebrand factor deficiency or dysfunction
- Platelet and clotting factor consumption due to systemic clotting followed by systemic bleeding
- Deficiency of factors 2, 7, 9, 10
- Factor 8 deficiency
- Hemophilia B
- Liver disease
- Glanzmann’s thrombasthenia
- Thrombocytopenia
- Scurvy
- von Willbrand disease
- Disseminated Intravascular Coagulation (DIC)
- Vitamin K deficiency (or Warfarin therapy)
- Hemophilia A
What is hemorrhagic diathesis?
A predisposition to hemorrhage, even with minimal trauma
Define hematoma
Accumulation of blood within a tissue
Define and describe: petechial hemorrhage
1-2mm hemorrhage, usually into skin, mucous membranes, or serosal surfaces. Petechiae can be associated with low platelet counts (thrombocytopenia), platelet dysfunction, loss of vascular wall support, or local pressure.