Hemodynamic Disorders I & II - Parsa Flashcards
Total Body Water
40 L (60% of body weight)
Intracellular fluid
25 L (40% of body weird) (2/3 TBW)
Extracellular fluid
15 L
Interstitial fluid
12 L (75% ECF)
Plasma
3 L (25% ECF)
Edema
Excess accumulation of fluid in the interstitial tissue space
What does hydrostatic pressure do?
- Forces fluid out
* high at arteriolar end of the capillary bed
What does plasma colloid osmotic pressure do?
- Draws fluid into the capillaries
* High at venous end of capillary bed
What is localized edema?
- Inflammation
- Allergic reaction
- Venous obstruction
- Lymphatic obstruction
What is an example of lymphatic obstruction?
Inguinal lymphatic obstruction due to filariasis (elephantiasis)
What is generalized edema?
- Congestive heart failure: increased hydrostatic pressure
- Hypoproteinemia: decreased oncotic pressure due to decreased protein in blood from liver or kidney damage.
- Sodium retention
What is anasarca?
Severe edema throughout entire body
What is hyperemia?
- Inflammatory associated diseases
- Increased inflow of blood as a result of arteriolar vasodilation
- Tissues appear redder and warmer
What is congestion?
- Increased blood volume due to impaired venous outflow
- Unoxygenated blood backs up
- Results in cyanosis and dusty coloration
- Typically due to heart failure
What results from left-sided heart failure?
- Pulmonary edema
- Acute: MI
- Chronic: hemosiderin-laden macrophages (heart failure cells) in alveoli
What results from right-sided heart failure?
- Pooling of blood on to venous side of circulation
- Can be secondary to lung disease or left-sided heart failure
- Can mess up liver (“nutmeg liver”)
What is a hemorrhage?
Vascular rupture due to: trauma, atherosclerosis, congenital aneurysms, inflammatory conditions and erosion by a mass
What is a hematoma?
A hemorrhage contained within a tissue or body cavity
What is hemostasis?
Arrest of blood flow
What is the primary platelet plug and when is it formed?
- Platelets aggregating and binding to site of endothelial injury
- First thing that happens after injury
What is the definitive platelet plug and when is it formed?
- Formed after primary platelet plug
- Formed as a result of activation of coagulation cascade
- Platelets + coagulants
What happens during the coagulation cascade?
- Prothrombin → thrombin
- Thrombin catalyzes cleavage of fibrinogen to fibrin
- Fibrin helps created definitive platelet plug
What is thrombosis?
- The process of thrombus formation
- A result of dysregulation or imbalance between pro and anti coagulation mechanisms
- Normal hemostasis, but in an abnormal location
What are some inhibitors of thrombosis?
- Heparin-like molecules
- Thrombomodulin
- Tissue factor pathway inhibitor
What are some activators of thrombosis?
- Endothelial injury
* Tissue factor
Does a blood clot use platelets? Coagulation cascade? Both?
Coagulation cascade ONLY
What is a thrombus?
A solid mass formed by both the platelet and coagulation mechanisms
What things promote thrombus formation (aka Virchow Triad)?
- Endothelial injury
- Abnormal blood flow
- Hypercoagulability
What are the 3 types of thrombosis?
- Arterial
- Cardiac
- Venous
What is arterial thrombosis?
- Thrombii located in an artery
- Usually occurs with atherosclerosis
- Thrombus grows in opposite direction of blood flow
What are some common sites for arterial thrombosis?
Cerebral, coronary and femoral arteries
What is cardiac thrombosis?
- Aka mural thrombi because they attach to the wall but don’t block the lumen
- Thrombii located in ventricles, atria or aorta
- In microscopy, look for “Lines of Zahn” or layered appearance
What is venous thrombosis?
- Thrombii located in the veins
* Can be superficial (SVT) or deep (DVT)
SVT
- Common in greater or lesser saphenous veins
- Secondary to varicose vein formation
- More common in lower extremities
- Symptoms include: pain, warmth, edema, tenderness
DVT
- Prone to embolism
- Common in lower extremities
- Harder to recognize
- Milking movement of veins by leg muscles causes thrombi to break off and embolize
So you’ve got a thrombus, now what can happen?
- It can dissolve by the fibrinolytic system
- It can continue to grow or propagate until it occlude the lumen
- It can recanalyze
- It can embolize
What can you take to prevent a thrombus?
- Aspirin: blocks platelet aggregation
- Coumadin
- Heparin: inhibits coagulation
- Plasmin: breaks down fibrin (clots)
Exudate fluid type
- Damage to integrity of vessel without bursting
- Results in increased vascular permeability or due to the action of inflammatory mediators
- Cloudy, turbent appearance with proteins present
Transudate fluid type
- Due to non-inflammatory causes like renal failure, chronic liver disease, or congestive heart failure
- Due to increased hydrostatic pressure, decreased oncotic pressure or lymphatic obstruction
- No change in vascular permeability
- Get clear yellow fluid
- Just water and maybe some electrolytes getting out; no proteins
