Hemodynamics 1 Flashcards
What is edema?
Swelling of tissue due to increased fluid in interstitial tissue spaces. Can be localized or generalized.
What is the most common cause of edema?
Heart failure
Why is ascites?
Fluid in the abdominal cavity
What is anasarca?
Generalized Edema
What is the first sign of Nephrotic Syndrome?
Periorbital Edema, frequently seen in 2 to 6 yo.
What are the five pathophysiologic categories of edema?
Increased hydrostatic pressure Decreased osmotic pressure Lymphatic obstruction Sodium retention Inflammation
In edema due to increased hydrostatic pressure, why does it occur in the leg? The lungs? The lower body in general?
In a leg due to deep venous thrombosis
in the lungs due to left heart failure
In the lower body due to right heart failure
How are hydrostatic pressure-caused edema and sodium retention edema linked?
When heart failure causes decreased renal blood flow, it activates the renin-angiotensin-aldosterone system. Increased aldosterone causes retention of sodium and water, which causes edema leading to two types of edema at the same time.
What is a symptom of nephrotic syndrome?
Edema from decreased osmotic pressure due to protein loss through the kidneys.
How is edema from hepatic cirrhosis caused?
- Due to increased hydrostatic pressure from the portal venous system
- Decreased osmotic pressure due to low albumin levels.
Is edema due to sodium retention localized or generalized?
Always generalized, and caused by heart or renal failure
What is lymphedema?
Edema of the lymph channels due to obstruction, frequently cancer, inflammation, surgery, radiation or scar.
What is the cause of pulmonary edema?
left heart failure (most common) or renal failure
What are the major symptoms of pulmonary edema?
Dyspnea (major symptom) Pulmonary Crackles (major sign)
What is the difference between hyperemia and congestion?
Both are increased blood volume, one due to increased arterial output, the other due to decreased venous return.
What is the visible difference between hyperemia and congestion?
Hyperemia frequently results in a redness, while congestion is cyanotic.
What is most commonly the reason for nutmeg appearance of the liver?
Inadequat arterial perfusion of the liver
What are petechiae?
Tiny (1-2 mm) hemorrhages due to platelet deficiency.
What are purpura?
Medium hemorrhages (3-10mm) due to vasculitis
What are ecchymoses?
Over 1 cm subcutaneous hemorrhages that go from red-blue to blue-green to gold-brown (bruises)
What is hemostasis as commonly used?
Hemostasis refers to the formation of clots at a site of vascular injury
What are the three regulatory components of hemostasis?
1 Vascular wall (endothelium
2 platelets
3 coagulation cascade
What are platelets?
Cellular components of blood, anucleate pieces of megakaryocyte cytoplasm important in initation and propagation of clotting.
What do platelets contain that assist clotting?
ADP, Fibrinogen, Clotting factors (5 and 8), calcium and epinephrine
What is the first stage of hemostatis?
Vasoconstriction
What is the second stage of hemostasis?
Primary hemostasis, platelet adhesion to thrombogenic ECM. Mediated by von Willebrands factor, binding to their GpIb receptors. Platelets change shape from oval to spiky to aggregate. Receptors bind fibrinogen.
The conformational change and accumulation of platelets is associated with what?
The release od ADP and thromboxane A2 from platelets, which cause additional recruitment and aggregation
What is the third state of hemostasis?
The coagulation cascad by tissue factor and platelet factors.Culminates in conversion of fibrinogen to fibrin. The release of Thromboxane A2, activates monocytes and lymphocytes and stimulates endothelial cells to adhere neutrophils and release NO.
What is stage 4 of hemostasis?
Thrombus stabilization and antithrombotic events
What does deficiency in von Willebrands factor lead to?
Excessive bleeding during surgery or menstruation.
What does overactivity of Von Willebrands factor lead to?
Excessive clotting in small blood vessels, and then bleeding from having used too many platelets and clotting factors.
What is thrombosis?
Inappropriate formation of clotting in vessels, usually occlusive.
What are three predisposing factors of thrombosis?
Endothelial injury (most important)
Abnormal Blood flow
Hypercoagulability
How does abnormal blood flow lead to thrombosis?
Either turbulence or stasis allows blood to have moments of stasis, promoting platelet adhesion.
In normal blood flow, where are platelets found
Near the center of the vessel, moving to the outside during stasis or turbulent blood flow.
What are examples of acquired hypercoagulable states?
Surgery, Cancer, Trauma, Bed-ridden state, heparin induced thrombocytopenia
What are examples of genetic hypercoagulable states?
Factor V Leiden Mutation
Prothrombin Mutation
Protein C deficiency
What is Factor V Leiden Mutation
Mutation in clotting factor V makes it resistant to activated protein C, resulting in loss of an important clot-limiting counter-regulatory mechanism
What are the three types of thrombi?
Arterial, Venous and Mural
Arterial thrombi are rich in what?
Platelets
Venous thrombi are right in what?
RBCs
What are mural thrombi?
Thrombi located in the walls of your heart
What are thrombi on the heart valves called?
Vegetations
What are the four stages of thrombus?
Dissolution
Propagation
Embolization
Organization (recanalization)
What is organization of a thrombus?
Ingrowth of fibroblasts, who convert thrombus to fibrous tissue, with ingrowth of new capillaries.
What is an embolus?
Detached intravascular solid, liquid or gas carried to a distant site.
What are the various types of embolus?
Thrombus, Atheromatous debris, fat, air, amniotic fluid and fragments of a tumor
When is fat embolism common?
In long bone fracture
What is the difference between white and red infarcts?
White (anemic) infarcts are in tissues with end-arteriolar blood supply. Red is frequently seen in areas with dual blood supply or venous occlusion, due to present of new blood.
