Define the process of thrombosis.
Thrombosis: the result of activation of the clotting mechanism within the cardiovascular system, in a living person
Can seal a rupture or be inappropriate
Understand the difference between thrombosis and hemostasis.
Thrombosis: pathologic process; inappropriate intravascular clotting in a living person
—Clot formation on UNINJURED epithelium
Hemostasis: normal process; blood maintained clot-free; hemorrhage is stopped by sealing blood vessels after rupture
Discuses the most encountered cases of thrombosis. (4)
- Ventricular mural thrombosis: caused by injury to endocardium and decreased flow following an MI
- Thrombosis of heart valves: caused by endothelial injury due to infective endocarditis, rheumatic (autoimmune) endocarditis, or trauma -> hypercoagulable states
- Venous thrombosis:
- -Phlebothrombosis: due to stasis of blood in uninflamed veins, sometimes aggravated by hypercoagulability
- -Thrombophlebitis: thrombosis in inflamed veins, due to trauma, radiation, chemicals, or bacteria
- -Parts can break off -> pulmonary embolism - DIC (discussed in other lectures)
Define the outcomes of thrombosis, particularly venous thrombosis. (4)
Lysis (dissolution) = resolution
Organization in connective tissue
Propagation towards the heart
Embolization to lungs
Define the process of embolism and its clinical outcomes.
Embolism: obstruction of an artery by a detached mass carried by the bloodstream to a distant site from its point of origin
Causes: blood clot, atheroma, fat, bone marrow, tumor, air, foreign substances
Outcomes: differ if systemic vs pulmonary circulation
—Potentially -> infarction
Discuss the causes and clinical outcomes of thromboembolism.
Cause: part of a dislodged thrombus, generally from leg -> pulmonary circulation
Outcomes:
- Silent small pulmonary emboli
- Sudden death from large pulmonary emboli
- Hemorrhage in lungs from medium sized emboli
- Infarction of lower extremities
- Stroke
Discuss the causes and clinical outcomes of cholesterol embolism.
Cause: atherosclerotic debris
Outcomes: ischemia
Discuss the causes and clinical outcomes of decompression sickness.
Cause: bubbles of oxygen or nitrogen -> physical obstruction of arteries/atria; from diving, obstetric procedures, or large chest trauma
Outcomes:
- Pain
- Focal ischemia
- Trouble breathing
-Persistence -> Caisson disease -> focal necrosis in skeletal system
Discuss the causes and clinical outcomes of fat embolism.
Cause: droplets of fat that enter circulation and obliterate an artery; from fractures, trauma, or burns
Outcomes:
- Usually silent
- Severe if in brain or lungs and big enough
Discuss the causes and clinical outcomes of amniotic embolism.
Cause: amniotic fluid/fetal masses enter maternal circulation during labor or immediately after
Outcomes:
-20-40% mortality rate
List a possible cause of foreign body embolism.
Cause: things like bits of bullets
Define shock as a cardiovascular disorder.
Inadequate perfusion of cells and tissues
Due to decreased ECV and/or decreased CO
Discuss the three progressive phases of shock pathogenesis.
- Nonprogressive/compensated: compensatory mechanisms maintain CO and BP, enabling perfusion of heart and brain
- Progressive, still reversible: generalized hypoperfusion and worsening of circulatory and metabolic imbalances
- Irreversible: severe tissue/cellular injury -> multiple organ failure and death even in the conditions of correction of hemodynamic defects
Name the types of shock encountered in clinic and discuss the causes. (5)
Hypovolemic shock: hemorrhage, diarrhea, dehydration, burns
Cardiogenic shock: MI, myocarditis, cardiac tamponade, pulmonary embolus
Anaphylactic shock: Type 1 HS
Neurogenic shock: brain damage, spinal cord injury, anaesthesia accidents
Septic shock: severe infection
Define clotting.
Coagula that form outside of blood vessels or in blood vessels postmortem
Define stasis.
Decreased blood flow
Define phlebothrombosis.
Venous thrombosis
Due to stasis of blood in uninflamed veins
List the causes of thrombosis resulting from endothelial injury (5), abnormal blood flow (2), and hypercoagulability (2). (Do NOT need to know examples in () )
Endothelial injury:
- Loss of endothelial cells (mural thrombus formation)
- Inflammation (arteritis, phlebitis)
- Anatomic alterations (atherosclerotic plaques)
- Trauma or surgery
- Endothelial dysfunction (bacterial endotoxins, HTN, cigarette smoke)
Abnormal blood flow:
- Stasis (bed rest, fibrilitic atria, venous thrombosis)
- Turbulence (aneurism, arterial bifurcations)
Hypercoagulability:
- Primary/genetic (Factor V Leiden, prothrombin G20210, protein C or S deficiency)
- Secondary/acquired (Cardiac failure, OCP, disseminated cancer, increased platelets, smoking
