Thrombosis Embolism and Shock Flashcards
Define thrombosis
the formation of a solid or semi-solid mass from the constituents of the blood while moving within the vascular system during life
Where do thrombi form?
Lumen of the heart
Arteries
Veins
Capillaries
What is the name of the triad that describes the factors that promote thrombosis?
Virchow’s Triad:
abnormalities of the vessel wall
abnormalities of blood flow
abnormalities of the blood’s constituents
Abnormalities of the vessel wall include…
Atheroma Inflammation MI Rheumatic endocarditis Vein trauma
Abnormalities of blood flow include…
Aneurysms, plaques and spasms
Atrial Fibrillation
Vein compression and inactivity from post-op bed rest, heart failure and circulatory shock
Abnormalities of the blood constituents include…
Increased viscosity: caused by polycythaemia, dehydration, chronic hypoxia, polycythaemia rubra vera, multiple myeloma
Abnormalities of clotting from:
pregnancy, contraceptive pills, trauma
What is the fate of thrombi?
Fibrinolysis - forms into a scar by macrophages and fibroblasts, vessel lumen remains narrowed. Detatches as a thromboembolism.
Define embolism
The transport of abnormal material by the blood stream and its impacting in a blood vessel.
What are the types of emboli?
Thrombi Fat - multiple bone fractures Gas - infusions, vascular surgery Tumour material - mets Infective agents Atheroma Amniotic fluid Foreign bodies - IV drug abuse
Define shock
A physiological state characterised by a reduction in tissue perfusion, resulting in decreased tissue oxygen delivery and insufficient removal of cellular metabolic products, resulting in tissue injury.
What is hypovolaemic shock?
Caused by haemorrhage - internal or external.
Severe burns
What is cardiogenic shock?
Large acute MI
Other acute cardiac disease
What is septic shock?
endotoxins and exotoxins from bacteria both lead to dilation of blood vessels
What is anaphylactic shock?
Severe form of allergic reaction
What is neurogenic shock?
Spinal cord trauma
