Hem III and IV/Shock, Embolus, Necrosis Flashcards
What are the 3 main types of shock?
Cardiogenic shock, hypovolemic shock, and septic shock
What are the four main events in septic shock?
Vascular event (vasodilation, increased permeability)
Thrombotic (microvascular thrombosis, DIC)
Immunosuppressive (counter regulatory measure)
Metabolic (insulin resistance)
What produces the procoagulant state that can lead to thrombotic events in septic shock?
Endotoxins from the bacteria produce the procoagulant state
What causes adrenal insufficiency during shock?
Waterhouse-Friderichsen syndrome; it is adrenal hemorrhage and necrosis caused by DIC or endotoxin production from bacteria
What is disseminated intravascular coagulation (DIC)?
Concurrent microvascular thrombosis and fibrinolysis that occurs due to the procoagulant effects (from endotoxins of bacteria) and cytokines (TNF and IL-1) induce endothelial cells to make tissue factor leading to coagulation
What is the best screening test for DIC?
Elevated fibrin split products especially D-dimer
What is ARDS?
Adult respiratory distress syndrome. Combination of decreased cardiac output, vascular permeability and endothelial injury in the lungs.
What is the end result of septic shock (and what leads to mortality)?
End-organ damage
What are the 3 stages of shock?
- Nonprogressive phase where vital organ perfusion is maintained via reflex mechanisms
- Progressive stage where tissues are hypoperfused and acidosis sets in
- Irreversible stage where pronounced cell death is present
What is SIRS?
Systemic inflammatory response syndrome: nonspecific clinical response to either infection or noninfectious inflammatory process
What is bacteremia?
A blood infection without systemic response
What is acute tubular necrosis?
End-organ damage of the kidney, often due to shock
What is heparin-induced thrombocytopenia?
Platelet destruction due to heparin therapy; thrombosis results from destroyed platelets activating other platelets
How does fibrinolysis occur?
Tissue plasminogen activator converts plasminogen to plasmin, and plasmin cleaves fibrin and serum fibrinogen and blocks platelet aggregation
Why does cirrhosis of the liver lead to a disorder of fibrinolysis and plasmin overactivity?
Cirrhosis of the liver results in reduced production of alpha2-antiplasmin and thus overactivity of plasmin
What is the clinical laboratory difference between DIC and a disorder of fibrinolysis?
DIC has elevated D-dimers; in disorders of fibrinolysis, fibrin thrombi are not present thus D-dimers do not form
What is hyperemia compared with congestion? What is a classic case of congestion?
Hyperemia is an active process where tissues are engorged with blood due to arteriole dilation. Congestion is a passive process when blood flowing out of the tissue is reduced, so it backs up in the organ (example is nutmeg liver)
What are the 5 general causes of edema?
- Increase in hydrostatic pressure
- decreased plasma osmotic pressure
- sodium retention
- inflammation
- lymphatic obstruction
Compare and contrast exudate and transudate?
Exudate is protein rich and is a result of inflammatory edema; transudate is protein poor and a result of increased hydrostatic pressure or decreased osmotic pressure
What are vegetations in the heart?
Thrombi that are present on heart valves.
What are the four fates of a thrombus?
Dissolution
Propagation
Embolization
Organization
What is a fat embolism generally caused by? What is it characterized by?
Most commonly from long bone fractures; characterized by dyspnea and petechiae on skin overlying chest.
What is an air embolism generally caused by?
Air into an intravenous infusion or sudden change in atmospheric pressure (eg decompression sickness or bends due to scuba diving)
What causes an amniotic fluid embolism? What does the patient present with?
Enters maternal circulation during labor or delivery
