Bacteremia/Sepsis Flashcards
what are endotoxins a part of? when the body responds to the bacteria, what happens?
cell wall of gram-negative bacteria; it causes a cascade of events that leads to illness
what are exotoxins?
proteins released into the surrounding area by the bacteria during cell growth
what do exotoxins do to your body? what do they lead to?
enzymatically inactivate or modify key cellular parts, leading to cell death or dysfunction
what does botulism exotoxin do?
decreases the release of NT from cholinergic neurons causing flaccid paralysis
what does tetanus exotoxin do?
decreases the release of NT from inhibitory transmitters causing spastic paralysis
what does cholera exotoxin do?
induces fluid secretions into the intestinal lumen causing diarrhea
what is one specific category of exotoxins?`
superantigens
what happens when bacteria is engulfed by APCs? (normal process)
after ingested, epitopes are put on the cell surface, CD4 cells recognize the epitope, expansion of the specific CD4 cell and immunity to newly introduced antigen
what happens with exotoxins and APCs? what does this cause excessive activation of?
they do not get ingested by APCs, it binds directly to it and cross links with CD4 cells (activates up to 20% of lymphocytes); excessive activation of lymphocytes and macrophages (uncontrolled synthesis and release of inflammatory cytokines)
definition of infection
presence of bacteria with LOCAL inflammatory response
definition of bacteremia
presence of viable bacteria in the blood
definition of sepsis…what is it clinically characterized by
evidence of infection plus life threatening organ dysfunction, clinically characterized by an acute change in 2 pts or greater in SOFA score
definition of septic shock
sepsis with fluid, unresponsive hypotension, serum lactate level greater than 2mmol/L and needing vasopressors to maintain mean arterial pressure of 65mm Hg or greater
three things that can cause cardiogenic shock
MI, valve damage, surgery
three things that can cause hypovolemic shock
loss of whole blood, loss of plasma, loss of extracellular fluid
two things that can cause obstructive shock
inability to fill heart (tamponade) and embolus
three things that can cause distributive shock?
neurogenic shock, presence of vasodilating substances in the blood (anaphylactic shock), presence of inflammatory mediators (septic shock)
mortality is higher for pts who progress to ________ ________
septic shock