Sepsis Flashcards
define sepsis
life threatening organ dysfunction caused by dysregulated host response to infection
define septic shock
sepsis with persisting hypotension requiring vasopressors to maintain MAP >65mmHg and having serum lactate of >2mmol/l despite adequate volume resuscitation
what scoring system can be used to assess a patient (>18yrs) with a suspected infection their risk of needing a prolonged stay in the ICU ?
qSOFA
what are the categories for the qSOFA scoring system?
> altered mental state
hypotension (systolic BP less than 100mHg)
tachypnoea (>22/min)
a qSOFA outcome of more than two suggest what?
a poorer outcome
define SIRS ( septic inflammatory response syndrome)
2 or more of the following features:
> temperature less than 36C more than 38C
more than 90 bpm
resp. rate.: more than 20 b/min
PaCO2 less than 4.3kPa
WBC: less than 4 X 10^9
more than 12 X 10^9
what features may be present consistent with immunosuppression?
> loss of delayed hypersensitivity
inability to clear infection
predisposition to nosocomial infections
what is the first phase of the pathophysiology of sepsis?
release of bacterial toxins
what bacterial toxin is released by gram negative bacteria?
lipopolysaccharide
what bacterial toxin is released by gram positive bacteria?
> super-antigens (streptococcal exotoxins, staphylococcal toxic shock syndrome)
> microbial associated molecular pattern (lipoteichoic acid, muramyl dipeptides)
what is stage 2 of the pathophysiology of sepsis?
release of mediators in response to infection
stage 2 pathophysiology
describe the gram negative endotoxin release
produce lipopolysaccharides which need a binding protein to bind to macrophages
gram positive organisms produce lipoteichoic acid in stage 2. do they need a binding protein to bind to macrophages?
no
describe exotoxin release in stage 2 pathophysiology
small amounts of super-antigens produce large amounts of mediators to be secreted creating a cascade effect leading to a cytokine storm (patients can die within a few hours)
what do pro-inflammatory mediators lead to?
septic shock