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
what so compensatory anti-inflammatory mediators lead to?
immunoparalysis
what is phase 3 of the pathophysiology of sepsis?
effects of specific mediators
what are the effects of anti-inflammatory mediators in stage 3?
> inhibit TNF alpha
augment cute phase reaction
inhibit activation of anticoagulation system
creates negative feedback of proinflammatory mediators
what are the effects of pro-inflammatory mediators?
> hyperthermia
promotes endothelial leukocytes adhesion
releases arachidonic acid metabolites
vasodilation via NO
increases coagulation (tissue factor release and membrane coagulants)
what does the clinical manifestation of sepsis depend on?
> environment (travel, hospitalisation, occupation)
> organism (virulence factor and bioburden)
> host (immunosuppression, comorbidities, splenectomy, age)
what are the general features of sepsis?
> fever more than 38C > hypothermia less than 36C (elderly and young) > tachycardia more than 90 > tachypnoea more than 20 > altered mental state > hyperglycaemia more than 8 mmol/l
what inflammatory variables can present in sepsis?
> leucoytosis > leucopenia (immunocompromised) > normal WCC with >10% immature forms > high crp > high procalcitonin
what haemodynamic variables can present in sepsis?
> arterial hypotension (MAP <70mHg)
> SvO2 >70%
what organ dysfunction variables can present in sepsis?
> arterial hypoxaemia > increased creatinine > coagulation abnormalities > thrombocytopenia > hyperbilirubinemia > ileus (lack of digestive propulsion)
what tissue perforation variables can present in sepsis?
> skin mottling
capillary perfusion
increased lactate
Name sepsis 6
Blood cultures Blood lactate Urine output Oxygen IV antibiotics IV fluids
what is type A lactate a marker of?
generalised hypoperfusion
what is type B lactate a marker of?
> mitochondrial toxins
alcohol
malignancy
metabolism errors
what is urine output a marker of?
renal dysfunction
true or false
if the temperature spikes you should take 2 sets of blood cultures
true
what is your aim for oxygen concentration in a septic patient?
94%-98%
when should you refer your septic patient to HDU?
> decreasing BP unresponsive to fluids > lactate >2 > oliguria > liver dysfunction > elevated creatinine > bilateral infiltrates > hypoxaemia
when is a septic patient admitted to ITU?
> septic shock
> multiorgan failure
you see a patient with an increased resp. rate, BP 90/40 and who has not passed urine in 18 hours.
they have ashen skin and cyanosis of the lips as well as a non blanching rash.
are they high, moderate or low risk for sepsis?
high. you would also want to check from their history for objective evidence of altered mental state.
what in a patients history may put them at moderate risk of sepsis?
> history of altered metal state
acute deteriorating ability to function
impaired immune system
trauma, surgery, or invasive procedure in last 6 weeks
