sepsis Flashcards
what is sepsis?
Sepsis is a life threatening condition that arises when the body’s response to an infection injures its own tissues
what is septic shock?
) Septic shock is a subset of sepsis where profound circulatory, cellular and metabolic abnormalities substantially increase mortality
whats the difference between gram positive and gram negative in the classification of bacteria?
Gram positive (G+) bacteria have a cell wall comprising mainly of peptidoglycan
Gram negative (G-) bacteria have a thin layer of peptidoglycan sandwiched between two membranes
what is bacterial sepsis caused by?
what happens in bacterial sepsis?
Caused by a wide variety of bacterial mechanisms
Most common is lipopolysaccharide (LPS)
75% of bacterial cell membrane
Induces inflammatory cell to produce pro-inflammatory mediators
Interleukins (IL-1, -1b, -6, -8, -12)
Tumour necrosis factor a (TNF-a)
Causes tissue damage
Pro-inflammatory
IL-1 potent mediator of increased vascular permeability
what are the gram positive bacteria names?
Staphylococcus aureus
Salmonella species
Clostridium difficile (spore forming)
SSC
what are the gram negative bacteria names
Escherichia coli
Helicobacter pylori
Pseudomonas aeruginosa
Acinetobacter baumannii
EHPA
what are the 3 stages of inflammation?
Vasodilation, caused by inflammatory mediators leading to tachycardia, hypotension and inadequate organ perfusion.
Increased vascular permeability, leads to ‘leaky’ capillaries with intravascular volume leaking into the extravascular space.
Increased oxygen demand from the cells. Demand can increase 12-fold in sepsis, but cardiac output can only increase up to 5-fold to compensate.
what does nitric oxide do?
causes and maintains vasodilation.
makes the capillaries more permeable (leaky)
what does bradykinin do?
responsible for the pain at the site of inflammation, and also involved in vasodilation and making capillaries more permable
whats the function of complement protiens?
act directly to neutralise pathogens, mobilse white blood cells and amplify the immune response
what is the function of thombin
helps clot formation by turning fibrinogen into fibrin
what do interleukins do?
complex group of protiens help white blood cells to function, attract them to the area and modulate inflammation
what does tumour necrosis factor do
pro inflammatory cytokine
what does these terms mean
rubor
tumor
calor
dolar
redness
swelling
heat
pain
what is the autonomic (sympathetic) regulation of GFR
Occurs during compensation phase
Overrides renal autoregulation
Maintains blood flow to heart, brain, muscles at expense of GFR
Sympathetic response - release of adrenaline from adrenal medulla
Causes greater constriction of afferent arteriole than efferent arteriole so
Glomerular hydrostatic pressure reduced
GFR reduced
