Sepsis Flashcards
(25 cards)
sepsis definition
life threatening organ dysfunction due to a dyregulated host response to infection
bacteraemia
transient present of bacteria in bloodstream
septicaemia
persistent presence of bacteria in the bloodstream, with attendant signs and symptoms, need to act quickly and effectively, sepsis in bloodstream
SIRS - systemic inflammatory response syndrome
exaggerated defence response of the body to a stressor
SIRS diagnosis
temperature >38 < 36
heart rate >90BPM
respiratory rate >20 beaths per min or PaCO2 <4.3PKa
white blood cell count >12,000 cellsmm3
identify px at risk of sepsis
qSOFA - quick sequential organ failure assessment
- respiratory >=22breaths/min
- altered mentation [glasgow coma scale<15]
- systolic BP <=100mmHg
glasgow coma scale
assess level of consciousness or confusion
<15 for sepsis
aetiology of sepsis
infection triggers
gram-positive staph.aereus, gram negative, fungal candida
candida higher mortality compared to bacteria
who gets sepsis
aging population, medically and immune-compromised
cancer, cirrhosis, autoimmunity, HIV/AIDS, organ transplantation, diabetes
immunopathogenesis of sepsis
inflammatory disease
activation of innate immunity, complement system, vascular endothelium, coagulation system, adaptive immunity
pathophysiology of sepsis
body wide clotting, leaky vessels, one or more organs fail, persistent hypotension
PRRs
pattern recognition receptors
pattern associated molecular patterns
conserved exogenous factors expressed by pathogens
damage associated molecular patterns
endogenous host factors released following cell damage
cells which express PRR
macrophages and epithelial cells
triggers activation of inflammatory signalling pathways
innate immunity response to sepsis
cascade of chemokines, cytokines
TNFa stimulates expression of adhesion molecules and prtoeins which trigger blood clotting, recruitment of immune cells to site of infectionm prevent pathogen spreading via blood
contributes to onset of sepsis and septic shock - systemic vasodilation, increased vascular permeability, loss of BP, systemic blood clotting microvasculature
clotting = prevention of blood flow = organ failure = death
complement system hallmark of sepsis
amplification of systemic inflammation, recognition of PAMPs and DAMPs
peptides C3a C5a, immunopathogeneis, amplifies inflammation
vascular endothelium
changes, procoagulant state, loss of fluid and attachment of inflammatory cells, inflammatory mediators via blood, cells and proteins to leave, leaky vessels and blood clotting
coagulation system
interaction between coagulation and inflammation
hypercoagulative state - fibrin depostion, microvascular thrombi, neutrophil formation, endothelial injury
commonly affected organ systems
neurological [altered mental state]
pulmonary [hypoxaemia, ARDS]
cardiovascular [shock]
renal [oliguria]
excessive inflammation
sustained inflammation cause tissue injury, strong activation of innate immunity via PAMPs and DAMPs, sustained hyperinflammation, activation of complemenr, coagulation and vascular endothelium
immune suppression
innate and adaptive immunity, apoptosis of T cell Bcells, dysfunctional DCs, delayed apoptosis of dysfunctional neutrophuls, long term changes to immune function
treatment of sepsis
early administration of antibiotics within an hour
lung protective ventilation, vasopressors, external feeding, insulin therapy, urinary cathetar, fluids
dental abscess
immune response to acute bacterial infection of pulp space
contains immune cells, dead tissue, live bacteria
highly infectious
excision and drainage
periapical needs root canal/extraction
antibiotics ineffective unless widespread infection
can spread, leading to severe local and systemic consequences
