Sepsis Flashcards

1
Q

what is sepsis?

A

life threatening organ dysfunction due to a dysregulated host response to infection

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2
Q

what is a SOFA score?

A

score which assesses the risk of organ failure in patients

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3
Q

what are the signs and symptoms of systemic inflammatory response syndrome? (SIRS)

A

patients experiencing two of the following symptoms:

  • body temperature > 38°C or < 36°C
  • rapid heart rate (>90 beats per minute)
  • rapid respiratory rate (>20 breaths per minute or arterial CO2 <32mmHg)
  • high white blood cell count ( >12x10^9l)
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4
Q

what are the signs and symptoms of sepsis?

A

systemic inflammatory response syndrome and proven or suspected infection

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5
Q

what would classify as severe sepsis?

A

sepsis and acute organ dysfunction

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6
Q

signs and symptoms of a patient suffering from septic shock?

A

sepsis and persistent hypotension after fluid resuscitation

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7
Q

what is a tool that helps to characterise patients at risk of sepsis/

A

qSOFA

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8
Q

what is the baseline qSOFA?

A

0 (unless patient has pre-existing organ dysfunction before onset of infection)

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9
Q

what is the most common cause of sepsis?

A

bacterial infection

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10
Q

examples of conditions that may make patients more at risk of developing sepsis?

A
  • cancer
  • cirrhosis
  • autoimmunity
  • HIV/AIDS
  • organ transplantation
  • diabetes
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11
Q

what is the immunopathogenesis of sepsis associated with?

A

activation of:

  • innate immunity
  • complement system
  • vascular endothelium
  • coagulation system
  • adaptive immunity
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12
Q

what is the pathophysiology of sepsis?

A
  • body wide blood clotting and ‘leaky vessels’
  • one or more organs begins to fail
  • persistent hypotension
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13
Q

what are pattern recognition receptors? (PRRs)

A

receptors expressed by the host (on host cells, innate immune cells, endothelial cells, fibroblasts) which recognise:

  • PAMPs
  • DAMPs
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14
Q

what are PAMPs?

A
conserved exogenous (non-self) factors expressed by pathogens
- molecules expressed by pathogens
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15
Q

what are DAMPs?

A

endogenous (host) factors released following cell damage

  • nucleic acid
  • heat shock proteins
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16
Q

if PRRs are activated (by PAMPs or DAMPs) what occurs?

A

activation of inflammatory signalling pathways

17
Q

what are Toll-like receptors?

A

they are pattern recognition receptors (PRRs) which play a crucial role in the activation of the innate immune response

18
Q

what is TNFalpha?

A

a master regulator cytokine

19
Q

what is the function of TNFalpha? how can this affect sepsis?

A

it co-ordinates local containment of infection but drives sepsis when released systemically

20
Q

how does TNFalpha control local infections?

A

TNFa stimulates expression of:
- adhesion molecules on endothelial cells
- proteins that trigger blood clotting
TNFa also recruits immune cells to site of infection and prevents pathogen spreading via blood

21
Q

what does the systemic release of TNFa contribute to?

A

onset of sepsis and septic shock by:

  • systemic vasodilation
  • increased vascular permeability
  • loss of blood pressure
  • systemic blood clotting of microvasculature
22
Q

how does activation of the complement system drive sepsis?

A
  • complement pathway is activated immediately upon recognition of PAMPs and DAMPs
  • this causes generation of peptides C3a and C5a (extremely inflammatory)
  • C5a drives immunopathogenesis of sepsis as it is a potent chemoattractant (for macrophages, neutrophils and monocytes)
  • this further amplifies inflammation by contributing to vasodilation, tissue damage and organ failure
23
Q

what changes occur in the vascular endothelium in response to inflammatory stimuli during sepsis?

A
  • endothelium is converted to a pro-coagulant state
  • the disrupted endothelium mediates loss of fluid & also facilitates the recruitment, attachment and extravasion of INFLAMMATORY CELLS through the endothelium
24
Q

what effect does sepsis have on the coagulation system?

A

sepsis results in a hypercoagulative state, characterised by:

  • microvascular thrombi
  • fibrin deposition
  • neutrophil extracellular trap formation
  • endothelial injury
25
Q

how does sepsis initiate the coagulation cascade?

A

DAMPs, microbes, complement activations and release of inflammatory cytokines on mediators can initiate the coagulation cascade (widespread)

  • some areas of body experience excessive bleeding
  • some areas of body experience clotting
26
Q

what organ systems does sepsis commonly affect? how does this present in a patient?

A
  • neurological = lethargy, confusion, delirium
  • pulmonary (hypoxaemia) = acute respiratory distress syndrome (ARDs)
  • cardiovascular (shock)
  • renal (oligouria)
27
Q

what is hypoxaemia?

A

reduced oxygen level in blood (reduced oxygen reaching organs)

28
Q

how does ARDs present?

A

lungs fill with inflammatory infiltrate & fluid (patients cannot get enough oxygen into blood)

29
Q

how does sepsis affect the adaptive immune response?

A

sepsis causes apoptosis of T cells and B cells

30
Q

how would a sepsis patient be treated?

A
  • antibiotics (early administration)
  • vasopressors (1-6 hours after onset)
  • enteral feeding
  • insulin therapy
  • fluids
  • lung protective ventilation
  • urinary catheter
31
Q

what is the function of vasopressors? examples that may be given to a sepsis patient?

A

vasopressors cause vasoconstriction of blood vessels in order to increase blood pressure

  • norepinephrine
  • epinephrine
  • vasopressin
32
Q

what are examples of fluids that may be given to a sepsis patient?

A
  • colloids

- crystalloid

33
Q

what are dental abscesses?

A

a (highly infectious) buildup of pus that develops during immune response to acute bacterial infection of the pulp space

34
Q

what may be found within a dental abscess?

A

immune cells, dead tissue and LIVE bacteria

35
Q

how would a dental abscess be treated?

A
  • excision and drainage

- RCT or extraction for periapical abscesses

36
Q

what are some red flag signs and symptoms of spreading dental infection?

A
  • temp <36 or >38
  • elevated breathing rate (>20 breaths/min)
  • elevated or reduced HR
  • facial swelling
  • trismus
  • dehydration