Session 3 - Sepsis Flashcards Preview

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Flashcards in Session 3 - Sepsis Deck (39)
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1
Q

What is the overall infection model?

A

• Pathogen + Patient + Mechanism of infection –> Infection –> Management –> Outcome

2
Q

What factors about a person do we take into account when they present acutely unwell

A
• Person
	○ Age
	○ Gender
	○ Physiological state
	○ Pathological state
	○ Social factors
• Time
	○ Calendar time
	○ Relative time
• Place 
	○ Current 
Recent
3
Q

What are the symptoms of acute sepsis?

A
  • Pale, cool extremities
  • High temperature
  • High pulse
  • Low BP
  • Widespread non-blanching rash
  • Neck stiffness
4
Q

Outline the clinical features of sepsis

A
• Systemic inflammatory response syndrome
• A response to a non-specific insult
• Two or more of 
	○ Temperatures 38*
	○ Heart rate >90/min
	○ Respiratory rate 20/min
	○ WBC 12 x 10*9
5
Q

What is a purpuric rash?

A

• Problem with microvasculature beneath the skin, causing rash like bruises

6
Q

What is the glass tumbler test?

A

• Glass pressed against rash, if it does not blanche it is purpuric

7
Q

What is bacteraemia?

A
  • Presence of bacteria in the blood

* Strictly microbiological

8
Q

What is septicaemia?

A

• Clinical term describing generalised sepsis

9
Q

What can sepsis be defined as?

A
  • Systemic response to infection

* Systemic inflammatory response syndrome plus documented or presumed infection

10
Q

What is severe sepsis defined as?

A

• SIRS + organ dysfunction or organ hypoperfusion

11
Q

What is septic shock?

A

• Severe sepsis plus persistently low BP despite administration of fluids

12
Q

What is the cause of SIRs?

A

• A non specific insult
○ Ischaemia
○ Trauma
Infection

13
Q

What is sepsis?

A

• SIRs with an identified or hypothesised source of infection

14
Q

Outline what occurs after initial infection

A
  • Attachment –> Toxin production –> damage

* Attachment –> interaction with host defences –> inflammation –> host damage

15
Q

Outline the inflammatory cascade in sepsis

A

• Endotoxin -> cytokines -> Cytokines released into circulation

16
Q

How is neisseria meningitidis spread?

A

• Direct contact with respiratory secretions (droplet infection)

17
Q

What does the pilus of a bacteria do?

A

Enhances attachmen

18
Q

What does a polysaccharide capsule of a bacteria do?

A
  • Promotes adhernece

* Prevents phagocytosis

19
Q

What does an endotoxin of neisseria meningitidis do?

A

Triggers inflammation

20
Q

What is meant by an “endotoxin”

A

• Intrinsic part of cell wall, released when bacteria break down

21
Q

Outline the inflammatory cascade

A

• Endotoxin – Cytokines (TNF, interleukins) –> Cytokines released into circulation –> Homeostasis not restored

22
Q

What are the normal functions of cytokines? (3)

A
  • Stimulate inflammatory response to promote wound repair and recruit RE system
  • Stimulating growth factor for macrophages and platelets
  • Lead to activation of humoral cascade and RE system
23
Q

How do cytokines cause organ failure? (6)

A

• initiate production of thrombin and thus promote coagulation
• Inhibits fibrinolysis
• Coagulation cascade leads to microvascular thrombosis and hence
• Organ ischaemia, dysfunction and failure
• Microvascular injury is the major cause of shock and multiorgan failure
Causes Disseminated Intravascular Coagulation

24
Q

Give three other urgent investigations for sepsis

A
Full blood count, Urea and Electrolytes
• EDTA bottle for PCR
• Blood sugar
• Liver Function Tests
• C-Reactive protein (CRP)
• Clotting studies
• Blood gases
25
Q

What are the two key treatments for sepsis?

A
• Specific
	○ Antimicrobials
        - Surgery 
               - Draiange, debridement, dead space removal 
• Support
        - Physiological restoration
26
Q

Outline the sepsis 6 general treatments

A
    1. Deliver high flow oxygen
    1. Take blood cultures and other cultures, consider source control
    1. Administer empirical IV antibiotics
    1. Measure serum lactate
    1. Start IV fluid resuscitation
    1. Commence accurate urine output measurement
27
Q

What two factors need to be taken into account when choosing anti-biotic treatment

A

• Active against likely pathogens
• Agent that penetrates into the CSF
- Cefttriaxone

28
Q

Give five life threatening complications of meningitis

A
  • Irreversible hypotension
  • Respiratory failure
  • Acute kidney injury (renal failure)
  • Raised intracranial pressure
  • Ischaemic necrosis of digits/hands/feet
29
Q

Give three ways to confirm diagnosis of meningitis

A
• Blood culture
• PCR of blood
• Lumbar puncture
	○ Culture of cerebrospinal fluid
	○ PCR of cerebrospinal fluid
30
Q

What is looked for in cerebro spinal fluid?

A
  • Appearance, turbidity and colour
  • Microscopy WBCs, RBCs
  • Gram stain
31
Q

What gram stain would you receive from Neisseria meningitidis

A

• Gram-negative diplococcus

32
Q

How does Neisseria menigitidis stay under cover?

A

• Evade immune response with polysaccharide capsular antigen

33
Q

What vaccinations for meningitis are available?

A
  • Serogroup C vaccinated for

* Seogroup B not yet in routine use

34
Q

Why is it difficult to vaccinate against serogroup B?

A

• B capsule poorly immunogenic and similar to neural tissue

35
Q

What are the 2 ways in which meningitis can be prevented?

A
  • Antibiotic prophylaxis

* Vaccination

36
Q

What happens if meningitis is detected?

A

• Cases reported to the local health protection unit of public health England.
- Close contacts can be given antibiotic prophylaxis and considered for vaccination

37
Q

What are the three factors which give us a diagnosis in a clinical setting?

A

History
Examination
Investigation

38
Q

Give two main factors indicative of organ hypoperfusion

A

Hypotension

Decreased urine output

39
Q

Is neisseria meningitidis a rare organism?

A

No, 25% of young adults are carriers