Session 3 - Sepsis Flashcards
What is the overall infection model?
• Pathogen + Patient + Mechanism of infection –> Infection –> Management –> Outcome
What factors about a person do we take into account when they present acutely unwell
• Person ○ Age ○ Gender ○ Physiological state ○ Pathological state ○ Social factors • Time ○ Calendar time ○ Relative time • Place ○ Current Recent
What are the symptoms of acute sepsis?
- Pale, cool extremities
- High temperature
- High pulse
- Low BP
- Widespread non-blanching rash
- Neck stiffness
Outline the clinical features of sepsis
• 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
What is a purpuric rash?
• Problem with microvasculature beneath the skin, causing rash like bruises
What is the glass tumbler test?
• Glass pressed against rash, if it does not blanche it is purpuric
What is bacteraemia?
- Presence of bacteria in the blood
* Strictly microbiological
What is septicaemia?
• Clinical term describing generalised sepsis
What can sepsis be defined as?
- Systemic response to infection
* Systemic inflammatory response syndrome plus documented or presumed infection
What is severe sepsis defined as?
• SIRS + organ dysfunction or organ hypoperfusion
What is septic shock?
• Severe sepsis plus persistently low BP despite administration of fluids
What is the cause of SIRs?
• A non specific insult
○ Ischaemia
○ Trauma
Infection
What is sepsis?
• SIRs with an identified or hypothesised source of infection
Outline what occurs after initial infection
- Attachment –> Toxin production –> damage
* Attachment –> interaction with host defences –> inflammation –> host damage
Outline the inflammatory cascade in sepsis
• Endotoxin -> cytokines -> Cytokines released into circulation
How is neisseria meningitidis spread?
• Direct contact with respiratory secretions (droplet infection)
What does the pilus of a bacteria do?
Enhances attachmen
What does a polysaccharide capsule of a bacteria do?
- Promotes adhernece
* Prevents phagocytosis
What does an endotoxin of neisseria meningitidis do?
Triggers inflammation
What is meant by an “endotoxin”
• Intrinsic part of cell wall, released when bacteria break down
Outline the inflammatory cascade
• Endotoxin – Cytokines (TNF, interleukins) –> Cytokines released into circulation –> Homeostasis not restored
What are the normal functions of cytokines? (3)
- 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
How do cytokines cause organ failure? (6)
• 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
Give three other urgent investigations for sepsis
Full blood count, Urea and Electrolytes • EDTA bottle for PCR • Blood sugar • Liver Function Tests • C-Reactive protein (CRP) • Clotting studies • Blood gases
