Sepsis Flashcards
Define sepsis
Defined as life threatening organ dysfunction caused by dysregulated host response to infection
SOFA score >2 can identify organ dysfunction consequent to infection and indicates overall mortality risk 10%
Describe SIRS
SIRS
- temp >38 or <36
- HR >90
- RR >20 or PaCO2 <32
- WBCs > 12,000 or <4000 or >10% bands
Describe the traditional model of sepsis
SIRS
Sepsis; SIRS + infection
Severe sepsis; sepsis + end organ damage
Septic shock; severe sepsis + hypotension
Describe qSOFA score
QUICK Sequential Organ Failure Assessment
- GCS < 15
- resp rate ≥ 22
- systolic bp ≤ 100
Define septic shock
A clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain MAP > 65mmHg and having a serum lactate of >2mmol/l despite adequate volume resus
Patients with septic shock have a hospital mortality of 40%
What are the sepsis 6?
TAKE 3 GIVE 3
- Administer Oxygen aim sats 94-98%
- Take blood cultures
- Give IV antibiotics
- Give IV fluids
- Check serial lactates
- Measure urinary output
Describe the pathophysiology of sepsis
Uncontrolled inflammatory response
Features consistent with immunosuppression
- loss of delayed hypersensitivity
- inability to clear infection
- predisposition to nosocomial infection
Name the three phases in the pathogenesis of sepsis
- Release of bacterial toxins
- Release of mediators
- Effects of specific excessive mediators
Describe the release of bacterial toxins in sepsis
Bacterial invasion into body tissues source of dangerous toxins
Might be neutralised by existing immune system
Commonly
- Gram -ve; lipopolysaccharide
- Gram +ve; Superantigens, microbial-associated molecular pattern
Describe the release of mediators in response to infection in sepsis
Effects of infections due to endotoxin release
Exotoxin release; pro-inflammatory response
Two types of mediators; Th1 or Th2
Describe the effects of specific excess mediators in sepsis
Pro-inflammatory mediators
- promote endothelial cell; leukocyte adhesion
- release of arachidonic acid metabolites
- complement activation
- vasodilation of blood vessels by NO
- increase coag by release of tissue factors and membrane coagulants
- cause hyperthermia
Anti-inflammatory mediators
- inhibit TNF-alpha
- augment acute phase reaction
- inhibit activation of coag system
- provide -ve feedback to pro-inflammatory mediators
Describe clinical features of sepsis
- Altered consciousness
- fever; chills, rigors, flushes, night sweats etc.
- confusion
- psychosis
- tachypnoea
- tachycardia
- hypothermia
- hypotension
- jaundive
- hepatomegaly
- oliguria
- anuria
Describe the possible effects of a host on sepsis presentation
Age Co-morbidities Immunosuppression - acquired; HIV/AIDS - drug induced; steroids, biologics - congenital Previous surgery i.e. splenectomy
Why take lactate measurement in sepsis?
Marker of generalised hypoperfusion i.e. severe sepsis
When to consider HDU referral in sepsis?
- low bp unresponsive to fluids
- lactate >2 despite fluid resus
- elevated creatinine
- oliguria
- liver dysfunction, bil, PT, plt
- bilateral infiltrates, hypoxaemia
