Sepsis
LO: Define sepsis with reference to the sepsis-3 consensus statement
Sepsis
- Leading cause of critical illness and mortality worldwide
- Survivors often have long term physical and psychological deficits
- Some septic patients are bacteraemic
Sepsis-3
| Conceptualisation of sepsis | Identification of sepsis | Identification of septic shock |
|---|---|---|
| Dysregulated host response to infection - acute organ dysfunction | Infection plus life-threatening, infection related acute organ dysfunction | Sepsis plus hypoperfusion, identified by hypotension requriing vasopressor support |
LO: Describe the pathophysiology of sepsis
- Excessive inflammation
- More immune cells
- Metabolic changes
- Shift to glycolysis
- Mitochondrial dysfunction and reduced perfusion
- Make ATP faster and more glycolytic intermediates to act as substrate for respiratory burst and signalling molecules
- 'Warburg effect' - Glycolysis occurring as ATP made per time is greater but ATP yield is worse
Circulatory changes
- Macrovascular - impaired distribution of flow
- Microvascular - impaired distribution of flow and increased diffusion distances between capillaries and tissues
- Dilate arteriole to increase blood flow
- If all arterioles dilate the blood pressure will drop
Drop in arterial pressure
- Marker of severity of the infection and response there to
- Dilating arterioles will increase cardiac output but risks undermining control of how macrovascular blood flow is distributed
Microvascular changes
- Endothelial damage
- Loss of regulation of permeability
- Increased fluid movement from circulation to interstitium, impairing diffusion between tissues and capillaries
- Maldistributed capillary perfusion
- Consumptive coagulopathy
LO: Describe how sepsis can be recognised
Questions
- What is the evidence of infection?
- What is the source of the infection?
- How worried should we be?
LO: Interpret NEWS2 scores and state use and limitations of NEWS2 scores with respect to sepsis
NEWS2
- Designed to detect deterioration before high qSOFA/SOFA
- Not sepsis specific
LO: Explain the importance of identifying the source of sepsis with reference to both antimicrobial choice, duration and source control
Source
- Without source means broad spectrum antibiotics remain
- Greater toxicity to patient
- Antimicrobial resistance
- Harder without source to advise on duration
- Missed collection/biofilm so may not recover well with antibiotics alone