Infection 5 - Acute Sepsis

Question 1

Define “Sepsis”

Define “Septic shock”

Answer 1

• Sepsis is characterised by a life-threatening infection due to a dysregulated host response to an infection
• Septic shock is a subset of sepsis where particularly profound circulatory, cellular + metabolic abnormalities substantially increase mortality.

Question 2

Describe the pathophysiology of an infection that results in sepsis?

Answer 2

• Pathogen breaches innate barriers leading to inflammation (vasodilation, capillary leakage + amplification of immune system)
• Initially this inflammation is local, in the vicinity of pathogens
• Sepsis occurs when this inflammatory process becomes overwhelming and occurs throughout the body.

Question 3

By what mechanisms do micro-organisms trigger inflammatory reactions?

Answer 3

• Gaining entry into the host (e.g. via respiratory, GI, urogenital, skin)
• Adherence to host cells (e.g. via cell surface adhesion molecules,
  fimbriae/pili)
• Invasion into host cells / mucosal surfaces (e.g. via enzymes such as collagenase and hyaluronidase)

Question 4

What are the observations seen with sepsis + the reasons they occur?

Answer 4

1) HR rises - (BP = SV x TPR x HR - leaky capillaries reduced circulating volume and therefore preload and SV, vasodilation decreases TPR. HR rises in order to compensate and maintain BP)

2) RR rises - in order to maintain blood pH
3) Urine output drops - to conserve circulating volume
4) BP drops - HR no longer able to compensate for decreased TPR + SV (called decompensation) - if not treated quickly, hypoxia can cause cell death.

Question 5

Who is at particular risk of developing sepsis?

Answer 5

• Very young (< 1 year)
• Elderly ( > 75 years)
• Pregnant + post-partum
• Immunocompromised individuals

Question 6

How is sepsis diagnosed?

Answer 6

• Initially NEWS - uses measurements such as RR, SPO2, BP, Pulse, Temp etc to give a generalised idea of how sick the patient is.
• QSOFA - respiratory rate of 22/min or more, altered mental state + systolic BP of 100 or less (2 out of 3 = higher mortality)
• Red-flag sepsis - If one box ticked in yellow, and one ticked in orange, look for 1 red flag. If 1 red flag, start treatment immediately.

Question 7

What is the sepsis six bundle used to treat sepsis?

Answer 7

• Start sepsis 6 within 1st hour (golden hour)
• Remember “Give 3, Take 3”

Give - Oxygen, Antibiotics + Fluids
Take - Cultures, HB/Lactate + Monitor Urine