Sepsis and Septic Shock

Question 1

What is sepsis?

Answer 1

Systemic illness caused by microbial invasion of normally sterile parts of the body

Question 2

What is SIRS?

Answer 2

Systemic inflammatory response syndrome

Question 3

What does the traditional model of sepsis show?

Answer 3

The relationship of infection and SIRS in causing sepsis

Question 4

What is the definition of sepsis?

Answer 4

Life threatening organ dysfunction caused by dysregulated host response to infection

Question 5

How can organ dysfunction be identified?

Answer 5

An acute change in total SOFA score > 2

Question 6

How can septic shock be identified?

Answer 6

A clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain MAP (>65mmHg) and a serum lactate of >2mmol/l despite adequate volume resuscitation

Question 7

Which components make up the SOFA score of Sepsis-3?

Answer 7

PaO2/FiO2, platelets, bilirubin, MAP, GCS, creatinine and urine output

Question 8

What are the components of qSOFA and what does it mean?

Answer 8

• Hypotension: systolic BP <100 mmHg
• Altered mental state
• RR > 22
• Score > 2 suggests a greater risk of a poor outcome (long ICU stay or death)

Question 9

Describe the pathophysiology of sepsis

Answer 9

• Uncontrolled inflamm. response
• Features of immunosuppression: loss of delayed hypersensitivity, inability to clear infection and predisposition to nosocomial infection
• Initial increase in inflamm. mediators
• Shift toward an anti-inflammatory immunosuppressive phase

Question 10

Which bacterial toxins are commonly released?

Answer 10

• Gram negative: lipopolysaccharide (LPS)
• Gram positive: microbial -associated molecular pattern (Lipoteichoic acid and Muramyl dipeptides)
• Super-antigens: staphylococcal toxic shock syndrome toxin and streptococcal exotoxins

Question 11

Describe the mediator role in sepsis

Answer 11

• TH1 vs TH2
• Pro-inflamm mediators: cause inflamm. response that characterises sepsis
• Compensatory anti-inflamm response: can cause immunoparalysis

Question 12

What is the effect of excessive pro-inflammatory mediators?

Answer 12

• Promote endothelial cell-leukocyte adhesion
• Release of arachidonic acid metabolites
• Complement activation
• Vasodilatation of blood vessels by NO
• Increase coagulation by release of tissue factors and membrane coagulants
• Cause hyperthermia

Question 13

What is the effect of excessive anti-inflammatory mediators?

Answer 13

• Inhibit TNF alpha
• Augment acute phase reaction
• Inhibit activation of coagulation system
• Provide negative feedback mechanisms to pro-inflamm mediators

Question 14

What are the clinical features of organ dysfunction (and therefore sepsis)?

Answer 14

• Altered consciousness, confusion and psychosis
• Tachypnoea, PaO2 < 70mmHg and sats <90%
• Decreases platelets and protein C
• Increased PT/APTT and D-dimer
• Tachycardia and hypotension
• Oliguria, anuria and increased creatinine

Question 15

What are the general features of sepsis?

Answer 15

• Fever: chills, rigors, flushes, cold sweats, night sweats etc.
• Hypothermia (esp. elderly, young children and immunosuppressed)
• Altered mental state
• Hyperglycaemia in the absence of diabetes

Question 16

What would you expect the inflammatory variables to be in sepsis?

Answer 16

• Leucocytosis (WWC> 12,000/ml) or leucopenia (WCC < 4,000/ml)
• Normal WCC with greater than 10% immature forms
• High CRP
• High procalcitonin

Question 17

What would you expect the haemodynamic variables to be in sepsis?

Answer 17

• BP: Systolic <90mmHg or MAP <70mmHg

- SvO2 > 70%

Question 18

Which organ dysfunction variables would you expect to see in sepsis?

Answer 18

• Arterial hypoxaemia (PaO2/FiO2 < 50mmHg)
• Oliguria (<0.5 ml/kg/hr)
• Increased creatinine
• Coagulation abnormalities (PT > 1.5 or APTT > 60s)
• Ileus
• Thrombocytopenia
• Hyperbilirubinaemia

Question 19

Which tissue perfusion variables might you see in sepsis?

Answer 19

• High lactate

- Skin mottling and reduced capillary perfusion

Question 20

Which host factors may effect the sepsis presentation?

Answer 20

• Age
• Co-morbidities
• Immunosuppression (acquired, drug induced and congenital)
• Splenectomy

Question 21

Which organism factors will effect the presentation of sepsis?

Answer 21

• Gram positive vs negative
• Virulence factors (MRSA, toxin secretion, ESBL etc.)
• Bioburden

Question 22

What are the components of the Sepsis 6?

Answer 22

• Blood cultures
• Blood lactate
• Measure urine output (catheter if severe sepsis or septic shock)
• Oxygen sats (aim for 94-98%)
• IV antibiotics
• IV fluid challenge (crystalloid bollus)

Question 23

When should a referral to HDU be considered?

Answer 23

• BP low and responsive (?) to fluids
• Lactate > 2 despite fluid resuscitation
• Elevated creatinine
• Oliguria
• Liver dysfunction
• Bilateral infiltrates and hypoxaemia

Question 24

When should a referral to ITU be considered?

Answer 24

• Septic shock
• Multi-organ failure
• Requirement for sedation, intubation and ventilation