Acute Sepsis in the ED

Question 0

Understand the principles of Systemic Inflammatory Response Syndrome (SIRS)

Answer 0

An inflammatory state affecting the whole body, a response to a non-specific insult e.g. trauma, ischaemia, infection
Two or more clinical features of sepsis

Question 1

Understand the clinical features of acute sepsis

Answer 1

Temperature: 38
Heart rate: >90bpm
Respiratory rate: >20/min
WBC: 12x10^9

Question 2

Understand the mechanism by which microorganisms trigger the inflammatory cascade

Answer 2

Endotoxins bind to macrophages –> local cytokines –> systemic cytokines –> homeostasis not restored (SIRS)

Question 3

What is sepsis?

Answer 3

SIRS + documented infection

Question 4

What is septicaemia?

Answer 4

Generalised sepsis

Question 5

What is bacteraemia?

Answer 5

Presence of bacteria in the blood

Question 6

What is severe sepsis?

Answer 6

SIRS + organ dysfunction/hypoperfusion

Question 7

What is septic shock?

Answer 7

Severe sepsis + persistently low BP despite IV fluid administration

Question 8

Understand the principles of treatment for acute sepsis

Answer 8

High flow oxygen, take blood and other cultures, give IV fluid and IV antibiotics, measure urine output and serum lactate

Question 9

Describe features of Neisseria meningitidis and of meningococcal disease

Answer 9

Neisseria meningitidis - G-ve diplococci, prevents phagocytosis (evades immune response), main cause of bacterial meningitis in children and young adults, spread by exchange of saliva and other respiratory symptoms
Meningococcal disease - vaccine, spread by aerosols, nasopharyngeal secretions, treat with cephalosporins

Question 10

Describe the important barriers to infection

Answer 10

Physical - skin, mucous membranes, nostril hairs, bronchial cilia
Physiological - vomiting, sneezing, coughing, diarrhoea
Chemical - low pH, antimicrobial molecules (IgA, lysosome)
Biological - normal flora compete with pathogens, produce antimicrobial chemicals and synthesis vitamins (e.g. K, B12)

Question 11

Describe the components of the innate immune system

Answer 11

Neutrophils, monocytes, macrophages, dendritic cells, NK cells, eosinophils, mast cells
Complement system
Pathogen associated molecular patterns (PAMPs)
Pathogen recognition receptors (PRRs)
Opsonisation of microbes
Engulfment
Degradation
Oxygen dependent pathway (respiratory burst)