Infection session 2 - Lecture 1 - Acute Sepsis in ED

Question 1

What is sepsis?

Answer 1

• Life threatening organ dysfunction due to a dysregulated host response to infection. Represents acute physiological deterioration where the host’s immune system has over-reacted and started to compromise physiology of pt.
• Serious life threatening response to infection

Question 2

What is septic shock?

Answer 2

-Persisting hypotension requiring treatment to maintain BP despite fluid resuscitation

Question 3

What is bacteraemia?

Answer 3

-Presence of bacterial in the blood.

Question 4

How can you recognise sepsis? (general)

Answer 4

• Early Warning Score (3+)
• Clinical features suggesting source (pneumonia, UTI, meningitis)
• Check for red flags: high RR, low BP, high HR, unresponsible, fever, low I/O

Question 5

What is the sepsis 6 bundle?

Answer 5

• Take 3, give 3
• Oxygen
• Fluid challende
• Blood culture
• Lactate (arterial)
• IV ABX
• Measure urine output

Question 6

What urgent investigations can you do if you suspect sepsis?

Answer 6

• FBC, including urea (kidney function) and electrolyles
• PCR (blood)
• Blood sugar
• LFT (liver function test): sugar metabolism is disturbed in sepsis
• CRP: marker of inflammation
• Coagulation studies
• Blood gas: lactate levels, CO2 and O2 levels
• Other microbiology samples: CSF, urine, swabs

Question 7

What bacteria commonly causes meningitis? What do you know about it?

Answer 7

• Neisseria meningitidis (often referred to as meningococcus)
• Spread via direct contact with respiratory secretions (most ppl are harmlessly colonised)
• Gram neg
• Causes meningitis (form of sepsis)
• Diplococcus, outer membrane acts as an endotoxin
• Numerous sero-groups: A B C, W

Question 8

Why are endotoxins important?

Answer 8

-Toxin (released by bacteria) into cells that have the ability to provoke an intense inflammatory response.

Question 9

Describe the inflammatory cascade

Answer 9

• Endo-toxin binds to macrophages ==> local response
• Local response: cytokines are released (TNF, IL1) ==> systemic response
• Systemic response: cytokines are released into circulation, stimulation of growth factor, macrophages and platelets (goal is to control infection)
• Cytokines lead to ==> Sepsis
• Sepsis: cytokines lead to activation of humoral response, get circulatory insult (DIC [disseminated intravascular coagulation] and injury) and perfusion to vital organs is diminished.

Question 10

What is the relationship between sepsis and coagulation?

Answer 10

• cytokines initiate production of thrombin: promotes coag.
• cytokines inhibit fibrinolysis
• coag. cascade leads to microvascular thrombosis (main cause of shock/multi-organ failure) –> organ ischaemia, DIC, dysfunction and failure

Question 11

What is a non blanching purpuric rash?

Answer 11

Red spots on skin that don’t go away when pressed. Can be (but not always) a sign of infection).

Question 12

What type of supportive treatment should you give to somebody with sepsis?

Answer 12

• Symptom relief

- physiological restoration: sepsis 6, regular monitoring and assessment, consider early referral to ITU

Question 13

What is empiric choice of ABC for meningitis?

Answer 13

-Ceftriaxone

Question 14

Name a few life threatening complications of meningitis and (by extension) the sepsis that ensues

Answer 14

• Irreversible hypo tension –> poor organ perfusion, loss of limbs (ischaemic necrosis of digits/hands/feet)
• Resp failure
• Acute kidney injury/failure (one of 1st organs affected)
• Raised intracranial pressure

Question 15

What preventative measures are there against meningitis population wise and on a more individual basis?

Answer 15

• Vaccination: C, ACWY, Sero group B (very new)

- ABX prophylaxis: notifiable disease, must be reported to public health England, vaccinate/ABX close contacts