Sepsis

Question 1

Define sepsis

Answer 1

Life-threatening organ dysfunction due to a dysregulated host response to infection

Question 2

Which organisms commonly cause sepsis and why?

Answer 2

Though both gram (+) and (-) can, -ve is more common as it has LPS (e.g e.coli). LPS activates macrophages and NK cells which further amplify the immune response, producing positive feedback

Question 3

What are the 2 main pathophysiology pathways of sepsis?

Answer 3

Immune system and coagulation

Question 4

Describe the general overview of what happens once the immune system has been activated

Answer 4

1. TLR is activated and triggers a signalling cascade, recruiting adaptor proteins and activating transcription factors with NK kappa beta
2. activation of cytokines and mediators can cause a ‘cytokine storm’
3. leads to acute inflammation and stimulated adaptive immunity

Question 5

Describe 3 vascular and 1 cellular change that occurs during inflammation

Answer 5

Vascular: vasodilation, vascular permeability, increased adhesion of WBCs

Cellular: recruitment and activation of neutrophils

Question 6

What does NF kapa beta do?

Answer 6

Protein complex that controls the transcription of DNA and cytokine production

Question 7

What happens to the fluid volume and cardiovascular system following sepsis?

Answer 7

Absolute hypovolemia; more fluids going into the tissues to combat infection -> lowers the BP, triggering baroreceptors to initiate compensatory tachycardia

The increased vascular permeability and vasodilation also lowers the TPR/SVR

Question 8

What happens to the bloodflow to organs and why?

Answer 8

The reduced circulating volume reduces the venous return: so CO falls, BP falls more and the flow reduces to organs.

The activated coagulation pathway is also causing microthrombi to distribute throughout circulation

Question 9

What happens to the lungs as sepsis progresses?

Answer 9

Due to the difficulty of removing CO2 and circulating inflammatory mediators the patient will have tachypnoea and shortness of breath.

The surfactant dries out which may develop into acute resp distress syndrome

Question 10

What happens in acute resp distress syndrome?

Answer 10

Fluid leaks from blood vessels into alveoli so they become unstable and collapse - the amount of circulating O2 drops

Question 11

Why do patients experience sepsis become confused?

Answer 11

Not getting enough oxygen: As the body goes deeper into shock it protects the core and continually decreases supply to the brain

Not getting enough glucose:
Low O2 states increase insulin resistance so glucose cannot access the tissues or the brain.

Question 12

What happens to the pH in the tissues?

Answer 12

Anaerobic respiration increases so the pH falls, inducing metabolic acidosis

Question 13

Name 2 things you might see in the blood as a result of sepsis

Answer 13

1. Increased blood sugar; Low O2 increases insulin resistance and the body’s stress response (cortisol) promotes gluconeogenesis
2. CRP (a marker of inflammation)

Question 14

Describe the coagulation pathophysiology

Answer 14

Complement C5 splits into C5a and C5b. C5b activates MAC and C5a increases expression of TF on the surface of monocytes - initiating the coagulation cascade

Clots retrigger inflammation ad the immune response - positive feedback

Question 15

Why does purpura happen? How reliable of a sign is it?

Answer 15

The fibrin deposited in the blood vessels make bloodflow harder and accessive clots deplete the clotting factors and cause bleeding

Purpura is not a key recognition sign as it doesn’t always appear and can appear very late

Question 16

What acronym helps you recognize sepsis?

Answer 16

TIME:
Temperature (higher or lower than normal)
Infection 
Mental decline 
Extremely ill; severe pain or discomfort

Question 17

Name 5 red flags of sepsis

Answer 17

1. HR >130 bpm
2. Resp rate >25 per min
3. Not passed urine in last 18 hours
4. Lactate >2mmol/L
5. acute confusional state

Question 18

What is SIRS and what criteria define it?

Answer 18

SIRS is present if there are at least 2 of the following present (No longer the primary way to identify sepsis…)

1. Temp below 36 or above 38.3
2. HR >90
3. Abnormal resp rate and pCO2
4. Increase in WBC count
5. Confusion
6. Blood glucose >7mmol/L in non-diabetic patients

Question 19

What is the SOFA and the qSOFA score?

Answer 19

SOFA: suspected infection plus a change in 2 or more of the criteria involving resp, hematology (platelet count), liver (serum bilirubin), renal (serum creatinine or urine output), brain and cardiovascular (hypotension and vasopressor requirement)

qSOFA is a quick bedside way to assess:

1. resp rate of 22/min +
2. altered mentation (Glasgow coma scale less than 15)
3. systolic BP of 100 mmHg or less

Question 20

What topics are examined in the NEWs score and how is it scored/used?
POTSRL

Answer 20

Topics score max 3 for each
1. Respiration
2. systolic BP
3. Pulse rate
4. Oxygen saturation (if they require oxygen they score 2)
5. temperature
6. level of consciousness 
If the NEWS score reaches 5 use clinical judgement

Question 21

How would you manage sepsis?

Hint: The sepsis 6 bundle

Answer 21

Give…

1. IV antibiotics: initially broad to ensure the microorganism will respond
2. IV fluids
3. O2

Take…

1. Lactate levels
2. Blood culture; identify the presence of infection
3. Urine output measurement

Question 22

When and why would you give vasopressin?

Answer 22

Within 6 hours if the patient’s hypotension is not responding to the initial fluid rescucitation

Question 23

What type of antibiotic is doxycycline and how does it work?

Answer 23

Tetracycline

Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit

Question 24

Name 5 samples you might take in a patient presenting with symptoms alike to sepsis

Answer 24

1. Blood cultures – to see if a pathogen can be grown from her blood
2. Urea and Electrolytes – to determine her renal function
3. Liver Function Tests – determine her liver function
4. Coagulation screen (aPPT / PT) – to check clotting
5. Blood gas - to estimate Serum Lactate and acid /base balance

Question 25

What does a broad-spectrum antibiotic mean?

Answer 25

Covers gram (+), (-) and anaerobes

Question 26

List 2 places you might look at to find out more about which antibiotic to give

Answer 26

1. Microbiologist

2. Hospital antibiotic policy