Sepsis Flashcards
Define infection
Invasion and multiplication of pathogenic microbes in an area of the body where they are not normally present- leads to disease
Define systemic inflammatory response syndrome
Inflammatory response to infection that affects the whole body
Define sepsis
When the body’s own response to infection causes injury to its own tissues and organs. Must have systemic inflammatory response syndrome plus known or suspected infection
Give 3 common reasons for SIRS
Pancreatitis (inflammation)
Infection
Burns
Trauma
In original definition of systemic inflammatory response syndrome (1991):
What are the criteria?
How many criteria have to be fulfilled to have SIRS?
Need to have more than 2 of (at least two of):
1) temperature above 38 or below 36 degrees Celsius
2) respiratory rate above 20 breaths per min
3) heart rate of more than 90 bpm
4) partial pressure of CO2 less than 32 mmHg
5) White blood cell count: more than 12,000/ uL or less than 4000/uL or more than 10% immature WBC’s
Define severe sepsis
Sepsis (Systemic inflammatory response syndrome + known/suspected infection) PLUS severe organ dysfunction -includes septic shock
Define septic shock
Septic shock occurs when there is sepsis plus the inability to maintain blood pressure- HYPOTENSION.
This is accompanied by signs of hypoperfusion-
1) decreased urine output
2) high serum lactate (anaerobic respiration)
3) decreased consciousness on GCS
How does mortality change with the sepsis severity?
Uncomplicated sepsis- 10% mortality
Severe sepsis- 35%
Septic shock- mortality 50 %
What key 4 pathological features occurs in sepsis? (After activating innate/adaptive immune response)
1) hypovolaemia
2) hypotension
3) hypoxaemia
4) hypoperfusion
Describe the pathogenesis of sepsis
- Recognition of PAMP’s by pattern recognition receptors
- Activation of coagulation cascade leading to microclots, and activation of complement pw
- Release of proinflammatory cytokines - increased vasculature permeability and vasodilation
- Increase in neutrophil number and activation, diapedesis, increase in EC killing, tissue and vasculature damage- plasma leakage into tissues
- Pulmonary oedema acute respiratory distress- hypoxemia
- Prolonged vasodilation —> hypotension
- Increased vasc. Permeability —-> hypovolaemia
- Hypovolaemia and hypotension —-> hypoperfusion
- Hypoperfusion—-> organ ischameia—-> multiorgan failure:
Kidneys
Bowels
Liver function- drop in blood glucose levels, decreased cellular metabolism
What is the updated 2001 SIRS criteria?
Temperature above 38 or below 36
Heart rate > 90 bpm
Respiratory rate > 20/min or pCO2 < 32mmHg
White blood cells : WCC> 12,000/ uL or WCC< 4000/uL or 10% immature WCC
Blood Glucose > 7.7 mol /L WITHOUT DIABETES
Decreased conscious level
When is severe sepsis suspected?
When any RED FLAG feature is present
What are the red flag features of severe sepsis?
Even if lacking any other sign of sepsis:
1) HR> 130 bpm
2) RR > 25/ min
3) BP < 90 mmHg or MABP < 65mmHg
4) purpuric rash with negative glass test
5) oxygen saturation < 91%
6) serum lactate > 2 mmol/L
7) decreased conciousness on GCS
What is a fast bedside assessment of sepsis?
Quick SOFA: quick sepsis related organ failure assessment
Requires : respiratory rate above 22, altered cognition, systolic BP below 100 mmHg
Give some examples of infections that can cause sepsis
1) CNS - meningitis, encephalitis
2) respiratory - pneumonia
3) heart- infective endocarditis
4) urinary- UTI and pyelonephritis
5) skin - necrotising fasciitis and cellulitis
6) joints and bone- osteomyelitis and septic arthritis
7) malaria
8) GI- gastroenteritis
