Sepsis and Septic Shock Flashcards
Definition of sepsis
A systemic illness caused by microbial invasion of normally sterile parts of the body and a dysregulated host response to the infection
What does SIRS stand for?
Systemic inflammatory response syndrome
SIRS is when there is 2 or more of….
Temp > 38 or < 36
HR > 90
RR > 20 or PaCO2 < 32
WBCs > 12000 or <4000 or > 10% Ioand
Sepsis is a combination of…
SIRS and infection
Severe sepsis is a combination of….
Sepsis and end organ damage
Septic shock is a combination of….
Severe sepsis and hypotension
If have SIRS, does it always mean that there is an infection?
No
Definition of organ dysfunction due to sepsis
An acute change in total SOFA score > 2 points consequent to the infection
Definition of severe sepsis
Sepsis-induced tissue Hypoperfusion or organ dysfunction (any of the following through to be due to the infection)
qSOFA variables
Respiratory rate (>22/min tachypnoea) Mental status altered Systolic BP (<100mmHg)
SOFA variables
PaO2/FiO2 ratio GCS Mean arterial pressure (MAP) Administration of vasopressors by type and dose rate of infusion Serum creatinine or urine output Bilirubin Platelet count
What is qSOFA for?
Patients with suspected infection who are likely to have prolonged ICU stay or die in the hospital can be promptly identified with qSOFA
What score of qSOFA suggests a greater risk of a poor outcome
2 or more
What can survival in septic shock be based on?
Antimicrobial delay
3Rs of sepsis kills
Recognise
Resuscitate
Refer
Body’s defence against sepsis
Physical barrier - skin - mucosa - epithelial lining Innate immune system - IgA in GI tract - dendritic cells/macrophages Adaptive immune system - lymphocytes - immunoglobulins
Pathology of sepsis
Uncontrolled inflammatory response
Patients with sepsis have features consistent with immunosuppression
- loss of delay hypersensitivity
- inability to clear infection
- predisposition to nosocomial infection
Probable changes of sepsis syndrome over time
- initially an increase in inflammatory mediators
- later a shift towards an anti-inflammatory immunosuppressive phase
- Depends on health of patient
3 stages in the pathogenesis of sepsis
- release of bacterial toxins
- release of mediators
- effects of specific excessive mediators
Commonly released toxins in sepsis
Gram -ve
- lipopolysaccharide (LPS)
Gram +ve
- microbial assisted molecular pattern (MAMP) - lipoteichoic acid
- superantigens - staphylococcal toxic shock syndrome toxin (TSST)
Effects of release of mediators in sepsis
Effects of infections due to endotoxin release (LPS)
Effects of infections due to exotoxin release (pro-inflammatory response and small amounts of super antigens will cause large amounts of mediators to be released -> cascade effects)
Mediator role on sepsis
- Th1 vs Th2
What does Th1 mediator do?
Pro-inflammatory mediator - causes inflammatory response that characterises sepsis
What does Th2 mediator do?
Compensatory anti-inflammatory reaction - can cause immunoparalysis
Release of mediators in sepsis can lead to either;
apoptosis
an inflammatory reaction
What are the effects of pro-inflammatory mediators?
Promote endothelial cell leukocyte adhesion
Release of arachidonic acid metabolites
Complement activation
Vasodilation of blood vessels by NO
Increase coagulation by release of tissue factors and membrane coagulants
Causes hyperthermia
What are the effects of anti-inflammatory mediators?
Inhibit TNF alpha
Augment acute phase reaction
Inhibit activation of coagulation system
Provide negative feedback mechanisms to pro-inflammatory mediators
If pro-inflammatory > compensatory anti-inflammatory, results in…
Septic shock with multiorgan failure and death
If Compensatory anti-inflammatory > pro-inflammatory results in….
Immunoparalysis with uncontrolled infection and multi organ failure
Clinical presentation of sepsis depends on….
Host
organism
environment
Presentation of sepsis (general)
fever > 38C (chills, rigor, flushes, cold sweats etc)
Hypothermia < 36C (elderly and very young children esp)
HR > 90 tachycardia
Tachypnoea >20/min
Altered mental status (esp. elderly)
Hyperglycaemia >8mmol/L in absence of diabetes
Organ dysfunction features of sepsis
Altered consciousness, confusion and psychosis Tachypnoea (PaO2 < 70, stats <90%) Jaundice - increase liver enzymes - decreased albumin - increased PT Tachycardia and hypotension Oliguria, anuria and increased creatinine Blood - decreased platelets - increased PT/APTT - decreased Protein C - Increased D-dimer
Inflammatory variables in sepsis
Leucocytosis (WCC > 12000) Leucopenia (WCC < 4000) Normal WCC with > 10% immature forms High CRP High prolactonin
Haemodynamic variables in sepsis
Arterial hypotension (systolic <90 or MAP < 70) SvO2 > 70%
Tissue perfusion variables in sepsis
High lactate
Skin mottling and reduced capillary perfusion
Effects of host on sepsis presentation
Age Co-morbidities - COPD - DM - CCF - CRF - Disseminated malignancy Immunosuppression - Acquired (HIV/AIDs) - Drug induced (steroids, chemo, biologics) - congenital (phagocytic defects etc) Previous surgery - splenectomy
Effect of organism on presentation of sepsis
Gram +ve more likely up
Gram -ve more likely down
Virulence factors e.g. MRSA, toxin secretion
Bioburden
Effect of environment on presentation of sepsis
occupation
travel (esp. if present with chest infection or gastroenteritis)
Hospitalisation
Sepsis 6
GIVE 3 TAKE 3 Blood cultures Blood lactate Urine output Oxygen (aim sats 94-98% IV antibiotics IV fluid challenge
At least how many blood cultures should be taken in sepsis?
2
What is blood lactate a marker of?
Generalised Hypoperfusion
Severe sepsis
Poorer prognosis
General metabolism problems
What is low urine output a marker of?
Renal dysfunction
When should antibiotics be given in sepsis?
Within 1st hour of recognition
Two types of lactate
Type A = Hypoperfusion
Type B = mitochondrial toxins, malignancy, alcohol, metabolism errors
Fluid challenges require the definition of 4 compartments
- type of fluid to be administered
- rate of fluid infusion
- the end points (MAP > 65, HR < 110)
- the safety limits (e.g. development of pulmonary oedema)
What level of serum lactate is associated with increased severity of illness and poorer outcomes (even if hypotension not yet present)?
> 4mmol/L (36 mg/dL)
When to consider for HDU referral with sepsis
Low BP response to fluids Lactate > 2 despite fluid resuscitation Elevated creatinine Oliguira Liver dysfunction, Bil, PT, Plt Bilateral infiltrates, hypoxaemia
When to consider ITU for sepsis
Septic shock
Multi organ failure
What is CURB 65?
A score for mortality risk assessment in hospital for pneumonia
Scores for CURB65
1 point for each present;
- confusion
- raised blood urea nitrogen (>7)
- Raised RR (>30)
- Low BP (<60/90)
- Age >_65
Risk of death as follows
- 0 or 1 = low risk (<3% mortality risk)
- 2 = intermediate risk (3-15% mortality risk)
- 3 to 5 = high risk (>15% mortality risk)
What heart problem can sepsis lead to?
AF
What is the quickest way to determine lactate content?
VBG or ABG
