Sepsis and septic shock Flashcards
Define sepsis
Systemic illness caused by microbial invasion of normally sterile parts of the body
4 descriptions in traditional model of sepsis
SIRS
sepsis - SIRS and infection
severe sepsis - sepsis and end organ damage
septic shock - severe sepsis and hypotension
4 SIRS criteria and how many are required to make a diagnosis?
temp >38 or <36
HR - >90
RR>20 or PaCO2 <32
WBC >12 000 or <4000 or >10% bands
What from the traditional model of sepsis is no longer used and why?
severe sepsis - no prognostic indicators
Septic shock definition
sepsis with refractory hypotension on vasopressors and lactate > 2
List some causes of SIRS
pancreatitis
burns
trauma
sepsis
qSOFA
hypotension systolic bp <100mmHg
altered mental status
tachypnea RR>22/min
What does qSOFA tell us?
patients with suspected infection likely to have a prolonged ICU stay or die in hospital
Main management of sepsis is?
SEPSIS 6
The main 3 body’s defences (1 barrier +2 immune systems)
physical barrier - skin, mucosa, epithelial lining
innate immune system - IgA in GI trac, macrophages, dendritic cells
adaptive immune system - lymphocytes, Ig
3 features patients with sepsis have consistent with immunosuppression?
loss of delayed hypersensitivity
inability to clear infection
predisposition to nosocomial infection
Nosocomial?
hospital acquired
Change in sepsis syndrome over time in terms of inflammatory and anti inflammatory
initial increase in inflammatory mediators
later a shift towards anti inflammatory immunosuppressive phase
3 phases of sepsis syndrome
release of bacterial toxins
release of mediators
effects of specific excessive mediators
Commonly released gram -ve bacterial toxins
LPS
Commonly released gram positive bacterial toxins
MAMP (LTA) or super antigens
Endotoxin - LPS
gram negative needs a binding protein to bind to macrophages via toll like receptors
Endotoxin - LTA
gram positive do not need a binding protein
Exotoxin
small amounts of gram positive super antigen lead to a large amount of mediators being released - cascade effect
What can compensatory anti inflammatory mediators cause?
immunoparlysis
Example of main pro inflammatory mediator
TNF alpha
Example of main anti inflammatory mediator
IL IRA/4/10/13
Brief description of the role of pro inflammatory mediators
complement and coagulation
hyperthermia
vasodilation and endothelial cell-leucocyte adhesion
Brief description of the role of anti inflammatory mediators
Inhibit TNF alpha
inhibit coagulation and provide negative feedback
Pro inflammatory > compensatory anti inflammatory
septic shock with multi organ failure
Compensatory anti inflammatory > pro inflammatory
immunoparalysis with uncontrolled infection and multi organ failure
Organ dysfunction in sepsis
brain - confusion, psychosis, altered consciousness
blood - decrease platelets and c protein. Increase in D dimer and PT
kidneys - oliguria, anuria, increase in creatinine
Liver - jaundice, increase liver enzyme and PT, decrease bilirubin
lungs - tachypnoea, sats <90%
heart - tachycardia, hypotension
6 general features of sepsis
fever >38 degrees hypothermia <36 degrees tachycardia tachypnoea altered mental status hyperglycaemia
Who is hypothermia common in sepsis in?
elderly and young (and immunosuppressed)
Inflammatory variables in sepsis
leucocytosis leucopenia high CRP high procalcitonin normal WCC with >10% immature forms
Haemodynamic variables in sepsis
arterial hypotension
SvO2 >70%
Organ dysfunction variables in sepsis
thrombocytopenia arterial hypoxaemia oliguria increase creatinine ileus
Tissue perfusion variables in sepsis
high lactate
skin mottling and reduced capillary perfusion
4 effects of the host on sepsis presentation
age
co morbidities
immunosuppression
previous surgery
How the organism can affect the sepsis presentation
gram +ve or -ve
virulence factors
bioburden
How the environment can affect the presentation of sepsis
travel
occupation
hospitalisation
SEPSIS 6 basis
Take 3 - blood cultures, blood lactate, urine output
Give 3 - oxygen, IV antibiotics, IV fluid challenge
Use of blood cultures
microbiological diagnosis
spike in temp? take 2 sets
Lactate use
marker of generalised hypoperfusion/severe sepsis/poorer prognosis
What is low urine output a marker of?
renal dysfunction
what antibiotics to use and what to consider?
working diagnosis and local policy
consider allergy, CI, interactions, previous MRSA
Lactate type A
hypoperfusion
Lactate type B
mitochondrial toxins, alcohol, malignancy, metabolism
Why send a patient to HDU?
low bp responsive to fluids
lactate >2 despite fluid resuscitation
elevated creatinine, oliguria
liver dysfunction
Why send a patient to ITU?
Septic shock
multi organ failure
sedation, intubation, ventilation
CURB 65
pneumonia confusion urea resp rate >30 bp low >65
