3 Sepsis Flashcards
Sepsis is a syndrome defined as ?
life-threatening organ dysfunction due to the infecting pathogen and a dysregulated host response to infection
What does SIRS stand for ?
systemic inflammatory response syndrome
SIRS due to infection is known as what ?
sepsis
severe sepsis ?
sepsis plus at least one organ failure
septic shock ?
sepsis plus haemodynamic instability
SIRS is an inflammatory response to an insult e.g. give 4 examples
infection
trauma
infarction
malignancy
SIRS is the presence of 2 or more of what ?
- abnormal body temperature
- heart rate
- respiratory rate
- blood gas
- white blood cell count
Give the values of the following - that relate to the presence of SIRS
1. HR
2. RR
3. WCC
4. imature neutrophils
5. PaCO2
- HR > 90
- RR > 20
- WCC > 12
- immature neutrophils > 10%
- PaCO2 < 4.3KPa
SIRS = systemic inflammatory response syndrome
Apart from infection what else may SIRS also occur due to other pathophysiological events such as what ?
HB TRIP
* Haemorrhage
* Burns
* Trauma
* Reperfusion
* Ischaemia
* Pancreatitis
severe sepsis is an infectious disease state associated with what ?
MODS = multiple organ dysfunction syndrome
Severe sepsis is defined as sepsis with ?
sepsis-induced organ dysfunction or tissue hypoperfusion (reduced amt blood flow)
Severe sepsis is defined as sepsis with sepsis-induced** organ dysfunction or tissue hypoperfusion** which manifests as what ?
THE C between 2L’s & 2R’s
- thrombocytopenia
- hypotension
- elevated lactate levels
- lung injury
- liver dysfunction
- coagulopathy
- renal dysfunction
- reduced urine output
Septic shock is severe ……plus persistently……despite the administration of ….fluids
- sepsis
- low blood pressure
- intravenous
septic shock = severe sepsis plus the presence of the …….instability such as hypotension despite attempts to correct
*haemodynamic
In septic shock:
..1…compensatory mechanisms are overwhelmed resulting in abnormalities of ..2.. and/or ..3… metabolism
- physiological
- circulation
- cellular
2 types of septic shock ?
- compensated
- decompensated
Difference between compensated and decompensated septic shock ?
compensated = early stage of shock where compensatory mechanisms are still able to maintain tissue perfusion
decompensated = indicates stage where compensatory mechanisms fail, leading to worsening organ dysfunction and haemodynamic instability
Rarely pathogens causing sepsis
- fungal (candida)
- viral or parasites
Pathophysiology for sepsis involves a collection of responses to infection, one of them being infecting pathogens List 4 more :
- immune system
- coagulation cascade
- physiological compensation
- metabolic compensation
List what the immune response is activated by ?
- Pathogen associated molecular patterns (PAMPS)
- damage associated molecular patterns (DAMPS)
Give an overview of the inflammatory response
- insult
- trigger
- sensors and effector cells
- mediators and biomarkers
- impact on organ function
- outcome
- what is blood pressure proportional to ?
- BP = calculation?
- Cardiac output = calculation?
- blood pressure is proportional to : (heart rate X stroke volume) and systemic vascular resistance
- BP = (HR x SV) x SVR
- = HR x SV
Compensatory mechanisms to maintain blood pressure result in 3 increased what ?
- heart rate
- stroke volume
- systemic vascular resistance
Compensatory mechanisms to maintain blood pressure:
- largely driven by ..1.. system (….7.. and ..2.) = speed (3)?
- ..4…is also important
- …5..system is slowish
- …6…. hormone is slowish
- sympathetic nervous
- norepinephrine
- quick
- cortisol
- renin-angiotensin-aldosterone
- anti-diuretic
Vascular changes with sepsis ?
- vasodilation
- vasoconstriction
- vascular permeability
cellular events with sepsis ?
- increased adhesion of white blood cells
- cellular recruitment and activation of neutrophils
- chemical mediators modulate the inflammatory response
In sepsis the balance between what becomes disordered ?
pro-inflammatory and anti-inflammatory cytokines
Vasodilation leads to :
* reduced ..1… (peripheral) ..2..resistance
* potentially and eventually leads to fall in ..3…
* recognised by the presence of warm ..4…. (warm shock) (CRT normal)
* skin is …5… but vital organs are ..6….
- systemic
- vascular
- BP
- peripheries
- well perfused
- not
vasoconstriction may also occur especially why ?
sepsis progresses with sympathetic drive to increase peripheral SVR (lengthened CRT) to “re-direct” blood centrally to maintain vital organ perfusion
Vasodilation results in fall in …1… then compensatory …2… and increased …3… to try to maintain BP
- SVR
- tachycardia
- stroke volume
Compensated shock = normal …1.. treat ..2../ preferably well before decompensated shock = ….3… which is difficult to treat
- BP
- now
- low BP
Tachycardia will still occur even if there is ….1.. or ..2…
- vasoconstriction
- vasodilation
Pro-inflammatory cytokines damage the …1..endothelium leading to - (..2…syndrome) - …3… hypovolaemia
plus: reduced …4.. and increased …5…losses
- vascular
- capillary leak
- intra-vascular
- intake
- fluid
Intra-vascular hypovolaemia fruther crompromises ..1… , …2…. and …3…. increase to compensate
But reduced ….4…. return compromises ability to increase …5…
Leads to …6… in tissue perfusion lead to tissue …7… and tissue …8… and …9….glycolysis with …..10…acidosis
- BP
- HR
- SV
- venous
- stroke volume
- reduction
- ischaemia
- hypoxia
- anaerobic
- lactic
- In the early stages of sepsis how is cardiac output maintained by?
- what is seen ?
- an increase in HR and myocardial contractility (SV)
- ‘hyperdynamic circulation’
Cardiac outpute is maintained by an INC in HR and myocardial contractility …
Further increase in HR shortens …1… during which …2… perfusion occurs and so there is reduced …3…perfusion resulting in ….4… ischaemia and this further reduces ….5..output
- diastole
- diatolic coronary
- coronary artery
- myocardial
- cardiac
In the later stages of sepsis …
what directly impairs myocardial contractiliy , reducing CO further ?
pro-inflammatory cytokines in addition to hypoxia and acidosis
How does cardiac output (CO) change as sepsis progresses ?
1. In early stages of sepsis
2. In late stages of sepsis
3. further ….
- CO maintained due to compensatory increases in HR and SV (hyperdynamic circulation).
- Further increases in HR reduce the cardiac filling and coronary perfusion time, resulting in a decreased CO and myocardial ischaemia.
- further decrease in CO = The pro-inflammatory cytokines, hypoxia and acidosis all impair myocardial contracility in late sepsis
Summarise the pathophysiology of haemodynamic disturbances
1) Vasodilation:
* Reduced systemic vascular resistance
* Reduced/compromised blood pressure.
2) Capillary leak: Intra-vascular hypovolaemia. Reduced vital organ perfusion.
3) Compensatory mechanisms initially effective, then overwhelmed.
4) Intra-vascular hypovolaemia. Reduced venous return. Reduced coronary artery filling. Reduced myocardial
function. Reduced blood pressure. Reduced vital organ perfusion
5) Reduced vital organ perfusion
* Vital organ ischaemia
* Vital organ dysfunction
6) Peripheral vasoconstriction to re-direct blood to vital organs.
Summary of findings from examination / vitals examination
- Tachycardia
- Warm or cold peripheries (Capillary refill
- time. CRT)
- BP maintained (compensated)
- Low BP, compensatory mechanisms overwhelmed. (Decompensated)
- Reduced organ perfusion: Tissue hypoxia. Brain, heart, lungs, kidneys and liver.
How can sepsis affect the lungs ?
Increased metabolic demand leading to :
P A R R I S
- Pulmonary oedema
- Acute respiratory distress syndrome (ARDS)
- Respiratory failure
- rapid breathing (hyperventilation)
- Increased respiratory rate (tachypnoea)
- Shortness of breath (dyspnea)
Effects on tissues from sepsis ?
- tissue iscaehmia
- tissue hypoxia
- inefficient anaerobic respiration in tissues: reduced ATP
- cell and enzyme dysfunction
- tissue/organ dysfunction/ necrosis
- metabolic (lactic) acidosis