4: Sepsis Flashcards
What is the difference between sepsis and endotoxaemia?
Sepsis is a systemic bacterial infection whereas endotoxaemia is LPS from bacterial cell wall in the blood
Does endotoxaemia or sepsis cause shock?
Both can
What conditions cause endotoxaemia in the horse?
FPT, neonatal septicaemia, intestinal ischaemia (so treat for this at the time of colic surgery)
In what species is endotoxaemia not seen?
Cats
When can cows get endotoxaemia?
Toxic mastitis
When can dogs get endotoxaemia?
Pyometra
What receptor recognises gram +ve?
TLR2
What receptor recognises gram -ve?
TLR4
How does endotoxaemia cause cell death?
Caspases activate cell death pathway
What normally restricts endotoxin to the intestinal lumen?
The mucosa
What usually removed endotoxin in the blood?
Hepatic macrophages
Which kind of bacteria produce LPS?
Gram -ves
What does the hydrophobic core do?
Protects lipid A of endotoxin in the centre
What increases host reaction to the endotoxin by 1000x?
A small glycoprotein
What also enhances response to the endotoxin?
CD14
What does MD2 do?
A TLR4 co-receptor which induces LPS to contact TLR4
What pathway is induced by TLR4?
NFkB
How many signalling pathways does TLR2 activate compared to TLR4?
Less
What are two examples of inflammatory mediators?
Cytokines and prostaglandins
What are signs of endotoxaemia?
Pain, increased heart rate, decreased intestinal motility, pale MMs, depression, fever, haemoconcentration, leukopaenia
Which drug can bind lipid A?
Polymixin B
What is a problem with using polymixin B?
Can be nephrotoxic, so care if decreased perfusion
Why can NSAIDs be good for shock?
Prevent prostglandin production, prevent early haemodynamic effects
Where is COX1 produced?
Constitutively expressed, produces PGs responsible for intestinal mucosa repair
Where is COX2 expressed?
Upregulated in inflammation and produces excessive PGs
What is a problem with COX-2 selective inhibitors?
Can worsen coagulopathy
Why is IVFT good in endotoxaemia?
Improves tissue perfusion, dilutes toxins
Why is amikacin good for endotoxaemia?
An aminoglycoside - rapidly kills without lysis
