Sepsis Flashcards
Systemic Inflammatory Response Syndrome
Massive inflammatory reaction from systemic cytokine release
What are the 4 components of SIRS?
– Temperature >38˚ C or 90
– Respiratory rate >20 or PaCO2 12,000 or 10% immature
– Heart rate of more than 90 beats per minute
– Abnormal white blood cell count (>12,000/µL or less than 4,000/µL or >10% immature [band] forms)
Sepsis Definition
SIRS plus culture documented infection
Severe Sepsis Definition
Sepsis plus organ dysfunction or hypoperfusion
Septic Shock
Refractory hypotension plus hypoperfusion abnormalities
What are some of the causes of SIRS?
- Bacteremia (bacterial, fungal, or parasitic infection)
- Burn injury
- Trauma or hemorrhage
- Acute pancreatitis
- Acute adrenal insufficiency
- Ischemic tissue injury
Is infection required for sepsis to occur?
NO
What are the organs most likely to fail in sepsis?
Lungs and Kidneys
What are the microbial structures that are connected to SIRS?
• Gram negative lipopolysaccharide
What are the components of LPS?
– Lipid A
– Core polysaccharide
– O-specific antigenic polysaccharide
What is the endotoxic part of LPS?
Lipid A
What are the host response mechanisms to microbe components that result in the inflammatory response?
Pattern recognition receptors – Four types: Toll-like receptors (TLRs), C-type lectin receptors, Retinoic acid inducible gene 1-like receptors (RLRs), Nucleotide-binding oligomerization domain-like receptors (NLRs)
What is the interaction of LPS and macrophages?
LBP-lipopolysaccharide binding protein will bind LPS and the LBP-LPS complex binds CD14 receptor TLR4 dimer on inflammatory cells - leads to the activation of genes for production of IL-1, TNF-alpha and others
What is the ultimate result of the activation of TLRs by microbial molecules?
NF-kB activation
What are the main cytokines acting in sepsis?
– TNF-alpha - central mediator with pleiotropic effects
– Interleukin-1 - endogenous pyrogen and also has pleiotropic effects
