Sepsis Flashcards
E.coli, Klebsiella, Enterobacteria, Pseudomonas aeruginosa and Neisseria gonorrhoea eater all what type of bacteria:
Gram -ve
Gram +ve?
Gram -ve
Streptococcus pneumoniae, Staphylococcus aureus and Listeria monocytogenes are all what type of bacteria:
Gram -ve
Gram +ve?
Gram +ve
List 3 changes that occur in the capillaries during sepsis.
Vasodilation
Intravascular coagulation
Increased permeability
What does TNF do in sepsis?
Mimics sepsis syndrome
What does interleukin 1 (IL-1) in sepsis?
Induce fever; increase endothelial and leukocyte adhesion; triggers procoagulant activity
What effects do IL-2, -4, -6 and -8 have in systemic inflammation?
Hypotension Leaky capillaries Reduced myocardial contractility Synthesis of acute phase proteins e.g. Fibrinogen Leukocyte chemo taxis
What does Nitric oxide cause in sepsis?
Hypotension
What are the key clinical features of septic shock?
Hypotension
Low urine output
Pyrexia
Tachycardia / pnoea
Define “shock”
Inadequate cellular perfusion and O2 uptake with consequent tissue hypoxia and organ failure
What 4 things can lead to organ failure in the late stages of shock?
Failure to autoregulate peripheral circulation
Abnormal distribution of blood flow with organs
Direct cellular toxicity
Prevention of O2 uptake and utilisation
Define sepsis
Suspected or proven infection with SIRS (systemic inflammatory response syndrome)
Define severe sepsis
Suspected or proven infection with SIRS plus organ dysfunction (perhaps hypotension that improves with fluid administration)
Define septic shock
Severe sepsis plus hypotension despite adequate volume resuscitation
Which anatomical systems are most commonly the source of infection in septic patients?
Respiratory
Intra-abdominal
Urinary
What are common clinical signs of severe sepsis?
Visible signs of acute inflammation (redness, swelling, heat, pain - if skin, mottling if vascular etc)
Systemic signs of inflammation - fever, tachycardia, tachypnoea, hypoxaemia, raised CRP, leukocytosis.
Organ failure - altered mental status, cardiac, respiratory, renal or gut failure
What does low urine output tell you?
That a patient is dehydrated or that the kidneys are not being well perfused and therefore other organs probably aren’t either
What are the main characteristics of innate immunity?
Rapid onset
Non-specific (Can damage healthy / normal tissues)
Consists of mechanical barriers, certain inflammatory cells, chemical mediators
What are the main cells that are involved in innate immunity?
Mast cells
Macrophages
Neutrophils
What is the initial role of a Toll-like receptor?
To stimulate an innate immune reaction once they have detected exotoxins, endotoxins or other microbial components (PAMPS)
What do cytokines do in acute inflammation?
Facilitate vascular changes and recruit other inflammatory cells (along with other mediators)
Which Toll-like receptors detect lipopolysaccharide?
TLR2 and TLR4
Which Toll-like receptor recognises gram +ve bacteria?
TLR2
Which Toll-like receptor recognises gram -ve bacteria?
TLR4
Name the chemical mediators of inflammation
Complement system Kinin system Vasoactive amines (histamine and serotonin) Prostaglandins, leukotrienes Cytokines and chemokines Nitric Oxide
What systemic effect do the inflammatory mediators prostaglandin, Nitric Oxide and histamine have?
Cause vasodilation
What systemic effect do vasoactive amines, the complement cascade, bradykinin and leukotrienes have in inflammation?
They increase vascular permeability