Flashcards in Sepsis Syndrome Deck (19)
What are the criteria for SIRS (systemic inflammatory response syndrome)? How many do you need?
1. HR >90f
2. RR >20 or PaCO2 18,000 or 10% immature
4. Temperature >38 or
What is sepsis?
SIRS + culture documented infection
What is severe sepsis?
sepsis + organ dysfunction or hypoperfusion
-acute alteration in mental status
What is septic shock?
What is the mortality from sepsis? What are the causes?
causes: bacterial, fungal, viral, parasitic infection and non-infection
What is the source of biologic activity in the gram negative outer membrane? What are other microbial factors that cause sepsis?
Microbial: LPS, cell wall, fungal and parasite components
How does the innate immune system play role in sepsis?
-transcription of proinflammatory cytokines, TNF alpha, IL-1
What role do macrophages play in the sepsis?
LBP-lipopolysaccharide binding protein
-acute phase reactant that binds to LPS
LPS-LBP complex binds to CD14 receptors and TLR4 dimer on inflammatory cells
activates genes for production of IL-1, TNF alpha and others
Soluble CD14-LPF-LBP complexes bind to endothelial cells
What are the two major cytokines in sepsis syndrome?
proinflammatory : tnf alpha, il-1, 2, 6,8, 10
Anti inflammatory: IL 6, 10
What are the causes of DIC and Fibrinolysis in Sepsis?
1. Coagulation cascade
a. Extrinsic-TNF: Increase expression of tissue factor on monocyte
b. Intrinsic-Factor 12 activated by microbial components including peptidoglycan, teichoic acid, and LPS
FIbrinolysis-TNF activation of plasminogen activator
-->result is DIC with microvascular thrombi and consumption coagulopathy
What are potential mediators of vasodilation in sepsis?
1. Kinin system activated through factor 12 conversion of prekallikrein to kallikrein
2. NO-inducible NO synthesis by LPS, IL1, TNF
3. Impaired secretion of antidiuretic hormone (vasopressin)
Result is hypotension
-redistribution of intravascular fluid volume
-increased endothelial permeability
What causes cell injury in sepsis ?
-microcirculatory lesions disrupts oxygenation
-receptor mediated neutrophil-endothelial adherence
2. Direct Cytotoxicity
-LPS, TNF alpha, NO damage mitochondria
-Enhanced in epithelium, T and B cells, lung
-Delayed in macrophages and neutrophils
What are the three components of shock?
1. System arterial Hypotension
-systolic 1.5 mmol/L
What are the key concepts in sepsis recognition?
2. Exam: skin, RR, urine output, mental status
3. SIRS findings
-WBC, decreased platelets
-decreased pO2 or SaO2
-elevated creatinine, bilirubin, INR
How do you manage sepsis?
-Fluid Replacement-500ml/30 minutes
30mL/Kg within the first 3 hours
2. Monitor tissue perfusion
3. Evaluation of source
5. Antimicrobial therapy* within first hour
-Norepinephrine-b and alpha adrenergic
-Vasopressin (antidiuretic hormone)
7. Support failing organ systems
Goal directed fluid resuscitation
MAP> or equal to 65
Urine output > equal .5
SCVO2 70% or mixed oxygen saturation SVO2 65%
Normalized lactate in patients with elevated lactate levels
What is in the first 3 hours of sepsis bundles?
1) measure lactate level
2) obtain blood cultures and administer antibiotics
3) administer 30mL/kg crystalloid for hypotension or lactate>4mmol/L
What needs to be done within the first 6 hours?
1. apply vasopressor
2. measure CVP ScVO2
3. remeasure lactate