Pathophysiology of Sepsis Flashcards
What is sepsis according to Sepsis-3?
Life-threatening organ dysfunction caused by a dysregulated host response to infection.
What do Pattern Recognition Receptors (PRRs) detect?
PAMPs (pathogen-associated molecular patterns) on pathogens.
What are common PAMPs involved in sepsis?
LPS (Gram-negative), peptidoglycan, flagellin, lipoteichoic acid, bacterial DNA.
Which immune receptors recognise PAMPs in sepsis?
Toll-like receptors (TLRs).
Which cytokines initiate the SIRS response?
TNF-α, IL-1, IL-6.
What is the role of IL-10 and TNF-β in sepsis?
They contribute to the compensatory anti-inflammatory response (CARS).
What is the gut hypothesis of sepsis?
Reduced gut perfusion increases permeability, allowing bacteria to translocate into the bloodstream.
What is the endotoxin-macrophage hypothesis?
Endotoxins trigger macrophages to release cytokines causing systemic inflammation.
What is the tissue hypoxia-microvascular hypothesis?
Microvascular damage leads to poor oxygen delivery, causing cell death and organ dysfunction.
What is the mitochondrial DNA hypothesis in sepsis?
Cell death releases mtDNA, triggering NET formation and immune overactivation.
What is the integrated hypothesis of sepsis?
Combines multiple mechanisms including gut leak, endotoxin, and mitochondrial pathways.
Which pathogens commonly cause sepsis?
S. pneumoniae, S. aureus, E. coli, Klebsiella spp., Pseudomonas aeruginosa.
What vascular changes occur during sepsis?
Vasodilation, capillary leak, and hypotension.
How do free radicals contribute to sepsis damage?
Produced by immune cells, they cause oxidative stress and tissue injury.
What is the role of endothelial cells in sepsis?
They release inflammatory mediators, increase permeability, and promote leukocyte adhesion.
What causes hypotension in sepsis?
Capillary leak and sustained vasodilation reduce blood volume and pressure.
What is the first stage of coagulation in sepsis?
Activation of complement, coagulation, and fibrinolysis systems.
What is the role of PAI-1 in sepsis?
It inhibits fibrinolysis, promoting thrombotic coagulopathy.
What is Disseminated Intravascular Coagulation (DIC)?
Widespread microthrombi block capillaries and use up clotting factors, leading to bleeding.
What leads to multiple organ failure in sepsis?
Tissue hypoxia, inflammation, and microvascular occlusion cause irreversible damage.
What early signs may indicate sepsis?
Fever, tachycardia, tachypnea, confusion, decreased urine output.
Who is at high risk for sepsis?
Elderly, neonates (babies in their first 28 days of life), immunocompromised, recent surgery, pregnant women.
How are dental infections linked to sepsis?
Severe infections may allow oral bacteria to enter the bloodstream and trigger sepsis.
What is the clinical definition of septic shock?
Persistent hypotension with high lactate despite fluid resuscitation.
How does sepsis lead to organ damage?
Reduced perfusion, inflammation, and oxygen depletion damage tissues.
How is sepsis managed in hospital?
IV fluids, antibiotics, vasopressors, and critical care support.
What is the role of antibiotic stewardship in sepsis?
Preserving antibiotic effectiveness for severe infections like sepsis.
What is the estimated annual death toll due to AMR by 2050?
10 million globally according to WHO projections.
Why is early recognition of sepsis crucial?
It significantly improves survival outcomes.
