AIM STEP 10
Student Memory Support
Topic 19 — Sepsis and Septic Shock
3rd Year MBBS • Infection and Inflammation • High-yield memory reinforcement and last-minute revision
1. High-Yield Flashcards
Tap each question to reveal the answer.
What is sepsis?
Life-threatening organ dysfunction caused by a dysregulated host response to infection.
What is septic shock?
A severe form of sepsis with profound circulatory, cellular and metabolic abnormalities causing persistent tissue hypoperfusion.
Is bacteremia required for the diagnosis of sepsis?
No. Sepsis is defined by infection-associated organ dysfunction, not by the presence of bacteria in blood.
Which major groups of microorganisms can cause sepsis?
Gram-negative bacteria, gram-positive bacteria and fungi.
Which gram-negative microbial component strongly activates innate immunity in sepsis?
Lipopolysaccharide, especially its lipid A component.
What do PAMPs do during sepsis?
They activate pattern-recognition receptors on innate immune cells and initiate inflammatory signaling.
What are DAMPs in the pathogenesis of sepsis?
Molecules released from injured host cells that further amplify innate immune activation.
Which important cytokines contribute to systemic inflammation in sepsis?
TNF and IL-1 are important mediators of inflammatory and endothelial activation.
How does endothelial injury contribute to hypotension in septic shock?
It causes vasodilation and increased vascular permeability, reducing vascular resistance and effective circulating volume.
Which mediator contributes importantly to systemic vasodilation in septic shock?
Nitric oxide.
Why do microthrombi worsen organ dysfunction in sepsis?
They obstruct the microcirculation and reduce tissue oxygen delivery.
Which coagulation complication may develop in severe sepsis?
Disseminated intravascular coagulation, with simultaneous microvascular thrombosis and consumption of clotting factors and platelets.
Why does urine output fall in septic shock?
Renal hypoperfusion and microcirculatory dysfunction impair kidney function.
Why may altered mental status occur in severe sepsis?
Cerebral hypoperfusion and systemic metabolic disturbance impair brain function.
What is the final common consequence of vasodilation, capillary leakage, microthrombi and cellular dysfunction?
Progressive tissue hypoperfusion and multiorgan dysfunction.
2. Mnemonics
Mnemonic Title: Major Microbial Groups Causing Sepsis
B-B-F
Meaning: Gram-negative Bacteria → Gram-positive Bacteria → Fungi.
Mnemonic Title: Main Circulatory Problems in Septic Shock
V-L-M
Meaning: Vasodilation → capillary Leakage → Microvascular thrombosis.
Mnemonic Title: Major Organ Dysfunction Clues
B-K-L
Meaning: Brain → confusion, Kidney → oliguria, Lung → respiratory dysfunction.
3. Memory Tables
Sepsis vs Septic Shock
| Feature | Sepsis | Septic Shock |
|---|---|---|
| Core concept | Organ dysfunction from dysregulated response to infection | Severe sepsis with profound circulatory and metabolic failure |
| Perfusion | May be impaired | Markedly impaired |
| Severity | Life-threatening | Most severe end of the septic process |
Clinical Finding and Mechanism
| Finding | Main Mechanism |
|---|---|
| Hypotension | Vasodilation + reduced effective circulating volume |
| Edema | Increased endothelial permeability |
| Oliguria | Renal hypoperfusion |
| Confusion | Cerebral hypoperfusion and metabolic dysfunction |
| Bleeding with microthrombi | Disseminated intravascular coagulation |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Sepsis means infection-associated dysregulated host response causing organ dysfunction.
- Bacteremia and sepsis are not synonymous.
- Gram-negative, gram-positive and fungal organisms can all cause sepsis.
- PAMPs and DAMPs activate pattern-recognition receptors.
- TNF and IL-1 contribute to systemic inflammatory and endothelial activation.
- Nitric oxide contributes to widespread vasodilation.
- Capillary leakage causes edema while reducing effective circulating volume.
- Microvascular thrombosis contributes directly to tissue hypoperfusion.
- DIC may produce both thrombosis and bleeding.
- Oliguria, confusion and respiratory dysfunction indicate important organ involvement.
- Septic shock reflects circulatory, cellular and metabolic failure rather than hypotension alone.
KMU Exam Trap: Negative blood cultures do not exclude sepsis if infection is accompanied by organ dysfunction.
5. Clinical Memory Hooks
Severe infection + confusion + oliguria
→
organ dysfunction suggests sepsis.
→
organ dysfunction suggests sepsis.
Hypotension + generalized edema
→
vasodilation plus endothelial leakage.
→
vasodilation plus endothelial leakage.
Bleeding from puncture sites + microvascular thrombi
→
disseminated intravascular coagulation.
→
disseminated intravascular coagulation.
Warm hypotensive patient with severe infection
→
widespread vasodilation from septic circulatory dysfunction.
→
widespread vasodilation from septic circulatory dysfunction.
6. ⭐ High-Yield Exam Points
- ⭐ Sepsis = dysregulated host response to infection causing life-threatening organ dysfunction.
- ⭐ Septic shock = profound circulatory, cellular and metabolic abnormalities with tissue hypoperfusion.
- ⭐ Lipopolysaccharide is an important trigger in gram-negative sepsis.
- ⭐ Vasodilation + capillary leakage are major causes of hypotension in septic shock.
- ⭐ Microvascular fibrin thrombi worsen organ perfusion and may progress to DIC.
- ⭐ Sepsis is not synonymous with bacteremia; organ dysfunction is the key defining concept.