Systemic Inflammation and Sepsis
Systemic inflammation and sepsis tests pathophysiology, Sepsis-3, resuscitation bundles and immunology.
Core rules
- Sepsis: dysregulated host response to infection causing life-threatening organ dysfunction, with SOFA ≥2.
- Septic shock: vasopressor-requiring hypotension with lactate >2 mmol/L despite adequate fluids.
- Initial resuscitation: 30 mL/kg crystalloid, balanced crystalloids preferred; norepinephrine first-line; add vasopressin; corticosteroids for refractory shock.
- Source control and antibiotics are time-critical.
- Immunoparalysis in late sepsis includes lymphopenia, HLA-DR downregulation and nosocomial infection.
Worked example
A patient with cholangitis has SOFA 4, lactate 4 mmol/L and MAP 55 mmHg after 30 mL/kg fluid. Start norepinephrine, give antibiotics and arrange ERCP drainage. Fluid overload would worsen oxygenation; the next priority is source control, not another fluid bolus.
Traps
- Giving starches or large chloride loads.
- Delaying vasopressors while giving repeated fluid boluses.
- Using lactate alone to diagnose sepsis.
- Missing fungal infection or source-control failure in non-responders.