Sepsis
A life-threatening organ dysfunction caused by the body's dysregulated response to infection. Vasopressin is used as a vasopressor in septic shock to maintain blood pressure. Antimicrobial peptides (vancomycin, daptomycin, colistin) treat the underlying infections that cause sepsis.
Technical Context
Sepsis-3 definition: life-threatening organ dysfunction caused by dysregulated host response to infection (identified by ≥2 point increase in SOFA score). Septic shock: sepsis with persistent hypotension requiring vasopressors and lactate >2 mmol/L despite adequate fluid resuscitation (mortality approximately 40%). Antimicrobial peptide roles in sepsis: vancomycin (empirical gram-positive coverage in suspected MRSA sepsis — IV loading dose followed by trough-guided dosing), daptomycin (alternative for MRSA bacteraemia — 6-10mg/kg IV daily; bactericidal, may be preferred for endocarditis), colistin/polymyxin B (last-resort treatment for multidrug-resistant gram-negative sepsis — carbapenem-resistant Enterobacteriaceae, Pseudomonas, Acinetobacter), and vasopressin (0.03 units/min IV infusion as second-line vasopressor alongside norepinephrine — V1a-mediated vasoconstriction, potentially reducing catecholamine requirements). Sepsis management emphasises early antibiotics (within 1 hour of recognition) and source control.