Lesson 12: Sepsis, Invasive Infection and Antimicrobial Stewardship

Course 04: Respiratory Medicine and Infectious Disease

Lesson 12 of 14. Explore the diagnostic and management frameworks, work through the case, and finish the linked 10-question practice set. Urgent presentations require an emergency-care pathway and review of local professional scope.

Sepsis recognition

• Sepsis is life-threatening organ dysfunction due to a dysregulated response to infection; concerning findings include altered mental status, hypotension, hypoxemia, oliguria and poor perfusion.
• Do not equate fever alone with sepsis or assume absence of fever excludes severe infection, especially in older or immunocompromised patients.
• Consider pneumonia, urinary, abdominal, skin, catheter and CNS sources while managing shock without delay.

Emergency first principles

• Activate emergency/critical care pathways for suspected sepsis with organ dysfunction; assess lactate where appropriate, cultures and prompt treatment as directed by current pathways.
• Use appropriate broad empiric antimicrobials quickly for septic shock or high-likelihood severe sepsis with subsequent targeted reassessment; do not delay stabilization for ideal specimen collection.
• Fluids and vasopressors depend on perfusion, cardiac/renal context and reassessment; indiscriminate large-volume fluids can harm susceptible patients.

Stewardship and diagnostic testing

• Antibiotic use should be linked to a plausible bacterial syndrome and drug choice individualized to site, local resistance, renal function, allergy and interactions.
• Culture results can reflect colonization or contamination; interpret with source and presentation. Reassess treatment daily and de-escalate when possible.
• Document indication, duration/review point and return precautions; a broad-spectrum drug is not inherently better for mild infections.

Invasive infection and safety

• Meningitis signs, necrotizing soft tissue infection, febrile neutropenia and shock are urgent referral indications.
• Antibiotic complications include C. difficile, rash, anaphylaxis, renal injury, QT prolongation and drug interactions.
• Discuss uncertainty and follow-up honestly; obtain cultures and stewardship input when appropriate without withholding emergency care.

Applied clinical case

An 80-year-old with cough, confusion, cool extremities, BP 82/50 and new hypoxemia presents from a nursing home.

Clinical self-check

1. Can sepsis occur without fever?
2. When should cultures not delay antibiotics?
3. What is antibiotic de-escalation?

Current guidance and further learning

• Surviving Sepsis Campaign 2026 adult guideline (external)
• ATS: 2025 update to adult community-acquired pneumonia guideline (external)

Downloadable learning materials

• Respiratory and Sepsis Emergency Red Flags (PDF)
• Asthma and COPD: Diagnosis, Inhaler Care and Exacerbation Guide (PDF)
• Pneumonia, TB and Viral Infection Decision Guide (PDF)
• Pulmonary Diagnostics and Infectious Safety Reference (PDF)
• Complete Respiratory Medicine Handbook - 14 Lessons (PDF)