Infectious Disease and Sepsis
Core concepts
Understand sepsis as a dysregulated host response to infection with organ dysfunction, and the Surviving Sepsis approach: early recognition, blood cultures before antibiotics, broad-spectrum antibiotics within the first hour for septic shock, fluid resuscitation, and vasopressors for refractory hypotension. Learn the qSOFA and NEWS tools and their limitations. Cover the recognition of meningitis (and the role of dexamethasone and the timing of lumbar puncture), necrotising fasciitis, and the febrile returned traveller. Understand antimicrobial stewardship and the difference between colonisation and infection.
Traps
Examiners test giving antibiotics before cultures in a stable patient - cultures first, but never delay antibiotics in shock. In suspected meningitis with focal neurology or papilloedema, CT before lumbar puncture. Beware attributing sepsis to a single source without considering all possibilities. In necrotising fasciitis, pain out of proportion and rapid progression mandate urgent surgical debridement.
Rule of thumb
For septic shock, antibiotics within the first hour after cultures if possible; for stable sepsis, cultures first then antibiotics promptly. Fluid resuscitation comes before vasopressors.
Worked example
A 60-year-old with fever, hypotension, and a necrotic leg wound: resuscitate, take cultures, give broad-spectrum antibiotics including cover for anaerobes, and call surgery immediately for debridement.