Question 1

A 25-year-old male is admitted to the Emergency Department with fatigue, fevers and hypotension. He is now stable, requiring moderate dose vasopressor support, and has been transferred to the ICU for ongoing management.

Blood cultures taken on admission have grown Staphylococcus aureus, resistant to penicillin but sensitive to methicillin.

Outline your assessment and specific management related to the staphylococcal bacteraemia.

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College answer

Not available.


More explanation for the specific choice of investigations and antibiotics is available in the staphylococcal bacteremia chapter. Unfortunately, all efforts to produce a concise answer (one which could be written in the space of ten minutes) have failed, yielding to the irresistible completionist urge, and producing a "model answer" that is comprehensive and impossible. 

  • Assessment:
    • History looking for specific aetiological clues, as well as risk factors for complicated S.aureus bacteraemia or IE:
      • IV drug use
      • Immune compromise
      • Intravascular devices, prostheses or implants
      • Existing valvular disease
    • Physical examination:
      • A skin check, looking for:
        • Cellulitis and broken skin (ulcers, etc)
        • Signs of disseminated disease, eg. the peripheral stigmata of IE
      • Intravascular device assessment, focusing on:
        • the condition of the insertion site
        • the age of the line
        • the need for the line
      • Cardiovascular/respiratory examination, looking for:
        • New murmurs
        • New heart failure
        • Features of pneumonia
      • Neurological examination, looking for:
        • New focal neurodeficit (embolic CNS disease)
        • Peripheral neurodeficit suggestive of epidural abscess
      • Musculoskeletal examination, looking for:
        • Joint effusions
        • Myositis/fasciitis
        • Osteomyelitis/discitis
    • Bloods and biochemistry:
      • LFTs, to (also, to assess the effect the flucloxacillin is having on the liver)
      • EUC/CMP to establish baseline renal function and to detect any glomerulonephritis
      • Inflammatory markers (though some might say that with the bacteremia, you've identified that there is an infection, and you are committed to a long course of IV antibiotics, so what role could procalcitonin or CRP possibly play?)
    • Imaging studies:
      • Echocardiography, looking for IE
      • CT chest/abdomen/pelvis/brain with IV contrast, looking for metastatic foci of infection and septic emboli
      • MRI spine, looking for discitis osteomyelitis and epidural abscess
    • Microbiology investigations:
      • Repeat sets of blood cultures (ideally, repeated daily or second-daily until the bacteraemia is cleared)
      • Specific site sampling, including potentially:
        • Wound swabs
        • Line tip cultures
        • Abscess aspirates
        • Joint aspirates
        • Tissue cultures (eg. from valves)
  • Management:
    • Infectious diseases referral (reduces mortality!)
    • Antibiotic options:
      • ETG recommend flucloxacillin or cephazolin
      • For patients who are allergic to β-lactams,  desensitization therapy should be attempted, because the β-lactams are a clearly superior choice, and should be used wherever possible (instead of just resorting to vancomycin).  
    • Source control:
      • If at all possible, the source of the bacteremia needs to be removed. 
      • This may require:
        • Removal of suspected intravascular devices
        • Washout of infected joints
        • Explantation of infected prostheses
        • Valve replacement
    • Control potential sources:
      • It may actually be worthwhile removing all long-term intravascular devices (eg. PICC lines), waiting until the bacteraemia has resolved, and then resiting them after 2-3 blood cultures have returned negative results. 


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