Examkin

Soru

Zorluk: OrtaGeneral Internal Medicine

A 6060-year-old woman is evaluated on the medical ward on day 44 of her hospitalization for a central line-associated bloodstream infection. She has a history of severe Crohn disease requiring extensive bowel resection and relies on home total parenteral nutrition delivered via a right internal jugular tunneled catheter. Upon admission, she presented with a temperature of 39.2∘39.2^\circ C (102.6∘102.6^\circ F), rigors, and hypotension. The catheter was immediately removed, and she was started empirically on intravenous vancomycin and cefepime. Today, she feels much better and has been afebrile for the past 3636 hours. Her blood pressure is 118/76118/76 mmHg and heart rate is 8282/min. The blood cultures obtained on admission from both the catheter and a peripheral vein have now finalized, demonstrating growth of methicillin-susceptible *Staphylococcus aureus* (MSSA) in all bottles. Susceptibility testing shows the isolate is resistant to penicillin but susceptible to cefazolin, ceftriaxone, oxacillin, and vancomycin. Which of the following is the most appropriate next step in antibiotic management?

  1. Discontinue vancomycin and cefepime, and initiate intravenous cefazolinCevap
  2. B
    Continue intravenous vancomycin and discontinue cefepime
  3. C
    Continue both intravenous vancomycin and cefepime
  4. D
    Discontinue vancomycin and cefepime, and initiate intravenous ceftriaxone
  5. E
    Discontinue vancomycin and cefepime, and initiate oral trimethoprim-sulfamethoxazole

Cevap

Discontinue vancomycin and cefepime, and initiate intravenous cefazolin
The correct approach is to discontinue the broad-spectrum empiric regimen (vancomycin and cefepime) and transition to definitive therapy with intravenous cefazolin. Antimicrobial stewardship requires de-escalating to the narrowest-spectrum, most effective agent once culture and susceptibility data are available. For methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, antistaphylococcal penicillins (e.g., nafcillin, oxacillin) or first-generation cephalosporins (e.g., cefazolin) are the drugs of choice. Cefazolin is highly effective, well-tolerated, and proven superior to vancomycin for MSSA, providing faster bloodstream clearance and lower mortality rates. Continuing vancomycin would be suboptimal care.

Adım Adım Çözüm

1
Identify the patient's current clinical status and microbiological data.
The patient has MSSA bacteremia, is clinically stable, and is currently receiving broad-spectrum empiric therapy with vancomycin and cefepime.
To establish the diagnosis and determine the need for antibiotic de-escalation based on final culture results.
2
Evaluate the susceptibility profile of the isolated organism to optimize therapy.
The MSSA isolate is susceptible to narrow-spectrum beta-lactams, including cefazolin and oxacillin.
To apply antimicrobial stewardship principles by selecting the most appropriate, narrowest-spectrum effective agent.
3
Select the optimal definitive antibiotic therapy for MSSA bacteremia.
Intravenous cefazolin (or an antistaphylococcal penicillin) is selected as the definitive treatment.
Beta-lactam antibiotics provide superior bactericidal activity and clinical outcomes compared to vancomycin for the treatment of MSSA bloodstream infections.

Anahtar Kavram

Antimicrobial stewardship dictates de-escalation from empiric vancomycin to a targeted beta-lactam (e.g., cefazolin, oxacillin, nafcillin) for the definitive treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.
Bu soruyu puanla

Konular

General Internal Medicine

Bu konudan daha fazla soru