Examkin

Question

Difficulty: MediumInfectious Diseases

A 57-year-old woman is admitted to the hospital due to a two-day history of diffuse abdominal pain, generalized weakness, and subjective fevers. Her past medical history is significant for alcohol-associated cirrhosis and esophageal varices. On physical examination, her temperature is 38.3°C (100.9°F), blood pressure is 105/65 mmHg, and heart rate is 102/min. Her abdomen is distended, tense, and diffusely tender to palpation, with shifting dullness present. Due to initial hypotension and concern for sepsis, she was empirically started on broad-spectrum coverage with intravenous piperacillin-tazobactam and daptomycin in the emergency department. A diagnostic paracentesis was also promptly performed, yielding cloudy fluid with an absolute neutrophil count of 750/mm3750/mm^3. It is now hospital day 3. The patient's fever has resolved and her abdominal pain has significantly improved. The ascitic fluid culture from admission now grows *Klebsiella pneumoniae*. Antimicrobial susceptibility testing indicates that the isolate is sensitive to ceftriaxone, cefepime, piperacillin-tazobactam, and meropenem. Which of the following is the most appropriate management of this patient's pharmacotherapy?

  1. Transition treatment to intravenous ceftriaxone monotherapyAnswer
  2. B
    Maintain the current empiric antimicrobial regimen to complete a standard treatment course
  3. C
    Halt daptomycin but persist with intravenous piperacillin-tazobactam
  4. D
    Switch the regimen to intravenous cefepime monotherapy
  5. E
    Switch the regimen to intravenous meropenem monotherapy

Answer

Transition treatment to intravenous ceftriaxone monotherapy.
The patient has spontaneous bacterial peritonitis (SBP) caused by *Klebsiella pneumoniae*. Initial empiric therapy for unstable patients with suspected sepsis is appropriately broad (e.g., piperacillin-tazobactam and daptomycin). However, a cornerstone of infectious disease management and antimicrobial stewardship is 'de-escalation.' Once culture and susceptibility results return, therapy should be narrowed to the most targeted, effective, and safe agent. In this case, the organism is susceptible to ceftriaxone, a third-generation cephalosporin that lacks unnecessary anti-pseudomonal or anti-anaerobic activity. Transitioning to ceftriaxone is the standard of care to treat the infection while minimizing collateral damage to the patient's microbiome.

Step-by-Step Solution

1
Diagnose the patient's condition upon admission based on clinical signs and ascitic fluid analysis.
The patient has spontaneous bacterial peritonitis (SBP), indicated by ascites, fever, abdominal pain, and an ascitic fluid absolute neutrophil count greater than 250/mm3250/mm^3.
Establishing the working diagnosis clarifies the site of infection and guides expected pathogens.
2
Evaluate the patient's initial empiric antimicrobial therapy in the context of the new culture data.
The patient was started on piperacillin-tazobactam and daptomycin, but cultures now show *Klebsiella pneumoniae* sensitive to several narrower agents.
Empiric therapy is designed to be broad to stabilize the patient, but must be tailored once definitive pathogen and susceptibility data are available.
3
Apply principles of antimicrobial stewardship to select the optimal definitive therapy.
Ceftriaxone provides targeted, effective coverage for the susceptible *K. pneumoniae* isolate without unnecessary anti-pseudomonal, anti-MRSA, or anti-anaerobic activity.
De-escalating to the narrowest effective agent minimizes toxicity, reduces the risk of *Clostridioides difficile* infection, and prevents the development of multi-drug resistant organisms.

Key Concept

Antimicrobial stewardship dictates de-escalating broad-spectrum empiric therapy to the narrowest effective targeted agent once culture and susceptibility data are available.
Estimated Time:1m 15s
Rate this question

Topics

Infectious Diseases

More questions from this topic