Management of Acute Diverticulitis with Rising WBC Count

Assessment and Rationale

The American Gastroenterological Association recommends antibiotic treatment for patients with diverticulitis who have a baseline white blood cell count >15 × 10^9 cells per liter 1, 2
A WBC count >15 × 10^9 cells per liter is a risk factor for progression to complicated diverticulitis, requiring appropriate antibiotic coverage 1, 2, 3
For patients with acute diverticulitis requiring antibiotics, the regimen should include broad-spectrum agents with gram-negative and anaerobic coverage 2, 3
A combination of a fluoroquinolone (levofloxacin) and metronidazole is a recommended regimen for patients with penicillin allergy 2, 4

The patient has moderate to severe rectosigmoid diverticulitis with a rising WBC count (from 15 to 19), indicating worsening infection despite current antibiotic therapy 1, 2
Discontinuing cefepime and vancomycin and starting levofloxacin and metronidazole (previously effective for this patient) is a recommended approach 1, 2, 3
Tracking WBC count daily to ensure downward trend and assessing clinical symptoms (pain, nausea, fever) are important for monitoring response to the new antibiotic regimen 1, 2, 3

Patients with complicated diverticulitis or risk factors for progression (including WBC >15) require effective antibiotic therapy to reduce morbidity and mortality 1, 2
If the patient fails to respond to the new antibiotic regimen within 48-72 hours, consider surgical consultation and additional imaging to rule out complications such as abscess formation 1, 2, 3
The duration of antibiotic therapy should typically be 7-10 days for complicated diverticulitis, but may need to be extended based on clinical response 2, 3